Doc AWS SDK 예제 GitHub 리포지토리에서 더 많은 SDK 예제를 사용할 수 있습니다. [AWS](https://github.com/awsdocs/aws-doc-sdk-examples) 

기계 번역으로 제공되는 번역입니다. 제공된 번역과 원본 영어의 내용이 상충하는 경우에는 영어 버전이 우선합니다.

# 를 사용한 Amazon SQS 예제 SDK for .NET
<a name="csharp_3_sqs_code_examples"></a>

다음 코드 예제에서는 AWS SDK for .NET Amazon SQS를 사용하여 작업을 수행하고 일반적인 시나리오를 구현하는 방법을 보여줍니다.

*작업*은 대규모 프로그램에서 발췌한 코드이며 컨텍스트에 맞춰 실행해야 합니다. 작업은 개별 서비스 함수를 직접 호출하는 방법을 보여주며, 관련 시나리오의 컨텍스트에 맞는 작업을 볼 수 있습니다.

*시나리오*는 동일한 서비스 내에서 또는 다른 AWS 서비스와 결합된 상태에서 여러 함수를 직접적으로 호출하여 특정 태스크를 수행하는 방법을 보여주는 코드 예제입니다.

각 예시에는 전체 소스 코드에 대한 링크가 포함되어 있으며, 여기에서 컨텍스트에 맞춰 코드를 설정하고 실행하는 방법에 대한 지침을 찾을 수 있습니다.

**Topics**
+ [시작하기](#get_started)
+ [작업](#actions)
+ [시나리오](#scenarios)
+ [서버리스 예제](#serverless_examples)

## 시작하기
<a name="get_started"></a>

### Hello Amazon SNS
<a name="sqs_Hello_csharp_3_topic"></a>

다음 코드 예제에서는 Amazon SQS 사용을 시작하는 방법을 보여줍니다.

**SDK for .NET**  
 GitHub에 더 많은 내용이 있습니다. [AWS 코드 예 리포지토리](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/cross-service/TopicsAndQueues#code-examples)에서 전체 예를 찾고 설정 및 실행하는 방법을 배워보세요.

```
using Amazon.SQS;
using Amazon.SQS.Model;

namespace SQSActions;

public static class HelloSQS
{
    static async Task Main(string[] args)
    {
        var sqsClient = new AmazonSQSClient();

        Console.WriteLine($"Hello Amazon SQS! Following are some of your queues:");
        Console.WriteLine();

        // You can use await and any of the async methods to get a response.
        // Let's get the first five queues.
        var response = await sqsClient.ListQueuesAsync(
            new ListQueuesRequest()
            {
                MaxResults = 5
            });

        foreach (var queue in response.QueueUrls)
        {
            Console.WriteLine($"\tQueue Url: {queue}");
            Console.WriteLine();
        }
    }
}
```
+  API에 대한 세부 정보는 *AWS SDK for .NET API 참조*의 [ListQueues](https://docs.aws.amazon.com/goto/DotNetSDKV3/sqs-2012-11-05/ListQueues)를 참조하세요.

## 작업
<a name="actions"></a>

### `CreateQueue`
<a name="sqs_CreateQueue_csharp_3_topic"></a>

다음 코드 예시는 `CreateQueue`의 사용 방법을 보여줍니다.

**SDK for .NET**  
 GitHub에 더 많은 내용이 있습니다. [AWS 코드 예 리포지토리](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/cross-service/TopicsAndQueues#code-examples)에서 전체 예를 찾고 설정 및 실행하는 방법을 배워보세요.
특정 이름으로 대기열을 생성합니다.  

```
    /// <summary>
    /// Create a queue with a specific name.
    /// </summary>
    /// <param name="queueName">The name for the queue.</param>
    /// <param name="useFifoQueue">True to use a FIFO queue.</param>
    /// <returns>The url for the queue.</returns>
    public async Task<string> CreateQueueWithName(string queueName, bool useFifoQueue)
    {
        int maxMessage = 256 * 1024;
        var queueAttributes = new Dictionary<string, string>
        {
            {
                QueueAttributeName.MaximumMessageSize,
                maxMessage.ToString()
            }
        };

        var createQueueRequest = new CreateQueueRequest()
        {
            QueueName = queueName,
            Attributes = queueAttributes
        };

        if (useFifoQueue)
        {
            // Update the name if it is not correct for a FIFO queue.
            if (!queueName.EndsWith(".fifo"))
            {
                createQueueRequest.QueueName = queueName + ".fifo";
            }

            // Add an attribute for a FIFO queue.
            createQueueRequest.Attributes.Add(
                QueueAttributeName.FifoQueue, "true");
        }

        var createResponse = await _amazonSQSClient.CreateQueueAsync(
            new CreateQueueRequest()
            {
                QueueName = queueName
            });
        return createResponse.QueueUrl;
    }
```
Amazon SQS 대기열을 생성하고 메시지를 전송합니다.  

```
    using System;
    using System.Collections.Generic;
    using System.Threading.Tasks;
    using Amazon;
    using Amazon.SQS;
    using Amazon.SQS.Model;

    public class CreateSendExample
    {
        // Specify your AWS Region (an example Region is shown).
        private static readonly string QueueName = "Example_Queue";
        private static readonly RegionEndpoint ServiceRegion = RegionEndpoint.USWest2;
        private static IAmazonSQS client;

        public static async Task Main()
        {
            client = new AmazonSQSClient(ServiceRegion);
            var createQueueResponse = await CreateQueue(client, QueueName);

            string queueUrl = createQueueResponse.QueueUrl;

            Dictionary<string, MessageAttributeValue> messageAttributes = new Dictionary<string, MessageAttributeValue>
            {
                { "Title",   new MessageAttributeValue { DataType = "String", StringValue = "The Whistler" } },
                { "Author",  new MessageAttributeValue { DataType = "String", StringValue = "John Grisham" } },
                { "WeeksOn", new MessageAttributeValue { DataType = "Number", StringValue = "6" } },
            };

            string messageBody = "Information about current NY Times fiction bestseller for week of 12/11/2016.";

            var sendMsgResponse = await SendMessage(client, queueUrl, messageBody, messageAttributes);
        }

        /// <summary>
        /// Creates a new Amazon SQS queue using the queue name passed to it
        /// in queueName.
        /// </summary>
        /// <param name="client">An SQS client object used to send the message.</param>
        /// <param name="queueName">A string representing the name of the queue
        /// to create.</param>
        /// <returns>A CreateQueueResponse that contains information about the
        /// newly created queue.</returns>
        public static async Task<CreateQueueResponse> CreateQueue(IAmazonSQS client, string queueName)
        {
            var request = new CreateQueueRequest
            {
                QueueName = queueName,
                Attributes = new Dictionary<string, string>
                {
                    { "DelaySeconds", "60" },
                    { "MessageRetentionPeriod", "86400" },
                },
            };

            var response = await client.CreateQueueAsync(request);
            Console.WriteLine($"Created a queue with URL : {response.QueueUrl}");

            return response;
        }

        /// <summary>
        /// Sends a message to an SQS queue.
        /// </summary>
        /// <param name="client">An SQS client object used to send the message.</param>
        /// <param name="queueUrl">The URL of the queue to which to send the
        /// message.</param>
        /// <param name="messageBody">A string representing the body of the
        /// message to be sent to the queue.</param>
        /// <param name="messageAttributes">Attributes for the message to be
        /// sent to the queue.</param>
        /// <returns>A SendMessageResponse object that contains information
        /// about the message that was sent.</returns>
        public static async Task<SendMessageResponse> SendMessage(
            IAmazonSQS client,
            string queueUrl,
            string messageBody,
            Dictionary<string, MessageAttributeValue> messageAttributes)
        {
            var sendMessageRequest = new SendMessageRequest
            {
                DelaySeconds = 10,
                MessageAttributes = messageAttributes,
                MessageBody = messageBody,
                QueueUrl = queueUrl,
            };

            var response = await client.SendMessageAsync(sendMessageRequest);
            Console.WriteLine($"Sent a message with id : {response.MessageId}");

            return response;
        }
    }
```
+  API 세부 정보는 *AWS SDK for .NET API 참조*의 [CreateQueue](https://docs.aws.amazon.com/goto/DotNetSDKV3/sqs-2012-11-05/CreateQueue)를 참조하세요.

