通过Web API ASP.NET Framework Web应用程序C＃将图像/文件上传到Blob Azure

如何解决通过Web API ASP.NET Framework Web应用程序C＃将图像/文件上传到Blob Azure

在尝试将图片上传到blob时使用邮递员测试api时获得http 400：

 [Route("~/api/myAPI/testapi")]
 [HttpPost]
 public async Task<HttpResponseMessage> testapi()
 {
     String strorageconn = System.Configuration.ConfigurationManager.AppSettings.Get("MyBlobStorageConnectionString");
     Dictionary<string,object> dict = new Dictionary<string,object>(); 

     try  
     {  
         // Create a CloudStorageAccount object using account name and key.
         // The account name should be just the name of a Storage Account,not a URI,and 
         // not including the suffix. The key should be a base-64 encoded string that you
         // can acquire from the portal,or from the management plane.
         // This will have full permissions to all operations on the account.
        // StorageCredentials storageCredentials = new StorageCredentials(myAccountName,myAccountKey);
         //CloudStorageAccount cloudStorageAccount = new CloudStorageAccount(storageCredentials,useHttps: true);
         // Parse the connection string and return a reference to the storage account.
         CloudStorageAccount storageAccount = CloudStorageAccount.Parse(strorageconn);
            
         // If the connection string is valid,proceed with operations against Blob
         // storage here.
         // ADD OTHER OPERATIONS HERE
         // Create the CloudBlobClient that represents the 
         // Blob storage endpoint for the storage account.
         CloudBlobClient cloudBlobClient = storageAccount.CreateCloudBlobClient();
         // Create a container called 'quickstartblobs' and 
         // append a GUID value to it to make the name unique.
         CloudBlobContainer cloudBlobContainer = cloudBlobClient.GetContainerReference("images"); 
         //"quickstartblobs" + Guid.NewGuid().ToString());
         await cloudBlobContainer.CreateAsync();
         if (cloudBlobContainer.CreateIfNotExists())
         {
             cloudBlobContainer.SetPermissions(
                 new BlobContainerPermissions
                 {
                     PublicAccess = BlobContainerPublicAccessType.Blob
                 });
         }
         // Set the permissions so the blobs are public.
        /* BlobContainerPermissions permissions = new BlobContainerPermissions
         {
             PublicAccess = BlobContainerPublicAccessType.Blob
         };
         await cloudBlobContainer.SetPermissionsAsync(permissions); */
            
             // Create a CloudBlobClient object from the storage account.
             // This object is the root object for all operations on the 
             // blob service for this particular account.
             //CloudBlobClient blobClient = cloudStorageAccount.CreateCloudBlobClient();
             var httpRequest = HttpContext.Current.Request;         
             foreach (string file in httpRequest.Files)  
             {  
                 HttpResponseMessage response = Request.CreateResponse(HttpStatusCode.Created);  

                 var postedFile = httpRequest.Files[file]; 
                 // Get a reference to a CloudBlobContainer object in this account. 
                 // This object can be used to create the container on the service,// list blobs,delete the container,etc. This operation does not make a 
                 // call to the Azure Storage service.  It neither creates the container 
                 // on the service,nor validates its existence.
                 string imageName = "images" +serverTime.Year.ToString() + serverTime.Month.ToString() + serverTime.Day.ToString() + 
                                             serverTime.Hour.ToString() + serverTime.Minute.ToString() + serverTime.Second.ToString () 
                                             + postedFile.FileName.ToLower();
                 //CloudBlobContainer container = blobClient.GetContainerReference(imageName.ToLower());
                 /*if(await container.CreateIfNotExistsAsync())  
                 {  
                     await container.SetPermissionsAsync(  
                         new BlobContainerPermissions {  
                             PublicAccess = BlobContainerPublicAccessType.Blob  
                         }  
                         );  
                 }  */

                 if (postedFile != null && postedFile.ContentLength > 0)  
                 {  

                     int MaxContentLength = 1024 * 1024 * 1; //Size = 1 MB  

                     IList<string> AllowedFileExtensions = new List<string> { ".jpg",".gif",".png" };  
                     var ext = postedFile.FileName.Substring(postedFile.FileName.LastIndexOf('.'));  
                     var extension = ext.ToLower();  
                     if (!AllowedFileExtensions.Contains(extension))  
                     {  

