C＃HttpClient 4.5 multipart/form-data upload

Question

有谁知道如何使用.net 4.5中的HttpClient与multipart/form-data上传？

我在互联网上找不到任何示例。

async public Task<HttpResponseMessage> UploadImage(string url, byte[] ImageData) 
{ 
    var requestContent = new MultipartFormDataContent(); 
    // here you can specify boundary if you need---^ 
    var imageContent = new ByteArrayContent(ImageData); 
    imageContent.Headers.ContentType = 
     MediaTypeHeaderValue.Parse("image/jpeg"); 

    requestContent.Add(imageContent, "image", "image.jpg"); 

    return await client.PostAsync(url, requestContent); 
} 

（您可以requestContent.Add()任何你想要的，看看在HttpContent descendant以查看可用的类型传递）：

Answer 1

我的结果是这样的：

public static async Task<string> Upload(byte[] image) 
{ 
    using (var client = new HttpClient()) 
    { 
     using (var content = 
      new MultipartFormDataContent("Upload----" + DateTime.Now.ToString(CultureInfo.InvariantCulture))) 
     { 
      content.Add(new StreamContent(new MemoryStream(image)), "bilddatei", "upload.jpg"); 

       using (
       var message = 
        await client.PostAsync("http://www.directupload.net/index.php?mode=upload", content)) 
       { 
        var input = await message.Content.ReadAsStringAsync(); 

        return !string.IsNullOrWhiteSpace(input) ? Regex.Match(input, @"http://\w*\.directupload\.net/images/\d*/\w*\.[a-z]{3}").Value : null; 
       } 
      } 
    } 
} 

Answer 2

它（使用图像/ JPG文件的例子）的作品或多或少像这样

完成后，您会在HttpResponseMessage.Content内找到您可以通过HttpContent.ReadAs*Async消费的响应内容。

Answer 3

这是如何使用MultipartFormDataContent发布的HTTPClient字符串和文件流的例子。 Content-Disposition和Content-Type需要为每个HTTPContent指定：

这是我的例子。希望它有帮助：

private static void Upload() 
{ 
    using (var client = new HttpClient()) 
    { 
     client.DefaultRequestHeaders.Add("User-Agent", "CBS Brightcove API Service"); 

     using (var content = new MultipartFormDataContent()) 
     { 
      var path = @"C:\B2BAssetRoot\files\596086\596086.1.mp4"; 

      string assetName = Path.GetFileName(path); 

      var request = new HTTPBrightCoveRequest() 
       { 
        Method = "create_video", 
        Parameters = new Params() 
         { 
          CreateMultipleRenditions = "true", 
          EncodeTo = EncodeTo.Mp4.ToString().ToUpper(), 
          Token = "x8sLalfXacgn-4CzhTBm7uaCxVAPjvKqTf1oXpwLVYYoCkejZUsYtg..", 
          Video = new Video() 
           { 
            Name = assetName, 
            ReferenceId = Guid.NewGuid().ToString(), 
            ShortDescription = assetName 
           } 
         } 
       }; 

      //Content-Disposition: form-data; name="json" 
      var stringContent = new StringContent(JsonConvert.SerializeObject(request)); 
      stringContent.Headers.Add("Content-Disposition", "form-data; name=\"json\""); 
      content.Add(stringContent, "json"); 

      FileStream fs = File.OpenRead(path); 

      var streamContent = new StreamContent(fs); 
      streamContent.Headers.Add("Content-Type", "application/octet-stream"); 
      //Content-Disposition: form-data; name="file"; filename="C:\B2BAssetRoot\files\596090\596090.1.mp4"; 
      streamContent.Headers.Add("Content-Disposition", "form-data; name=\"file\"; filename=\"" + Path.GetFileName(path) + "\""); 
      content.Add(streamContent, "file", Path.GetFileName(path)); 

      //content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment"); 

      Task<HttpResponseMessage> message = client.PostAsync("http://api.brightcove.com/services/post", content); 

      var input = message.Result.Content.ReadAsStringAsync(); 
      Console.WriteLine(input.Result); 
      Console.Read(); 
     } 
    } 
} 

Answer 4

这是一个完整的示例，为我工作。 .NET中自动添加请求中的boundary值。

var url = "http://localhost/api/v1/yourendpointhere"; 
var filePath = @"C:\path\to\image.jpg"; 

HttpClient httpClient = new HttpClient(); 
MultipartFormDataContent form = new MultipartFormDataContent(); 

FileStream fs = File.OpenRead(filePath); 
var streamContent = new StreamContent(fs); 

var imageContent = new ByteArrayContent(streamContent.ReadAsByteArrayAsync().Result); 
imageContent.Headers.ContentType = MediaTypeHeaderValue.Parse("multipart/form-data"); 

form.Add(imageContent, "image", Path.GetFileName(filePath)); 
var response = httpClient.PostAsync(url, form).Result;