### `DeleteMessage`
<a name="sqs_DeleteMessage_csharp_3_topic"></a>

다음 코드 예시는 `DeleteMessage`의 사용 방법을 보여줍니다.

**SDK for .NET**  
 GitHub에 더 많은 내용이 있습니다. [AWS 코드 예 리포지토리](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/SQS#code-examples)에서 전체 예를 찾고 설정 및 실행하는 방법을 배워보세요.
Amazon SQS 대기열에서 메시지를 수신한 다음 메시지를 삭제합니다.  

```
        public static async Task Main()
        {
            // If the AWS Region you want to use is different from
            // the AWS Region defined for the default user, supply
            // the specify your AWS Region to the client constructor.
            var client = new AmazonSQSClient();
            string queueName = "Example_Queue";

            var queueUrl = await GetQueueUrl(client, queueName);
            Console.WriteLine($"The SQS queue's URL is {queueUrl}");

            var response = await ReceiveAndDeleteMessage(client, queueUrl);

            Console.WriteLine($"Message: {response.Messages[0]}");
        }

        /// <summary>
        /// Retrieve the queue URL for the queue named in the queueName
        /// property using the client object.
        /// </summary>
        /// <param name="client">The Amazon SQS client used to retrieve the
        /// queue URL.</param>
        /// <param name="queueName">A string representing  name of the queue
        /// for which to retrieve the URL.</param>
        /// <returns>The URL of the queue.</returns>
        public static async Task<string> GetQueueUrl(IAmazonSQS client, string queueName)
        {
            var request = new GetQueueUrlRequest
            {
                QueueName = queueName,
            };

            GetQueueUrlResponse response = await client.GetQueueUrlAsync(request);
            return response.QueueUrl;
        }

        /// <summary>
        /// Retrieves the message from the quque at the URL passed in the
        /// queueURL parameters using the client.
        /// </summary>
        /// <param name="client">The SQS client used to retrieve a message.</param>
        /// <param name="queueUrl">The URL of the queue from which to retrieve
        /// a message.</param>
        /// <returns>The response from the call to ReceiveMessageAsync.</returns>
        public static async Task<ReceiveMessageResponse> ReceiveAndDeleteMessage(IAmazonSQS client, string queueUrl)
        {
            // Receive a single message from the queue.
            var receiveMessageRequest = new ReceiveMessageRequest
            {
                AttributeNames = { "SentTimestamp" },
                MaxNumberOfMessages = 1,
                MessageAttributeNames = { "All" },
                QueueUrl = queueUrl,
                VisibilityTimeout = 0,
                WaitTimeSeconds = 0,
            };

            var receiveMessageResponse = await client.ReceiveMessageAsync(receiveMessageRequest);

            // Delete the received message from the queue.
            var deleteMessageRequest = new DeleteMessageRequest
            {
                QueueUrl = queueUrl,
                ReceiptHandle = receiveMessageResponse.Messages[0].ReceiptHandle,
            };

            await client.DeleteMessageAsync(deleteMessageRequest);

            return receiveMessageResponse;
        }
    }
```
+  API 세부 정보는 *AWS SDK for .NET API 참조*의 [DeleteMessage](https://docs.aws.amazon.com/goto/DotNetSDKV3/sqs-2012-11-05/DeleteMessage)를 참조하세요.

### `DeleteMessageBatch`
<a name="sqs_DeleteMessageBatch_csharp_3_topic"></a>

다음 코드 예시는 `DeleteMessageBatch`의 사용 방법을 보여줍니다.

**SDK for .NET**  
 GitHub에 더 많은 내용이 있습니다. [AWS 코드 예 리포지토리](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/cross-service/TopicsAndQueues#code-examples)에서 전체 예를 찾고 설정 및 실행하는 방법을 배워보세요.

```
    /// <summary>
    /// Delete a batch of messages from a queue by its url.
    /// </summary>
    /// <param name="queueUrl">The url of the queue.</param>
    /// <returns>True if successful.</returns>
    public async Task<bool> DeleteMessageBatchByUrl(string queueUrl, List<Message> messages)
    {
        var deleteRequest = new DeleteMessageBatchRequest()
        {
            QueueUrl = queueUrl,
            Entries = new List<DeleteMessageBatchRequestEntry>()
        };
        foreach (var message in messages)
        {
            deleteRequest.Entries.Add(new DeleteMessageBatchRequestEntry()
            {
                ReceiptHandle = message.ReceiptHandle,
                Id = message.MessageId
            });
        }

        var deleteResponse = await _amazonSQSClient.DeleteMessageBatchAsync(deleteRequest);

        return deleteResponse.Failed.Any();
    }
```
+  API 세부 정보는 *AWS SDK for .NET API 참조*의 [DeleteMessageBatch](https://docs.aws.amazon.com/goto/DotNetSDKV3/sqs-2012-11-05/DeleteMessageBatch)를 참조하세요.

### `DeleteQueue`
<a name="sqs_DeleteQueue_csharp_3_topic"></a>

다음 코드 예시는 `DeleteQueue`의 사용 방법을 보여줍니다.

**SDK for .NET**  
 GitHub에 더 많은 내용이 있습니다. [AWS 코드 예 리포지토리](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/cross-service/TopicsAndQueues#code-examples)에서 전체 예를 찾고 설정 및 실행하는 방법을 배워보세요.
URL을 사용하여 대기열을 삭제합니다.  

```
    /// <summary>
    /// Delete a queue by its URL.
    /// </summary>
    /// <param name="queueUrl">The url of the queue.</param>
    /// <returns>True if successful.</returns>
    public async Task<bool> DeleteQueueByUrl(string queueUrl)
    {
        var deleteResponse = await _amazonSQSClient.DeleteQueueAsync(
            new DeleteQueueRequest()
            {
                QueueUrl = queueUrl
            });
        return deleteResponse.HttpStatusCode == HttpStatusCode.OK;
    }
```
+  API 세부 정보는 *AWS SDK for .NET API 참조*의 [DeleteQueue](https://docs.aws.amazon.com/goto/DotNetSDKV3/sqs-2012-11-05/DeleteQueue)를 참조하세요.

### `GetQueueAttributes`
<a name="sqs_GetQueueAttributes_csharp_3_topic"></a>

다음 코드 예시는 `GetQueueAttributes`의 사용 방법을 보여줍니다.

**SDK for .NET**  
 GitHub에 더 많은 내용이 있습니다. [AWS 코드 예 리포지토리](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/cross-service/TopicsAndQueues#code-examples)에서 전체 예를 찾고 설정 및 실행하는 방법을 배워보세요.

```
    /// <summary>
    /// Get the ARN for a queue from its URL.
    /// </summary>
    /// <param name="queueUrl">The URL of the queue.</param>
    /// <returns>The ARN of the queue.</returns>
    public async Task<string> GetQueueArnByUrl(string queueUrl)
    {
        var getAttributesRequest = new GetQueueAttributesRequest()
        {
            QueueUrl = queueUrl,
            AttributeNames = new List<string>() { QueueAttributeName.QueueArn }
        };

        var getAttributesResponse = await _amazonSQSClient.GetQueueAttributesAsync(
            getAttributesRequest);

        return getAttributesResponse.QueueARN;
    }
```
+  API 세부 정보는 *AWS SDK for .NET API 참조*의 [GetQueueAttributes](https://docs.aws.amazon.com/goto/DotNetSDKV3/sqs-2012-11-05/GetQueueAttributes)를 참조하세요.

