本文為英文版的機器翻譯版本，如內容有任何歧義或不一致之處，概以英文版為準。

# 使用 CloudWatch 警示
<a name="examples-cloudwatch-create-alarms"></a>

## 先決條件
<a name="codeExamplePrereq"></a>

開始之前，建議您先閱讀[開始使用 適用於 C\$1\$1 的 AWS SDK](getting-started.md)。

下載範例程式碼並建置解決方案，如中所述[程式碼範例入門](getting-started-code-examples.md)。

若要執行範例，您的程式碼用來提出請求的使用者描述檔必須具有 AWS （針對 服務和 動作） 的適當許可。如需詳細資訊，請參閱[提供 AWS 登入](credentials.md)資料。

## 建立警示
<a name="create-an-alarm"></a>

若要根據 CloudWatch 指標建立警示，請呼叫 CloudWatchClient 的 `PutMetricAlarm`函數，並將 [PutMetricAlarmRequest](https://docs.aws.amazon.com/sdk-for-cpp/latest/api/aws-cpp-sdk-monitoring/html/class_aws_1_1_cloud_watch_1_1_model_1_1_put_metric_alarm_request.html) 填入警示條件。

 **包括** 

```
#include <aws/core/Aws.h>
#include <aws/monitoring/CloudWatchClient.h>
#include <aws/monitoring/model/PutMetricAlarmRequest.h>
#include <iostream>
```

 **Code** 

```
        Aws::CloudWatch::CloudWatchClient cw;
        Aws::CloudWatch::Model::PutMetricAlarmRequest request;
        request.SetAlarmName(alarm_name);
        request.SetComparisonOperator(
            Aws::CloudWatch::Model::ComparisonOperator::GreaterThanThreshold);
        request.SetEvaluationPeriods(1);
        request.SetMetricName("CPUUtilization");
        request.SetNamespace("AWS/EC2");
        request.SetPeriod(60);
        request.SetStatistic(Aws::CloudWatch::Model::Statistic::Average);
        request.SetThreshold(70.0);
        request.SetActionsEnabled(false);
        request.SetAlarmDescription("Alarm when server CPU exceeds 70%");
        request.SetUnit(Aws::CloudWatch::Model::StandardUnit::Seconds);

        Aws::CloudWatch::Model::Dimension dimension;
        dimension.SetName("InstanceId");
        dimension.SetValue(instanceId);

        request.AddDimensions(dimension);

        auto outcome = cw.PutMetricAlarm(request);
        if (!outcome.IsSuccess())
        {
            std::cout << "Failed to create CloudWatch alarm:" <<
                outcome.GetError().GetMessage() << std::endl;
        }
        else
        {
            std::cout << "Successfully created CloudWatch alarm " << alarm_name
                << std::endl;
        }
```

請參閱[完整範例](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/cloudwatch/put_metric_alarm.cpp)。

## 列出警示
<a name="list-alarms"></a>

若要列出您已建立的 CloudWatch 警示，請使用 [DescribeAlarmsRequest](https://docs.aws.amazon.com/sdk-for-cpp/latest/api/aws-cpp-sdk-monitoring/html/class_aws_1_1_cloud_watch_1_1_model_1_1_describe_alarms_request.html) 呼叫 CloudWatchClient 的 `DescribeAlarms`函數，以用於設定結果的選項。

 **包括** 

```
#include <aws/core/Aws.h>
#include <aws/monitoring/CloudWatchClient.h>
#include <aws/monitoring/model/DescribeAlarmsRequest.h>
#include <aws/monitoring/model/DescribeAlarmsResult.h>
#include <iomanip>
#include <iostream>
```