                         var message = string.Format("Please Upload image of type .jpg,.gif,.png.");  

                         dict.Add("error",message);  
                         return Request.CreateResponse(HttpStatusCode.BadRequest,dict);  
                     }  
                     else if (postedFile.ContentLength > MaxContentLength)  
                     {  

                         var message = string.Format("Please Upload a file upto 1 mb.");  

                         dict.Add("error",dict);  
                     }  
                     else  
                     {  

                         

                         var filePath = HttpContext.Current.Server.MapPath("~/imagesfiles/uploads" + postedFile.FileName.ToLower() + extension.ToLower());  
                        
                         postedFile.SaveAs(filePath);  
                         //CloudBlockBlob cloudBlockBlob = container.GetBlockBlobReference(imageName);  
                         // Get a reference to the blob address,then upload the file to the blob.
                         // Use the value of localFileName for the blob name.
                         CloudBlockBlob cloudBlockBlob = cloudBlobContainer.GetBlockBlobReference(imageName.ToLower());
                        
                          // create a blob in container and upload image bytes to it
                         //var blob =container.GetBlobReference(postedFile.FileName);
                         await cloudBlockBlob.UploadFromFileAsync(postedFile.FileName);
                         //await cloudBlockBlob.UploadFromFileAsync(filePath); 

                     }  
                 }
                 var message1 = string.Format("Image Updated Successfully.");
                 return Request.CreateErrorResponse(HttpStatusCode.Created,message1); ;
             }
            
           
             var res = string.Format("Please Upload a image.");
             dict.Add("error",res);
             return Request.CreateResponse(HttpStatusCode.NotFound,dict);
            
     }  
     catch (Exception ex)  
     {
         HttpResponseMessage response2 = Request.CreateResponse(HttpStatusCode.BadRequest,ex.InnerException.ToString());
         return response2;
     }  
 }

邮递员的回复：

"System.Net.WebException: The remote server returned an error: (400) Bad Request.\r\n at Microsoft.Azure.Storage.Shared.Protocol.HttpResponseParsers.ProcessExpectedStatusCodeNoException[T](HttpStatusCode expectedStatusCode,HttpStatusCode actualStatusCode,T retVal,StorageCommandBase`1 cmd,Exception ex)\r\n at Microsoft.Azure.Storage.Blob.CloudBlobContainer.<>c_DisplayClass149_0.<CreateContainerImpl>b_2(RESTCommand`1 cmd,HttpWebResponse resp,Exception ex,OperationContext ctx)\r\n at Microsoft.Azure.Storage.Core.Executor.Executor.EndGetResponse[T](IAsyncResult getResponseResult)"

解决方法

感谢彭美拉（Pamela Peng），我得以面对不同的异常并找到了问题。

第一个问题是版本，因此我更改为Visual Studio 2019，必须添加正确的参考。而另一个问题在代码中，所以我用：

                        else
                        {
                            CloudBlockBlob cloudBlockBlob = cloudBlobContainer.GetBlockBlobReference(imageName);
                            cloudBlockBlob.Properties.ContentType = postedFile.ContentType;
                            await cloudBlockBlob.UploadFromStreamAsync(postedFile.InputStream);
                        } 

,

不确定为什么它不起作用，代码看起来正确。在许多情况下都会发生此错误。

1. 如果您请求的容器名称无效，将导致您收到（400）错误的请求。它有一些关于容器名称的limitations，因此请检查您的字符串。

2. 如果Blob存储模拟器无法启动，它将返回400 Bad Request。参见here。

3. 如果存储库和存储仿真器的版本不同步，它还将返回400 Bad Request，请参见here。

4. 最后，您的存储位置可能很重要，请参阅here。