### `GetQueueUrl`
<a name="sqs_GetQueueUrl_csharp_3_topic"></a>

다음 코드 예시는 `GetQueueUrl`의 사용 방법을 보여줍니다.

**SDK for .NET**  
 GitHub에 더 많은 내용이 있습니다. [AWS 코드 예 리포지토리](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/SQS#code-examples)에서 전체 예를 찾고 설정 및 실행하는 방법을 배워보세요.

```
    using System;
    using System.Threading.Tasks;
    using Amazon.SQS;
    using Amazon.SQS.Model;

    public class GetQueueUrl
    {
        /// <summary>
        /// Initializes the Amazon SQS client object and then calls the
        /// GetQueueUrlAsync method to retrieve the URL of an Amazon SQS
        /// queue.
        /// </summary>
        public static async Task Main()
        {
            // If the Amazon SQS message queue is not in the same AWS Region as your
            // default user, you need to provide the AWS Region as a parameter to the
            // client constructor.
            var client = new AmazonSQSClient();

            string queueName = "New-Example-Queue";

            try
            {
                var response = await client.GetQueueUrlAsync(queueName);

                if (response.HttpStatusCode == System.Net.HttpStatusCode.OK)
                {
                    Console.WriteLine($"The URL for {queueName} is: {response.QueueUrl}");
                }
            }
            catch (QueueDoesNotExistException ex)
            {
                Console.WriteLine(ex.Message);
                Console.WriteLine($"The queue {queueName} was not found.");
            }
        }
    }
```
+  API 세부 정보는 *AWS SDK for .NET API 참조*의 [GetQueueUrl](https://docs.aws.amazon.com/goto/DotNetSDKV3/sqs-2012-11-05/GetQueueUrl)을 참조하세요.

### `ReceiveMessage`
<a name="sqs_ReceiveMessage_csharp_3_topic"></a>

다음 코드 예시는 `ReceiveMessage`의 사용 방법을 보여줍니다.

**SDK for .NET**  
 GitHub에 더 많은 내용이 있습니다. [AWS 코드 예 리포지토리](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/cross-service/TopicsAndQueues#code-examples)에서 전체 예를 찾고 설정 및 실행하는 방법을 배워보세요.
대기열의 URL을 사용하여 대기열에서 메시지를 수신합니다.  

```
    /// <summary>
    /// Receive messages from a queue by its URL.
    /// </summary>
    /// <param name="queueUrl">The url of the queue.</param>
    /// <returns>The list of messages.</returns>
    public async Task<List<Message>> ReceiveMessagesByUrl(string queueUrl, int maxMessages)
    {
        // Setting WaitTimeSeconds to non-zero enables long polling.
        // For information about long polling, see
        // https://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/sqs-short-and-long-polling.html
        var messageResponse = await _amazonSQSClient.ReceiveMessageAsync(
            new ReceiveMessageRequest()
            {
                QueueUrl = queueUrl,
                MaxNumberOfMessages = maxMessages,
                WaitTimeSeconds = 1
            });
        return messageResponse.Messages;
    }
```
Amazon SQS 대기열에서 메시지를 수신한 다음 메시지를 삭제합니다.  

```
        public static async Task Main()
        {
            // If the AWS Region you want to use is different from
            // the AWS Region defined for the default user, supply
            // the specify your AWS Region to the client constructor.
            var client = new AmazonSQSClient();
            string queueName = "Example_Queue";

            var queueUrl = await GetQueueUrl(client, queueName);
            Console.WriteLine($"The SQS queue's URL is {queueUrl}");

            var response = await ReceiveAndDeleteMessage(client, queueUrl);

            Console.WriteLine($"Message: {response.Messages[0]}");
        }

        /// <summary>
        /// Retrieve the queue URL for the queue named in the queueName
        /// property using the client object.
        /// </summary>
        /// <param name="client">The Amazon SQS client used to retrieve the
        /// queue URL.</param>
        /// <param name="queueName">A string representing  name of the queue
        /// for which to retrieve the URL.</param>
        /// <returns>The URL of the queue.</returns>
        public static async Task<string> GetQueueUrl(IAmazonSQS client, string queueName)
        {
            var request = new GetQueueUrlRequest
            {
                QueueName = queueName,
            };

            GetQueueUrlResponse response = await client.GetQueueUrlAsync(request);
            return response.QueueUrl;
        }

        /// <summary>
        /// Retrieves the message from the quque at the URL passed in the
        /// queueURL parameters using the client.
        /// </summary>
        /// <param name="client">The SQS client used to retrieve a message.</param>
        /// <param name="queueUrl">The URL of the queue from which to retrieve
        /// a message.</param>
        /// <returns>The response from the call to ReceiveMessageAsync.</returns>
        public static async Task<ReceiveMessageResponse> ReceiveAndDeleteMessage(IAmazonSQS client, string queueUrl)
        {
            // Receive a single message from the queue.
            var receiveMessageRequest = new ReceiveMessageRequest
            {
                AttributeNames = { "SentTimestamp" },
                MaxNumberOfMessages = 1,
                MessageAttributeNames = { "All" },
                QueueUrl = queueUrl,
                VisibilityTimeout = 0,
                WaitTimeSeconds = 0,
            };

            var receiveMessageResponse = await client.ReceiveMessageAsync(receiveMessageRequest);

            // Delete the received message from the queue.
            var deleteMessageRequest = new DeleteMessageRequest
            {
                QueueUrl = queueUrl,
                ReceiptHandle = receiveMessageResponse.Messages[0].ReceiptHandle,
            };

            await client.DeleteMessageAsync(deleteMessageRequest);

            return receiveMessageResponse;
        }
    }
```
+  API 세부 정보는 *AWS SDK for .NET API 참조*의 [ReceiveMessage](https://docs.aws.amazon.com/goto/DotNetSDKV3/sqs-2012-11-05/ReceiveMessage)를 참조하세요.

### `SendMessage`
<a name="sqs_SendMessage_csharp_3_topic"></a>

다음 코드 예시는 `SendMessage`의 사용 방법을 보여줍니다.

**SDK for .NET**  
 GitHub에 더 많은 내용이 있습니다. [AWS 코드 예 리포지토리](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/SQS#code-examples)에서 전체 예를 찾고 설정 및 실행하는 방법을 배워보세요.
Amazon SQS 대기열을 생성하고 메시지를 전송합니다.  

```
    using System;
    using System.Collections.Generic;
    using System.Threading.Tasks;
    using Amazon;
    using Amazon.SQS;
    using Amazon.SQS.Model;

    public class CreateSendExample
    {
        // Specify your AWS Region (an example Region is shown).
        private static readonly string QueueName = "Example_Queue";
        private static readonly RegionEndpoint ServiceRegion = RegionEndpoint.USWest2;
        private static IAmazonSQS client;

        public static async Task Main()
        {
            client = new AmazonSQSClient(ServiceRegion);
            var createQueueResponse = await CreateQueue(client, QueueName);

            string queueUrl = createQueueResponse.QueueUrl;

            Dictionary<string, MessageAttributeValue> messageAttributes = new Dictionary<string, MessageAttributeValue>
            {
                { "Title",   new MessageAttributeValue { DataType = "String", StringValue = "The Whistler" } },
                { "Author",  new MessageAttributeValue { DataType = "String", StringValue = "John Grisham" } },
                { "WeeksOn", new MessageAttributeValue { DataType = "Number", StringValue = "6" } },
            };

            string messageBody = "Information about current NY Times fiction bestseller for week of 12/11/2016.";

            var sendMsgResponse = await SendMessage(client, queueUrl, messageBody, messageAttributes);
        }

        /// <summary>
        /// Creates a new Amazon SQS queue using the queue name passed to it
        /// in queueName.
        /// </summary>
        /// <param name="client">An SQS client object used to send the message.</param>
        /// <param name="queueName">A string representing the name of the queue
        /// to create.</param>
        /// <returns>A CreateQueueResponse that contains information about the
        /// newly created queue.</returns>
        public static async Task<CreateQueueResponse> CreateQueue(IAmazonSQS client, string queueName)
        {
            var request = new CreateQueueRequest
            {
                QueueName = queueName,
                Attributes = new Dictionary<string, string>
                {
                    { "DelaySeconds", "60" },
                    { "MessageRetentionPeriod", "86400" },
                },
            };

            var response = await client.CreateQueueAsync(request);
            Console.WriteLine($"Created a queue with URL : {response.QueueUrl}");

            return response;
        }

        /// <summary>
        /// Sends a message to an SQS queue.
        /// </summary>
        /// <param name="client">An SQS client object used to send the message.</param>
        /// <param name="queueUrl">The URL of the queue to which to send the
        /// message.</param>
        /// <param name="messageBody">A string representing the body of the
        /// message to be sent to the queue.</param>
        /// <param name="messageAttributes">Attributes for the message to be
        /// sent to the queue.</param>
        /// <returns>A SendMessageResponse object that contains information
        /// about the message that was sent.</returns>
        public static async Task<SendMessageResponse> SendMessage(
            IAmazonSQS client,
            string queueUrl,
            string messageBody,
            Dictionary<string, MessageAttributeValue> messageAttributes)
        {
            var sendMessageRequest = new SendMessageRequest
            {
                DelaySeconds = 10,
                MessageAttributes = messageAttributes,
                MessageBody = messageBody,
                QueueUrl = queueUrl,
            };

            var response = await client.SendMessageAsync(sendMessageRequest);
            Console.WriteLine($"Sent a message with id : {response.MessageId}");

            return response;
        }
    }
```
+  API 세부 정보는 *AWS SDK for .NET API 참조*의 [SendMessage](https://docs.aws.amazon.com/goto/DotNetSDKV3/sqs-2012-11-05/SendMessage)를 참조하세요.

