aws-sdk-net

在开始之前，您必须生成 Access Key。所有示例都将使用 access_key_id 和 access_key_secret 变量，分别代表您生成的 Access Key ID（访问密钥 ID） 和 Secret Access Key（秘密访问密钥） 值。

本示例使用 aws-sdk-net ↗ 包的第 3 版。实例化 S3 服务客户端时，必须传入 R2 配置凭据：

客户端设置

在本示例中，您将在 IAmazonS3 初始化时显式传入凭据。如果需要，可以与其他 AWS SDK 一样使用共享 AWS 凭据文件或 SDK 存储。有关更多详情，请参阅配置 AWS 凭据 ↗。

private static IAmazonS3 s3Client;

public static void Main(string[] args)
{
	// Retrieve your S3 API credentials for your R2 bucket via API tokens (see: https://developers.cloudflare.com/r2/api/tokens)
	var accessKey = "<ACCESS_KEY_ID>";
	var secretKey = "<SECRET_ACCESS_KEY>";
	var credentials = new BasicAWSCredentials(accessKey, secretKey);
	s3Client = new AmazonS3Client(credentials, new AmazonS3Config
		{
			// Provide your Cloudflare account ID
			ServiceURL = "https://<ACCOUNT_ID>.r2.cloudflarestorage.com",
		});
}

列出存储桶和对象

ListBucketsAsync ↗ 和 ListObjectsAsync ↗ 方法可用于分别列出账户下的存储桶以及这些存储桶中的内容。

static async Task ListBuckets()
{
	var response = await s3Client.ListBucketsAsync();

	foreach (var s3Bucket in response.Buckets)
	{
		Console.WriteLine("{0}", s3Bucket.BucketName);
	}
}

sdk-example
my-bucket

static async Task ListObjectsV2()
{
	var request = new ListObjectsV2Request
	{
		BucketName = "my-bucket"
	};

	var response = await s3Client.ListObjectsV2Async(request);

	foreach (var s3Object in response.S3Objects)
	{
		Console.WriteLine("{0}", s3Object.Key);
	}
}

dog.png
cat.png

上传和获取对象

PutObjectAsync ↗ 和 GetObjectAsync ↗ 方法可用于分别向 R2 存储桶上传对象和从 R2 存储桶下载对象。

static async Task PutObject()
{
	var request = new PutObjectRequest
	{
		FilePath = @"/path/file.txt",
		BucketName = "my-bucket",
		DisablePayloadSigning = true,
		DisableDefaultChecksumValidation = true
	};

	var response = await s3Client.PutObjectAsync(request);

	Console.WriteLine("ETag: {0}", response.ETag);
}

ETag: "186a71ee365d9686c3b98b6976e1f196"

static async Task GetObject()
{
	var bucket = "my-bucket";
	var key = "file.txt";

	var response = await s3Client.GetObjectAsync(bucket, key);

	Console.WriteLine("ETag: {0}", response.ETag);
}

ETag: "186a71ee365d9686c3b98b6976e1f196"

生成预签名 URL

GetPreSignedURL ↗ 方法允许您预先签名，为特定操作授予临时访问权限。在本例中，为 sdk-example/file.txt 预签名 PutObject 请求。

static string? GeneratePresignedUrl()
{
	AWSConfigsS3.UseSignatureVersion4 = true;
	var presign = new GetPreSignedUrlRequest
	{
		BucketName = "my-bucket",
		Key = "file.txt",
		Verb = HttpVerb.GET,
		Expires = DateTime.Now.AddDays(7),
	};

	var presignedUrl = s3Client.GetPreSignedURL(presign);

	Console.WriteLine(presignedUrl);

	return presignedUrl;
}

https://<ACCOUNT_ID>.r2.cloudflarestorage.com/my-bucket/file.txt?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=<credential>&X-Amz-Date=<timestamp>&X-Amz-Expires=3600&X-Amz-SignedHeaders=host&X-Amz-Signature=<signature>