如何将图像作为 asp.net web api 中的参数上传到 Amazon S3

Question

我需要将图像上传到 Amazon S3，它将作为来自前端的参数

我正在考虑获取图像的路径并从路径中获取图像，如下所述：

    [HttpPost]
    [Route("upload")]
    public HttpResponseMessage UploadImage(string localImagePath)
    {
      Image img = Image.FromFile(localImagePath);

      // performing the image upload to S3
    }

但是前端人员将图像作为文件发送。发送图片的格式应该是什么？

谁能帮我在asp.net WEB API中上传图片。

Answer 1

请要求前端人员将文件作为多部分内容发送。

参考下面的代码来做你的事：

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);
        }
    }
}

您可以从这里参考更多信息：Amazon S3 File Upload