### `SetQueueAttributes`
<a name="sqs_SetQueueAttributes_csharp_3_topic"></a>

다음 코드 예시는 `SetQueueAttributes`의 사용 방법을 보여줍니다.

**SDK for .NET**  
 GitHub에 더 많은 내용이 있습니다. [AWS 코드 예 리포지토리](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/cross-service/TopicsAndQueues#code-examples)에서 전체 예를 찾고 설정 및 실행하는 방법을 배워보세요.
주제에 대한 대기열의 정책 속성을 설정합니다.  

```
    /// <summary>
    /// Set the policy attribute of a queue for a topic.
    /// </summary>
    /// <param name="queueArn">The ARN of the queue.</param>
    /// <param name="topicArn">The ARN of the topic.</param>
    /// <param name="queueUrl">The url for the queue.</param>
    /// <returns>True if successful.</returns>
    public async Task<bool> SetQueuePolicyForTopic(string queueArn, string topicArn, string queueUrl)
    {
        var queuePolicy = "{" +
                                "\"Version\": \"2012-10-17\"," +
                                "\"Statement\": [{" +
                                     "\"Effect\": \"Allow\"," +
                                     "\"Principal\": {" +
                                         $"\"Service\": " +
                                             "\"sns.amazonaws.com\"" +
                                            "}," +
                                     "\"Action\": \"sqs:SendMessage\"," +
                                     $"\"Resource\": \"{queueArn}\"," +
                                      "\"Condition\": {" +
                                           "\"ArnEquals\": {" +
                                                $"\"aws:SourceArn\": \"{topicArn}\"" +
                                            "}" +
                                        "}" +
                                "}]" +
                             "}";
        var attributesResponse = await _amazonSQSClient.SetQueueAttributesAsync(
            new SetQueueAttributesRequest()
            {
                QueueUrl = queueUrl,
                Attributes = new Dictionary<string, string>() { { "Policy", queuePolicy } }
            });
        return attributesResponse.HttpStatusCode == HttpStatusCode.OK;
    }
```
+  API 세부 정보는 *AWS SDK for .NET API 참조*의 [SetQueueAttributes](https://docs.aws.amazon.com/goto/DotNetSDKV3/sqs-2012-11-05/SetQueueAttributes)를 참조하세요.

## 시나리오
<a name="scenarios"></a>

### 대기열에 메시지 게시
<a name="sqs_Scenario_TopicsAndQueues_csharp_3_topic"></a>

다음 코드 예제에서는 다음과 같은 작업을 수행하는 방법을 보여줍니다.
+ 주제(FIFO 또는 비 FIFO)를 생성합니다.
+ 필터 적용 옵션을 사용하여 여러 개의 대기열로 주제를 구독합니다.
+ 주제에 메시지를 게시합니다.
+ 대기열에서 받은 메시지를 폴링합니다.

