Amazon Simple Storage Service
Developer Guide (API Version 2006-03-01)

Upload a File to an S3 Bucket Using the AWS SDK for .NET (Low-Level API)

The following C# example shows how to use the low-level AWS SDK for .NET multipart upload API to upload a file to an S3 bucket. For information about Amazon S3 multipart uploads, see Multipart Upload Overview.


When you use the AWS SDK for .NET API to upload large objects, a timeout might occur while data is being written to the request stream. You can set an explicit timeout using the UploadPartRequest.

The following C# example uploads a file to an S3 bucket using the low-level multipart upload API. For information about the example's compatibility with a specific version of the AWS SDK for .NET and instructions for creating and testing a working sample, see Running the Amazon S3 .NET Code Examples.

// Copyright 2018, Inc. or its affiliates. All Rights Reserved. // SPDX-License-Identifier: MIT-0 (For details, see using Amazon.Runtime; using Amazon.S3; using Amazon.S3.Model; using System; using System.Collections.Generic; using System.IO; using System.Threading.Tasks; namespace Amazon.DocSamples.S3 { class UploadFileMPULowLevelAPITest { private const string bucketName = "*** provide bucket name ***"; private const string keyName = "*** provide a name for the uploaded object ***"; private const string filePath = "*** provide the full path name of the file to upload ***"; // Specify your bucket region (an example region is shown). private static readonly RegionEndpoint bucketRegion = RegionEndpoint.USWest2; private static IAmazonS3 s3Client; public static void Main() { s3Client = new AmazonS3Client(bucketRegion); Console.WriteLine("Uploading an object"); UploadObjectAsync().Wait(); } private static async Task UploadObjectAsync() { // Create list to store upload part responses. List<UploadPartResponse> uploadResponses = new List<UploadPartResponse>(); // Setup information required to initiate the multipart upload. InitiateMultipartUploadRequest initiateRequest = new InitiateMultipartUploadRequest { BucketName = bucketName, Key = keyName }; // Initiate the upload. InitiateMultipartUploadResponse initResponse = await s3Client.InitiateMultipartUploadAsync(initiateRequest); // Upload parts. long contentLength = new FileInfo(filePath).Length; long partSize = 5 * (long)Math.Pow(2, 20); // 5 MB try { Console.WriteLine("Uploading parts"); long filePosition = 0; for (int i = 1; filePosition < contentLength; i++) { UploadPartRequest uploadRequest = new UploadPartRequest { BucketName = bucketName, Key = keyName, UploadId = initResponse.UploadId, PartNumber = i, PartSize = partSize, FilePosition = filePosition, FilePath = filePath }; // Track upload progress. uploadRequest.StreamTransferProgress += new EventHandler<StreamTransferProgressArgs>(UploadPartProgressEventCallback); // Upload a part and add the response to our list. uploadResponses.Add(await s3Client.UploadPartAsync(uploadRequest)); filePosition += partSize; } // Setup to complete the upload. CompleteMultipartUploadRequest completeRequest = new CompleteMultipartUploadRequest { BucketName = bucketName, Key = keyName, UploadId = initResponse.UploadId }; completeRequest.AddPartETags(uploadResponses); // Complete the upload. CompleteMultipartUploadResponse completeUploadResponse = await s3Client.CompleteMultipartUploadAsync(completeRequest); } catch (Exception exception) { Console.WriteLine("An AmazonS3Exception was thrown: { 0}", exception.Message); // Abort the upload. AbortMultipartUploadRequest abortMPURequest = new AbortMultipartUploadRequest { BucketName = bucketName, Key = keyName, UploadId = initResponse.UploadId }; await s3Client.AbortMultipartUploadAsync(abortMPURequest); } } public static void UploadPartProgressEventCallback(object sender, StreamTransferProgressArgs e) { // Process event. Console.WriteLine("{0}/{1}", e.TransferredBytes, e.TotalBytes); } } }

More Info


On this page: