文件 AWS 開發套件範例 GitHub 儲存庫中有更多可用的 [AWS SDK 範例](https://github.com/awsdocs/aws-doc-sdk-examples)。

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。

# `CreatePresignedPost` 搭配 AWS SDK 使用
<a name="s3_example_s3_CreatePresignedPost_section"></a>

以下程式碼範例顯示如何使用 `CreatePresignedPost`。

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#### [ .NET ]

**適用於 .NET 的 SDK (v4)**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv4/S3#code-examples)中設定和執行。
建立預先簽章的 POST URL。  

```
    /// <summary>
    /// Create a presigned POST URL with conditions.
    /// </summary>
    /// <param name="s3Client">The Amazon S3 client.</param>
    /// <param name="bucketName">The name of the bucket.</param>
    /// <param name="objectKey">The object key (path) where the uploaded file will be stored.</param>
    /// <param name="expires">When the presigned URL expires.</param>
    /// <param name="fields">Dictionary of fields to add to the form.</param>
    /// <param name="conditions">List of conditions to apply.</param>
    /// <returns>A CreatePresignedPostResponse object with URL and form fields.</returns>
    public async Task<CreatePresignedPostResponse> CreatePresignedPostAsync(
        IAmazonS3 s3Client,
        string bucketName,
        string objectKey,
        DateTime expires,
        Dictionary<string, string>? fields = null,
        List<S3PostCondition>? conditions = null)
    {
        var request = new CreatePresignedPostRequest
        {
            BucketName = bucketName,
            Key = objectKey,
            Expires = expires
        };

        // Add custom fields if provided
        if (fields != null)
        {
            foreach (var field in fields)
            {
                request.Fields.Add(field.Key, field.Value);
            }
        }

        // Add conditions if provided
        if (conditions != null)
        {
            foreach (var condition in conditions)
            {
                request.Conditions.Add(condition);
            }
        }

        return await s3Client.CreatePresignedPostAsync(request);
    }
```
+  如需 API 詳細資訊，請參閱《*適用於 .NET 的 AWS SDK API 參考*》中的 [CreatePresignedPost](https://docs.aws.amazon.com/goto/DotNetSDKV4/s3-2006-03-01/CreatePresignedPost)。

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