**SDK for .NET**  
 GitHub에 더 많은 내용이 있습니다. [AWS 코드 예 리포지토리](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/cross-service/TopicsAndQueues#code-examples)에서 전체 예를 찾고 설정 및 실행하는 방법을 배워보세요.
명령 프롬프트에서 대화형 시나리오를 실행합니다.  

```
/// <summary>
/// Console application to run a feature scenario for topics and queues.
/// </summary>
public static class TopicsAndQueues
{
    private static bool _useFifoTopic = false;
    private static bool _useContentBasedDeduplication = false;
    private static string _topicName = null!;
    private static string _topicArn = null!;

    private static readonly int _queueCount = 2;
    private static readonly string[] _queueUrls = new string[_queueCount];
    private static readonly string[] _subscriptionArns = new string[_queueCount];
    private static readonly string[] _tones = { "cheerful", "funny", "serious", "sincere" };
    public static SNSWrapper SnsWrapper { get; set; } = null!;
    public static SQSWrapper SqsWrapper { get; set; } = null!;
    public static bool UseConsole { get; set; } = true;
    static async Task Main(string[] args)
    {
        // Set up dependency injection for Amazon EventBridge.
        using var host = Host.CreateDefaultBuilder(args)
            .ConfigureLogging(logging =>
                logging.AddFilter("System", LogLevel.Debug)
                    .AddFilter<DebugLoggerProvider>("Microsoft", LogLevel.Information)
                    .AddFilter<ConsoleLoggerProvider>("Microsoft", LogLevel.Trace))
            .ConfigureServices((_, services) =>
                services.AddAWSService<IAmazonSQS>()
                    .AddAWSService<IAmazonSimpleNotificationService>()
                    .AddTransient<SNSWrapper>()
                    .AddTransient<SQSWrapper>()
            )
            .Build();

        ServicesSetup(host);
        PrintDescription();

        await RunScenario();

    }

    /// <summary>
    /// Populate the services for use within the console application.
    /// </summary>
    /// <param name="host">The services host.</param>
    private static void ServicesSetup(IHost host)
    {
        SnsWrapper = host.Services.GetRequiredService<SNSWrapper>();
        SqsWrapper = host.Services.GetRequiredService<SQSWrapper>();
    }

    /// <summary>
    /// Run the scenario for working with topics and queues.
    /// </summary>
    /// <returns>True if successful.</returns>
    public static async Task<bool> RunScenario()
    {
        try
        {
            await SetupTopic();

            await SetupQueues();

            await PublishMessages();

            foreach (var queueUrl in _queueUrls)
            {
                var messages = await PollForMessages(queueUrl);
                if (messages.Any())
                {
                    await DeleteMessages(queueUrl, messages);
                }
            }
            await CleanupResources();

            Console.WriteLine("Messaging with topics and queues scenario is complete.");
            return true;
        }
        catch (Exception ex)
        {
            Console.WriteLine(new string('-', 80));
            Console.WriteLine($"There was a problem running the scenario: {ex.Message}");
            await CleanupResources();
            Console.WriteLine(new string('-', 80));
            return false;
        }
    }

    /// <summary>
    /// Print a description for the tasks in the scenario.
    /// </summary>
    /// <returns>Async task.</returns>
    private static void PrintDescription()
    {
        Console.WriteLine(new string('-', 80));
        Console.WriteLine($"Welcome to messaging with topics and queues.");

        Console.WriteLine(new string('-', 80));
        Console.WriteLine($"In this scenario, you will create an SNS topic and subscribe {_queueCount} SQS queues to the topic." +
                          $"\r\nYou can select from several options for configuring the topic and the subscriptions for the 2 queues." +
                          $"\r\nYou can then post to the topic and see the results in the queues.\r\n");

        Console.WriteLine(new string('-', 80));
    }

    /// <summary>
    /// Set up the SNS topic to be used with the queues.
    /// </summary>
    /// <returns>Async task.</returns>
    private static async Task<string> SetupTopic()
    {
        Console.WriteLine(new string('-', 80));
        Console.WriteLine($"SNS topics can be configured as FIFO (First-In-First-Out)." +
                          $"\r\nFIFO topics deliver messages in order and support deduplication and message filtering." +
                          $"\r\nYou can then post to the topic and see the results in the queues.\r\n");

        _useFifoTopic = GetYesNoResponse("Would you like to work with FIFO topics?");

        if (_useFifoTopic)
        {
            Console.WriteLine(new string('-', 80));
            _topicName = GetUserResponse("Enter a name for your SNS topic: ", "example-topic");
            Console.WriteLine(
                "Because you have selected a FIFO topic, '.fifo' must be appended to the topic name.\r\n");

            Console.WriteLine(new string('-', 80));
            Console.WriteLine($"Because you have chosen a FIFO topic, deduplication is supported." +
                              $"\r\nDeduplication IDs are either set in the message or automatically generated " +
                              $"\r\nfrom content using a hash function.\r\n" +
                              $"\r\nIf a message is successfully published to an SNS FIFO topic, any message " +
                              $"\r\npublished and determined to have the same deduplication ID, " +
                              $"\r\nwithin the five-minute deduplication interval, is accepted but not delivered.\r\n" +
                              $"\r\nFor more information about deduplication, " +
                              $"\r\nsee https://docs.aws.amazon.com/sns/latest/dg/fifo-message-dedup.html.");

            _useContentBasedDeduplication = GetYesNoResponse("Use content-based deduplication instead of entering a deduplication ID?");
            Console.WriteLine(new string('-', 80));
        }

        _topicArn = await SnsWrapper.CreateTopicWithName(_topicName, _useFifoTopic, _useContentBasedDeduplication);

        Console.WriteLine($"Your new topic with the name {_topicName}" +
                          $"\r\nand Amazon Resource Name (ARN) {_topicArn}" +
                          $"\r\nhas been created.\r\n");

        Console.WriteLine(new string('-', 80));
        return _topicArn;
    }

    /// <summary>
    /// Set up the queues.
    /// </summary>
    /// <returns>Async task.</returns>
    private static async Task SetupQueues()
    {
        Console.WriteLine(new string('-', 80));
        Console.WriteLine($"Now you will create {_queueCount} Amazon Simple Queue Service (Amazon SQS) queues to subscribe to the topic.");

        // Repeat this section for each queue.
        for (int i = 0; i < _queueCount; i++)
        {
            var queueName = GetUserResponse("Enter a name for an Amazon SQS queue: ", $"example-queue-{i}");
            if (_useFifoTopic)
            {
                // Only explain this once.
                if (i == 0)
                {
                    Console.WriteLine(
                        "Because you have selected a FIFO topic, '.fifo' must be appended to the queue name.");
                }

                var queueUrl = await SqsWrapper.CreateQueueWithName(queueName, _useFifoTopic);

                _queueUrls[i] = queueUrl;

                Console.WriteLine($"Your new queue with the name {queueName}" +
                                  $"\r\nand queue URL {queueUrl}" +
                                  $"\r\nhas been created.\r\n");

                if (i == 0)
                {
                    Console.WriteLine(
                        $"The queue URL is used to retrieve the queue ARN,\r\n" +
                        $"which is used to create a subscription.");
                    Console.WriteLine(new string('-', 80));
                }

                var queueArn = await SqsWrapper.GetQueueArnByUrl(queueUrl);

                if (i == 0)
                {
                    Console.WriteLine(
                        $"An AWS Identity and Access Management (IAM) policy must be attached to an SQS queue, enabling it to receive\r\n" +
                        $"messages from an SNS topic");
                }

                await SqsWrapper.SetQueuePolicyForTopic(queueArn, _topicArn, queueUrl);

                await SetupFilters(i, queueArn, queueName);
            }
        }

        Console.WriteLine(new string('-', 80));
    }

    /// <summary>
    /// Set up filters with user options for a queue.
    /// </summary>
    /// <param name="queueCount">The number of this queue.</param>
    /// <param name="queueArn">The ARN of the queue.</param>
    /// <param name="queueName">The name of the queue.</param>
    /// <returns>Async Task.</returns>
    public static async Task SetupFilters(int queueCount, string queueArn, string queueName)
    {
        if (_useFifoTopic)
        {
            Console.WriteLine(new string('-', 80));
            // Only explain this once.
            if (queueCount == 0)
            {
                Console.WriteLine(
                    "Subscriptions to a FIFO topic can have filters." +
                    "If you add a filter to this subscription, then only the filtered messages " +
                    "will be received in the queue.");

                Console.WriteLine(
                    "For information about message filtering, " +
                    "see https://docs.aws.amazon.com/sns/latest/dg/sns-message-filtering.html");

                Console.WriteLine(
                    "For this example, you can filter messages by a" +
                    "TONE attribute.");
            }

            var useFilter = GetYesNoResponse($"Filter messages for {queueName}'s subscription to the topic?");

            string? filterPolicy = null;
            if (useFilter)
            {
                filterPolicy = CreateFilterPolicy();
            }
            var subscriptionArn = await SnsWrapper.SubscribeTopicWithFilter(_topicArn, filterPolicy,
                queueArn);
            _subscriptionArns[queueCount] = subscriptionArn;

            Console.WriteLine(
                $"The queue {queueName} has been subscribed to the topic {_topicName} " +
                $"with the subscription ARN {subscriptionArn}");
            Console.WriteLine(new string('-', 80));
        }
    }

    /// <summary>
    /// Use user input to create a filter policy for a subscription.
    /// </summary>
    /// <returns>The serialized filter policy.</returns>
    public static string CreateFilterPolicy()