 **Code** 

```
        Aws::CloudWatch::CloudWatchClient cw;
        Aws::CloudWatch::Model::DescribeAlarmsRequest request;
        request.SetMaxRecords(1);

        bool done = false;
        bool header = false;
        while (!done)
        {
            auto outcome = cw.DescribeAlarms(request);
            if (!outcome.IsSuccess())
            {
                std::cout << "Failed to describe CloudWatch alarms:" <<
                    outcome.GetError().GetMessage() << std::endl;
                break;
            }

            if (!header)
            {
                std::cout << std::left <<
                    std::setw(32) << "Name" <<
                    std::setw(64) << "Arn" <<
                    std::setw(64) << "Description" <<
                    std::setw(20) << "LastUpdated" <<
                    std::endl;
                header = true;
            }

            const auto &alarms = outcome.GetResult().GetMetricAlarms();
            for (const auto &alarm : alarms)
            {
                std::cout << std::left <<
                    std::setw(32) << alarm.GetAlarmName() <<
                    std::setw(64) << alarm.GetAlarmArn() <<
                    std::setw(64) << alarm.GetAlarmDescription() <<
                    std::setw(20) <<
                    alarm.GetAlarmConfigurationUpdatedTimestamp().ToGmtString(
                        SIMPLE_DATE_FORMAT_STR) <<
                    std::endl;
            }

            const auto &next_token = outcome.GetResult().GetNextToken();
            request.SetNextToken(next_token);
            done = next_token.empty();
        }
```

您可以在 傳回的 [DescribeAlarmsResult](https://docs.aws.amazon.com/sdk-for-cpp/latest/api/aws-cpp-sdk-monitoring/html/class_aws_1_1_cloud_watch_1_1_model_1_1_describe_alarms_result.html) `getMetricAlarms`上呼叫 ，以取得警示清單`DescribeAlarms`。

結果可能會*分頁*。若要擷取下一批結果，`SetNextToken`請使用`DescribeAlarmsResult`物件`GetNextToken`函數的傳回值呼叫原始請求物件，並將修改後的請求物件傳回給另一個 呼叫`DescribeAlarms`。

**注意**  
您也可以使用 CloudWatchClient 的 `DescribeAlarmsForMetric`函數來擷取特定指標的警示。其用法類似於 `DescribeAlarms`。

請參閱[完整範例](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/cloudwatch/describe_alarms.cpp)。

## 刪除警示
<a name="delete-alarms"></a>

若要刪除 CloudWatch 警示，請使用 [DeleteAlarmsRequest](https://docs.aws.amazon.com/sdk-for-cpp/latest/api/aws-cpp-sdk-monitoring/html/class_aws_1_1_cloud_watch_1_1_model_1_1_delete_alarms_request.html) 呼叫 CloudWatchClient 的`DeleteAlarms`函數，其中包含您想要刪除的一或多個警示名稱。

 **包括** 

```
#include <aws/core/Aws.h>
#include <aws/monitoring/CloudWatchClient.h>
#include <aws/monitoring/model/DeleteAlarmsRequest.h>
#include <iostream>
```

 **Code** 

```
        Aws::CloudWatch::CloudWatchClient cw;
        Aws::CloudWatch::Model::DeleteAlarmsRequest request;
        request.AddAlarmNames(alarm_name);

        auto outcome = cw.DeleteAlarms(request);
        if (!outcome.IsSuccess())
        {
            std::cout << "Failed to delete CloudWatch alarm:" <<
                outcome.GetError().GetMessage() << std::endl;
        }
        else
        {
            std::cout << "Successfully deleted CloudWatch alarm " << alarm_name
                << std::endl;
        }
```

請參閱[完整範例](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/cloudwatch/delete_alarm.cpp)。

## 詳細資訊
<a name="more-information"></a>
+  《[Amazon CloudWatch 使用者指南》中的建立 Amazon CloudWatch 警示](https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/AlarmThatSendsEmail.html) Amazon CloudWatch 
+  Amazon CloudWatch API 參考中的 [PutMetricAlarm](https://docs.aws.amazon.com/AmazonCloudWatch/latest/APIReference/PutMetricAlarm.html) 
+  Amazon CloudWatch API 參考中的 [DescribeAlarms](https://docs.aws.amazon.com/AmazonCloudWatch/latest/APIReference/DescribeAlarms.html) 
+  Amazon CloudWatch API 參考中的 [DeleteAlarms](https://docs.aws.amazon.com/AmazonCloudWatch/latest/APIReference/DeleteAlarms.html)