    {
        Console.WriteLine(new string('-', 80));
        Console.WriteLine(
            $"You can filter messages by one or more of the following" +
            $"TONE attributes.");

        List<string> filterSelections = new List<string>();

        var selectionNumber = 0;
        do
        {
            Console.WriteLine(
                $"Enter a number to add a TONE filter, or enter 0 to stop adding filters.");
            for (int i = 0; i < _tones.Length; i++)
            {
                Console.WriteLine($"\t{i + 1}. {_tones[i]}");
            }

            var selection = GetUserResponse("", filterSelections.Any() ? "0" : "1");
            int.TryParse(selection, out selectionNumber);
            if (selectionNumber > 0 && !filterSelections.Contains(_tones[selectionNumber - 1]))
            {
                filterSelections.Add(_tones[selectionNumber - 1]);
            }
        } while (selectionNumber != 0);

        var filters = new Dictionary<string, List<string>>
        {
            { "tone", filterSelections }
        };
        string filterPolicy = JsonSerializer.Serialize(filters);
        return filterPolicy;
    }

    /// <summary>
    /// Publish messages using user settings.
    /// </summary>
    /// <returns>Async task.</returns>
    public static async Task PublishMessages()
    {
        Console.WriteLine("Now we can publish messages.");

        var keepSendingMessages = true;
        string? deduplicationId = null;
        string? toneAttribute = null;
        while (keepSendingMessages)
        {
            Console.WriteLine();
            var message = GetUserResponse("Enter a message to publish.", "This is a sample message");

            if (_useFifoTopic)
            {
                Console.WriteLine("Because you are using a FIFO topic, you must set a message group ID." +
                                  "\r\nAll messages within the same group will be received in the order " +
                                  "they were published.");

                Console.WriteLine();
                var messageGroupId = GetUserResponse("Enter a message group ID for this message:", "1");

                if (!_useContentBasedDeduplication)
                {
                    Console.WriteLine("Because you are not using content-based deduplication, " +
                                      "you must enter a deduplication ID.");

                    Console.WriteLine("Enter a deduplication ID for this message.");
                    deduplicationId = GetUserResponse("Enter a deduplication ID for this message.", "1");
                }

                if (GetYesNoResponse("Add an attribute to this message?"))
                {
                    Console.WriteLine("Enter a number for an attribute.");
                    for (int i = 0; i < _tones.Length; i++)
                    {
                        Console.WriteLine($"\t{i + 1}. {_tones[i]}");
                    }

                    var selection = GetUserResponse("", "1");
                    int.TryParse(selection, out var selectionNumber);

                    if (selectionNumber > 0 && selectionNumber < _tones.Length)
                    {
                        toneAttribute = _tones[selectionNumber - 1];
                    }
                }

                var messageID = await SnsWrapper.PublishToTopicWithAttribute(
                    _topicArn, message, "tone", toneAttribute, deduplicationId, messageGroupId);

                Console.WriteLine($"Message published with id {messageID}.");
            }

            keepSendingMessages = GetYesNoResponse("Send another message?", false);
        }
    }

    /// <summary>
    /// Poll for the published messages to see the results of the user's choices.
    /// </summary>
    /// <returns>Async task.</returns>
    public static async Task<List<Message>> PollForMessages(string queueUrl)
    {
        Console.WriteLine(new string('-', 80));
        Console.WriteLine($"Now the SQS queue at {queueUrl} will be polled to retrieve the messages." +
                          "\r\nPress any key to continue.");
        if (UseConsole)
        {
            Console.ReadLine();
        }

        var moreMessages = true;
        var messages = new List<Message>();
        while (moreMessages)
        {
            var newMessages = await SqsWrapper.ReceiveMessagesByUrl(queueUrl, 10);

            moreMessages = newMessages.Any();
            if (moreMessages)
            {
                messages.AddRange(newMessages);
            }
        }

        Console.WriteLine($"{messages.Count} message(s) were received by the queue at {queueUrl}.");

        foreach (var message in messages)
        {
            Console.WriteLine("\tMessage:" +
                              $"\n\t{message.Body}");
        }

        Console.WriteLine(new string('-', 80));
        return messages;
    }

    /// <summary>
    /// Delete the message using handles in a batch.
    /// </summary>
    /// <returns>Async task.</returns>
    public static async Task DeleteMessages(string queueUrl, List<Message> messages)
    {
        Console.WriteLine(new string('-', 80));
        Console.WriteLine("Now we can delete the messages in this queue in a batch.");
        await SqsWrapper.DeleteMessageBatchByUrl(queueUrl, messages);
        Console.WriteLine(new string('-', 80));
    }

    /// <summary>
    /// Clean up the resources from the scenario.
    /// </summary>
    /// <returns>Async task.</returns>
    private static async Task CleanupResources()
    {
        Console.WriteLine(new string('-', 80));
        Console.WriteLine($"Clean up resources.");

        try
        {
            foreach (var queueUrl in _queueUrls)
            {
                if (!string.IsNullOrEmpty(queueUrl))
                {
                    var deleteQueue =
                        GetYesNoResponse($"Delete queue with url {queueUrl}?");
                    if (deleteQueue)
                    {
                        await SqsWrapper.DeleteQueueByUrl(queueUrl);
                    }
                }
            }

            foreach (var subscriptionArn in _subscriptionArns)
            {
                if (!string.IsNullOrEmpty(subscriptionArn))
                {
                    await SnsWrapper.UnsubscribeByArn(subscriptionArn);
                }
            }

            var deleteTopic = GetYesNoResponse($"Delete topic {_topicName}?");
            if (deleteTopic)
            {
                await SnsWrapper.DeleteTopicByArn(_topicArn);
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Unable to clean up resources. Here's why: {ex.Message}.");
        }

        Console.WriteLine(new string('-', 80));
    }

    /// <summary>
    /// Helper method to get a yes or no response from the user.
    /// </summary>
    /// <param name="question">The question string to print on the console.</param>
    /// <param name="defaultAnswer">Optional default answer to use.</param>
    /// <returns>True if the user responds with a yes.</returns>
    private static bool GetYesNoResponse(string question, bool defaultAnswer = true)
    {
        if (UseConsole)
        {
            Console.WriteLine(question);
            var ynResponse = Console.ReadLine();
            var response = ynResponse != null &&
                           ynResponse.Equals("y",
                               StringComparison.InvariantCultureIgnoreCase);
            return response;
        }
        // If not using the console, use the default.
        return defaultAnswer;
    }

    /// <summary>
    /// Helper method to get a string response from the user through the console.
    /// </summary>
    /// <param name="question">The question string to print on the console.</param>
    /// <param name="defaultAnswer">Optional default answer to use.</param>
    /// <returns>True if the user responds with a yes.</returns>
    private static string GetUserResponse(string question, string defaultAnswer)
    {
        if (UseConsole)
        {
            var response = "";
            while (string.IsNullOrEmpty(response))
            {
                Console.WriteLine(question);
                response = Console.ReadLine();
            }
            return response;
        }
        // If not using the console, use the default.
        return defaultAnswer;
    }
}
```
Amazon SQS 작업을 래핑하는 클래스를 만듭니다.  

```
/// <summary>
/// Wrapper for Amazon Simple Queue Service (SQS) operations.
/// </summary>
public class SQSWrapper
{
    private readonly IAmazonSQS _amazonSQSClient;

    /// <summary>
    /// Constructor for the Amazon SQS wrapper.
    /// </summary>
    /// <param name="amazonSQS">The injected Amazon SQS client.</param>
    public SQSWrapper(IAmazonSQS amazonSQS)
    {
        _amazonSQSClient = amazonSQS;
    }

    /// <summary>
    /// Create a queue with a specific name.
    /// </summary>
    /// <param name="queueName">The name for the queue.</param>
    /// <param name="useFifoQueue">True to use a FIFO queue.</param>
    /// <returns>The url for the queue.</returns>
    public async Task<string> CreateQueueWithName(string queueName, bool useFifoQueue)
    {
        int maxMessage = 256 * 1024;
        var queueAttributes = new Dictionary<string, string>
        {
            {
                QueueAttributeName.MaximumMessageSize,
                maxMessage.ToString()
            }
        };

        var createQueueRequest = new CreateQueueRequest()
        {
            QueueName = queueName,
            Attributes = queueAttributes
        };

        if (useFifoQueue)
        {
            // Update the name if it is not correct for a FIFO queue.
            if (!queueName.EndsWith(".fifo"))
            {
                createQueueRequest.QueueName = queueName + ".fifo";
            }

            // Add an attribute for a FIFO queue.
            createQueueRequest.Attributes.Add(
                QueueAttributeName.FifoQueue, "true");
        }

        var createResponse = await _amazonSQSClient.CreateQueueAsync(
            new CreateQueueRequest()
            {
                QueueName = queueName
            });
        return createResponse.QueueUrl;
    }

    /// <summary>
    /// Get the ARN for a queue from its URL.
    /// </summary>
    /// <param name="queueUrl">The URL of the queue.</param>
    /// <returns>The ARN of the queue.</returns>
    public async Task<string> GetQueueArnByUrl(string queueUrl)
    {
        var getAttributesRequest = new GetQueueAttributesRequest()
        {
            QueueUrl = queueUrl,
            AttributeNames = new List<string>() { QueueAttributeName.QueueArn }
        };

        var getAttributesResponse = await _amazonSQSClient.GetQueueAttributesAsync(
            getAttributesRequest);

        return getAttributesResponse.QueueARN;
    }

    /// <summary>
    /// Set the policy attribute of a queue for a topic.
    /// </summary>
    /// <param name="queueArn">The ARN of the queue.</param>
    /// <param name="topicArn">The ARN of the topic.</param>
    /// <param name="queueUrl">The url for the queue.</param>
    /// <returns>True if successful.</returns>
    public async Task<bool> SetQueuePolicyForTopic(string queueArn, string topicArn, string queueUrl)
    {
        var queuePolicy = "{" +
                                "\"Version\": \"2012-10-17\"," +
                                "\"Statement\": [{" +
                                     "\"Effect\": \"Allow\"," +
                                     "\"Principal\": {" +
                                         $"\"Service\": " +
                                             "\"sns.amazonaws.com\"" +
                                            "}," +
                                     "\"Action\": \"sqs:SendMessage\"," +
                                     $"\"Resource\": \"{queueArn}\"," +
                                      "\"Condition\": {" +
                                           "\"ArnEquals\": {" +
                                                $"\"aws:SourceArn\": \"{topicArn}\"" +
                                            "}" +
                                        "}" +
                                "}]" +
                             "}";
        var attributesResponse = await _amazonSQSClient.SetQueueAttributesAsync(
            new SetQueueAttributesRequest()
            {
                QueueUrl = queueUrl,
                Attributes = new Dictionary<string, string>() { { "Policy", queuePolicy } }
            });
        return attributesResponse.HttpStatusCode == HttpStatusCode.OK;
    }

    /// <summary>
    /// Receive messages from a queue by its URL.
    /// </summary>
    /// <param name="queueUrl">The url of the queue.</param>
    /// <returns>The list of messages.</returns>
    public async Task<List<Message>> ReceiveMessagesByUrl(string queueUrl, int maxMessages)
    {
        // Setting WaitTimeSeconds to non-zero enables long polling.
        // For information about long polling, see
        // https://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/sqs-short-and-long-polling.html
        var messageResponse = await _amazonSQSClient.ReceiveMessageAsync(
            new ReceiveMessageRequest()
            {
                QueueUrl = queueUrl,
                MaxNumberOfMessages = maxMessages,
                WaitTimeSeconds = 1
            });
        return messageResponse.Messages;
    }

    /// <summary>
    /// Delete a batch of messages from a queue by its url.
    /// </summary>
    /// <param name="queueUrl">The url of the queue.</param>
    /// <returns>True if successful.</returns>
    public async Task<bool> DeleteMessageBatchByUrl(string queueUrl, List<Message> messages)
    {
        var deleteRequest = new DeleteMessageBatchRequest()
        {
            QueueUrl = queueUrl,
            Entries = new List<DeleteMessageBatchRequestEntry>()
        };
        foreach (var message in messages)
        {
            deleteRequest.Entries.Add(new DeleteMessageBatchRequestEntry()
            {
                ReceiptHandle = message.ReceiptHandle,
                Id = message.MessageId
            });
        }

        var deleteResponse = await _amazonSQSClient.DeleteMessageBatchAsync(deleteRequest);

        return deleteResponse.Failed.Any();
    }

    /// <summary>
    /// Delete a queue by its URL.
    /// </summary>
    /// <param name="queueUrl">The url of the queue.</param>
    /// <returns>True if successful.</returns>
    public async Task<bool> DeleteQueueByUrl(string queueUrl)
    {
        var deleteResponse = await _amazonSQSClient.DeleteQueueAsync(
            new DeleteQueueRequest()
            {
                QueueUrl = queueUrl
            });
        return deleteResponse.HttpStatusCode == HttpStatusCode.OK;
    }
}
```
Amazon SNS 작업을 래핑하는 클래스를 만듭니다.  

```
/// <summary>
/// Wrapper for Amazon Simple Notification Service (SNS) operations.
/// </summary>
public class SNSWrapper
{
    private readonly IAmazonSimpleNotificationService _amazonSNSClient;

    /// <summary>
    /// Constructor for the Amazon SNS wrapper.
    /// </summary>
    /// <param name="amazonSQS">The injected Amazon SNS client.</param>
    public SNSWrapper(IAmazonSimpleNotificationService amazonSNS)
    {
        _amazonSNSClient = amazonSNS;
    }

    /// <summary>
    /// Create a new topic with a name and specific FIFO and de-duplication attributes.
    /// </summary>
    /// <param name="topicName">The name for the topic.</param>
    /// <param name="useFifoTopic">True to use a FIFO topic.</param>
    /// <param name="useContentBasedDeduplication">True to use content-based de-duplication.</param>
    /// <returns>The ARN of the new topic.</returns>
    public async Task<string> CreateTopicWithName(string topicName, bool useFifoTopic, bool useContentBasedDeduplication)
    {
        var createTopicRequest = new CreateTopicRequest()
        {
            Name = topicName,
        };

        if (useFifoTopic)
        {
            // Update the name if it is not correct for a FIFO topic.
            if (!topicName.EndsWith(".fifo"))
            {
                createTopicRequest.Name = topicName + ".fifo";
            }

            // Add the attributes from the method parameters.
            createTopicRequest.Attributes = new Dictionary<string, string>
            {
                { "FifoTopic", "true" }
            };
            if (useContentBasedDeduplication)
            {
                createTopicRequest.Attributes.Add("ContentBasedDeduplication", "true");
            }
        }

        var createResponse = await _amazonSNSClient.CreateTopicAsync(createTopicRequest);
        return createResponse.TopicArn;
    }

    /// <summary>
    /// Subscribe a queue to a topic with optional filters.
    /// </summary>
    /// <param name="topicArn">The ARN of the topic.</param>
    /// <param name="useFifoTopic">The optional filtering policy for the subscription.</param>
    /// <param name="queueArn">The ARN of the queue.</param>
    /// <returns>The ARN of the new subscription.</returns>
    public async Task<string> SubscribeTopicWithFilter(string topicArn, string? filterPolicy, string queueArn)
    {
        var subscribeRequest = new SubscribeRequest()
        {
            TopicArn = topicArn,
            Protocol = "sqs",
            Endpoint = queueArn
        };

        if (!string.IsNullOrEmpty(filterPolicy))
        {
            subscribeRequest.Attributes = new Dictionary<string, string> { { "FilterPolicy", filterPolicy } };
        }

        var subscribeResponse = await _amazonSNSClient.SubscribeAsync(subscribeRequest);
        return subscribeResponse.SubscriptionArn;
    }

    /// <summary>
    /// Publish a message to a topic with an attribute and optional deduplication and group IDs.
    /// </summary>
    /// <param name="topicArn">The ARN of the topic.</param>
    /// <param name="message">The message to publish.</param>
    /// <param name="attributeName">The optional attribute for the message.</param>
    /// <param name="attributeValue">The optional attribute value for the message.</param>
    /// <param name="deduplicationId">The optional deduplication ID for the message.</param>
    /// <param name="groupId">The optional group ID for the message.</param>
    /// <returns>The ID of the message published.</returns>
    public async Task<string> PublishToTopicWithAttribute(
        string topicArn,
        string message,
        string? attributeName = null,
        string? attributeValue = null,
        string? deduplicationId = null,
        string? groupId = null)
    {
        var publishRequest = new PublishRequest()
        {
            TopicArn = topicArn,
            Message = message,
            MessageDeduplicationId = deduplicationId,
            MessageGroupId = groupId
        };

        if (attributeValue != null)
        {
            // Add the string attribute if it exists.
            publishRequest.MessageAttributes =
                new Dictionary<string, MessageAttributeValue>
                {
                    { attributeName!, new MessageAttributeValue() { StringValue = attributeValue, DataType = "String"} }
                };
        }

        var publishResponse = await _amazonSNSClient.PublishAsync(publishRequest);
        return publishResponse.MessageId;
    }


    /// <summary>
    /// Unsubscribe from a topic by a subscription ARN.
    /// </summary>
    /// <param name="subscriptionArn">The ARN of the subscription.</param>
    /// <returns>True if successful.</returns>
    public async Task<bool> UnsubscribeByArn(string subscriptionArn)
    {
        var unsubscribeResponse = await _amazonSNSClient.UnsubscribeAsync(
            new UnsubscribeRequest()
            {
                SubscriptionArn = subscriptionArn
            });
        return unsubscribeResponse.HttpStatusCode == HttpStatusCode.OK;
    }

    /// <summary>
    /// Delete a topic by its topic ARN.
    /// </summary>
    /// <param name="topicArn">The ARN of the topic.</param>
    /// <returns>True if successful.</returns>
    public async Task<bool> DeleteTopicByArn(string topicArn)
    {
        var deleteResponse = await _amazonSNSClient.DeleteTopicAsync(
            new DeleteTopicRequest()
            {
                TopicArn = topicArn
            });
        return deleteResponse.HttpStatusCode == HttpStatusCode.OK;
    }
}
```
+ API 세부 정보는 *AWS SDK for .NET API 참조*의 다음 주제를 참조하세요.
  + [CreateQueue](https://docs.aws.amazon.com/goto/DotNetSDKV3/sqs-2012-11-05/CreateQueue)
  + [CreateTopic](https://docs.aws.amazon.com/goto/DotNetSDKV3/sns-2010-03-31/CreateTopic)
  + [DeleteMessageBatch](https://docs.aws.amazon.com/goto/DotNetSDKV3/sqs-2012-11-05/DeleteMessageBatch)
  + [DeleteQueue](https://docs.aws.amazon.com/goto/DotNetSDKV3/sqs-2012-11-05/DeleteQueue)
  + [DeleteTopic](https://docs.aws.amazon.com/goto/DotNetSDKV3/sns-2010-03-31/DeleteTopic)
  + [GetQueueAttributes](https://docs.aws.amazon.com/goto/DotNetSDKV3/sqs-2012-11-05/GetQueueAttributes)
  + [Publish](https://docs.aws.amazon.com/goto/DotNetSDKV3/sns-2010-03-31/Publish)
  + [ReceiveMessage](https://docs.aws.amazon.com/goto/DotNetSDKV3/sqs-2012-11-05/ReceiveMessage)
  + [SetQueueAttributes](https://docs.aws.amazon.com/goto/DotNetSDKV3/sqs-2012-11-05/SetQueueAttributes)
  + [Subscribe](https://docs.aws.amazon.com/goto/DotNetSDKV3/sns-2010-03-31/Subscribe)
  + [Unsubscribe](https://docs.aws.amazon.com/goto/DotNetSDKV3/sns-2010-03-31/Unsubscribe)

### Amazon SQS에서 .NET용 AWS 메시지 처리 프레임워크 사용
<a name="cross_MessageProcessingFrameworkTutorial_csharp_3_topic"></a>

다음 코드 예제에서는 .NET용 AWS 메시지 처리 프레임워크를 사용하여 Amazon SQS 메시지를 게시하고 수신하는 애플리케이션을 생성하는 방법을 보여줍니다.

**SDK for .NET**  
.NET용 AWS 메시지 처리 프레임워크에 대한 자습서를 제공합니다. 자습서에서는 사용자가 Amazon SQS 메시지와 메시지를 수신하는 명령줄 애플리케이션을 게시할 수 있는 웹 애플리케이션을 생성합니다.  
전체 소스 코드와 설정 및 실행 방법에 대한 지침은 AWS SDK for .NET 개발자 안내서의 [전체 자습서](https://docs.aws.amazon.com/sdk-for-net/latest/developer-guide/msg-proc-fw-get-started.html)와 [GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/cross-service/MessageProcessingFramework)의 예제를 참조하세요.  

**이 예제에서 사용되는 서비스**
+  Amazon SQS

## 서버리스 예제
<a name="serverless_examples"></a>

### Amazon SQS 트리거에서 간접적으로 Lambda 함수 간접 호출
<a name="serverless_SQS_Lambda_csharp_3_topic"></a>

다음 코드 예제는 SQS 대기열에서 메시지를 받아 트리거된 이벤트를 수신하는 Lambda 함수를 구현하는 방법을 보여줍니다. 함수는 이벤트 파라미터에서 메시지를 검색하고 각 메시지의 내용을 로깅합니다.

**SDK for .NET**  
 GitHub에 더 많은 내용이 있습니다. [서버리스 예제](https://github.com/aws-samples/serverless-snippets/tree/main/integration-sqs-to-lambda) 리포지토리에서 전체 예제를 찾아보고 설정 및 실행 방법을 알아봅니다.
.NET을 사용하여 Lambda로 SQS 이벤트 사용  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
using Amazon.Lambda.Core;
using Amazon.Lambda.SQSEvents;


// Assembly attribute to enable the Lambda function's JSON input to be converted into a .NET class.
[assembly: LambdaSerializer(typeof(Amazon.Lambda.Serialization.SystemTextJson.DefaultLambdaJsonSerializer))]

namespace SqsIntegrationSampleCode
{
    public async Task FunctionHandler(SQSEvent evnt, ILambdaContext context)
    {
        foreach (var message in evnt.Records)
        {
            await ProcessMessageAsync(message, context);
        }

        context.Logger.LogInformation("done");
    }

    private async Task ProcessMessageAsync(SQSEvent.SQSMessage message, ILambdaContext context)
    {
        try
        {
            context.Logger.LogInformation($"Processed message {message.Body}");

            // TODO: Do interesting work based on the new message
            await Task.CompletedTask;
        }
        catch (Exception e)
        {
            //You can use Dead Letter Queue to handle failures. By configuring a Lambda DLQ.
            context.Logger.LogError($"An error occurred");
            throw;
        }

    }
}
```

### Amazon SQS 트리거로 Lambda 함수에 대한 배치 항목 실패 보고
<a name="serverless_SQS_Lambda_batch_item_failures_csharp_3_topic"></a>

다음 코드 예제는 SQS 대기열에서 이벤트를 수신하는 Lambda 함수에 대한 부분 배치 응답을 구현하는 방법을 보여줍니다. 이 함수는 응답으로 배치 항목 실패를 보고하고 나중에 해당 메시지를 다시 시도하도록 Lambda에 신호를 보냅니다.

**SDK for .NET**  
 GitHub에 더 많은 내용이 있습니다. [서버리스 예제](https://github.com/aws-samples/serverless-snippets/tree/main/lambda-function-sqs-report-batch-item-failures) 리포지토리에서 전체 예제를 찾아보고 설정 및 실행 방법을 알아봅니다.
.NET을 사용하여 Lambda로 SQS 배치 항목 실패 보고  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
using Amazon.Lambda.Core;
using Amazon.Lambda.SQSEvents;

// Assembly attribute to enable the Lambda function's JSON input to be converted into a .NET class.
[assembly: LambdaSerializer(typeof(Amazon.Lambda.Serialization.SystemTextJson.DefaultLambdaJsonSerializer))]
namespace sqsSample;

public class Function
{
    public async Task<SQSBatchResponse> FunctionHandler(SQSEvent evnt, ILambdaContext context)
    {
        List<SQSBatchResponse.BatchItemFailure> batchItemFailures = new List<SQSBatchResponse.BatchItemFailure>();
        foreach(var message in evnt.Records)
        {
            try
            {
                //process your message
                await ProcessMessageAsync(message, context);
            }
            catch (System.Exception)
            {
                //Add failed message identifier to the batchItemFailures list
                batchItemFailures.Add(new SQSBatchResponse.BatchItemFailure{ItemIdentifier=message.MessageId}); 
            }
        }
        return new SQSBatchResponse(batchItemFailures);
    }

    private async Task ProcessMessageAsync(SQSEvent.SQSMessage message, ILambdaContext context)
    {
        if (String.IsNullOrEmpty(message.Body))
        {
            throw new Exception("No Body in SQS Message.");
        }
        context.Logger.LogInformation($"Processed message {message.Body}");
        // TODO: Do interesting work based on the new message
        await Task.CompletedTask;
    }
}
```