C# HttpClient 4.5 multipart/form-data 上传

C# HttpClient 4.5 multipart/form-data upload

提问by ident

Does anyone know how to use the HttpClientin .Net 4.5 with multipart/form-dataupload?

有谁知道如何HttpClient在 .Net 4.5 中使用multipart/form-data上传？

I couldn't find any examples on the internet.

我在互联网上找不到任何示例。

采纳答案by ident

my result looks like this:

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;
              }
          }
     }
}

回答by WDRust

It works more or less like this (example using an image/jpg file):

它的工作方式或多或少是这样的（使用图像/jpg 文件的示例）：

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);
}

(You can requestContent.Add()whatever you want, take a look at the HttpContent descendantto see available types to pass in)

（您可以requestContent.Add()随心所欲，查看HttpContent 后代以查看要传入的可用类型）

When completed, you'll find the response content inside HttpResponseMessage.Contentthat you can consume with HttpContent.ReadAs*Async.

完成后，您会在其中找到HttpResponseMessage.Content可以使用的响应内容HttpContent.ReadAs*Async。

回答by Johnny Chu

This is an example of how to post string and file stream with HTTPClient using MultipartFormDataContent. The Content-Disposition and Content-Type need to be specified for each HTTPContent:

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

Here's my example. Hope it helps:

这是我的例子。希望能帮助到你：

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\files60866086.1.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\files60906090.1.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();
        }
    }
}

回答by nthpixel

Here's a complete sample that worked for me. The boundaryvalue in the request is added automatically by .NET.

这是一个对我有用的完整示例。boundary请求中的值由 .NET 自动添加。

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;

回答by Vishnu Kumar

Try this its working for me.

试试这个对我有用。

private static async Task<object> Upload(string actionUrl)
{
    Image newImage = Image.FromFile(@"Absolute Path of image");
    ImageConverter _imageConverter = new ImageConverter();
    byte[] paramFileStream= (byte[])_imageConverter.ConvertTo(newImage, typeof(byte[]));

    var formContent = new MultipartFormDataContent
    {
        // Send form text values here
        {new StringContent("value1"),"key1"},
        {new StringContent("value2"),"key2" },
        // Send Image Here
        {new StreamContent(new MemoryStream(paramFileStream)),"imagekey","filename.jpg"}
    };

    var myHttpClient = new HttpClient();
    var response = await myHttpClient.PostAsync(actionUrl.ToString(), formContent);
    string stringContent = await response.Content.ReadAsStringAsync();

    return response;
}

回答by Erik Kalkoken

Here is another example on how to use HttpClientto upload a multipart/form-data.

这是另一个关于如何使用HttpClient上传multipart/form-data.

It uploads a file to a REST API and includes the file itself (e.g. a JPG) and additional API parameters. The file is directly uploaded from local disk via FileStream.

它将文件上传到 REST API 并包含文件本身（例如 JPG）和其他 API 参数。文件直接从本地磁盘通过FileStream.

See herefor the full example including additional API specific logic.

有关完整示例，请参见此处，包括其他 API 特定逻辑。

public static async Task UploadFileAsync(string token, string path, string channels)
{
    // we need to send a request with multipart/form-data
    var multiForm = new MultipartFormDataContent();

    // add API method parameters
    multiForm.Add(new StringContent(token), "token");
    multiForm.Add(new StringContent(channels), "channels");

    // add file and directly upload it
    FileStream fs = File.OpenRead(path);
    multiForm.Add(new StreamContent(fs), "file", Path.GetFileName(path));

    // send request to API
    var url = "https://slack.com/api/files.upload";
    var response = await client.PostAsync(url, multiForm);
}

回答by Hyman The Ripper

public async Task<object> PassImageWithText(IFormFile files)
{
    byte[] data;
    string result = "";
    ByteArrayContent bytes;

    MultipartFormDataContent multiForm = new MultipartFormDataContent();

    try
    {
        using (var client = new HttpClient())
        {
            using (var br = new BinaryReader(files.OpenReadStream()))
            {
                data = br.ReadBytes((int)files.OpenReadStream().Length);
            }

            bytes = new ByteArrayContent(data);
            multiForm.Add(bytes, "files", files.FileName);
            multiForm.Add(new StringContent("value1"), "key1");
            multiForm.Add(new StringContent("value2"), "key2");

            var res = await client.PostAsync(_MEDIA_ADD_IMG_URL, multiForm);
        }
    }
    catch (Exception e)
    {
        throw new Exception(e.ToString());
    }

    return result;
}

回答by Rajenthiran T

X509Certificate clientKey1 = null;
clientKey1 = new X509Certificate(AppSetting["certificatePath"],
AppSetting["pswd"]);
string url = "https://EndPointAddress";
FileStream fs = File.OpenRead(FilePath);
var streamContent = new StreamContent(fs);

var FileContent = new ByteArrayContent(streamContent.ReadAsByteArrayAsync().Result);
FileContent.Headers.ContentType = MediaTypeHeaderValue.Parse("ContentType");
var handler = new WebRequestHandler();


handler.ClientCertificateOptions = ClientCertificateOption.Manual;
handler.ClientCertificates.Add(clientKey1);
handler.ServerCertificateValidationCallback = (httpRequestMessage, cert, cetChain, policyErrors) =>
{
    return true;
};


using (var client = new HttpClient(handler))
{
    // Post it
    HttpResponseMessage httpResponseMessage = client.PostAsync(url, FileContent).Result;

    if (!httpResponseMessage.IsSuccessStatusCode)
    {
        string ss = httpResponseMessage.StatusCode.ToString();
    }
}

回答by RBT

I'm adding a code snippet which shows on how to post a file to an API which has been exposed over DELETE http verb. This is not a common case to upload a file with DELETE http verb but it is allowed. I've assumed Windows NTLM authentication for authorizing the call.

我正在添加一个代码片段，它显示了如何将文件发布到已通过 DELETE http 动词公开的 API。这不是上传带有 DELETE http 动词的文件的常见情况，但这是允许的。我假设使用 Windows NTLM 身份验证来授权调用。

The problem that one might face is that all the overloads of HttpClient.DeleteAsyncmethod have no parameters for HttpContentthe way we get it in PostAsyncmethod

人们可能面临的问题是HttpClient.DeleteAsync方法的所有重载都没有HttpContent我们在PostAsync方法中获取它的方式的参数

var requestUri = new Uri("http://UrlOfTheApi");
using (var streamToPost = new MemoryStream("C:\temp.txt"))
using (var fileStreamContent = new StreamContent(streamToPost))
using (var httpClientHandler = new HttpClientHandler() { UseDefaultCredentials = true })
using (var httpClient = new HttpClient(httpClientHandler, true))
using (var requestMessage = new HttpRequestMessage(HttpMethod.Delete, requestUri))
using (var formDataContent = new MultipartFormDataContent())
{
    formDataContent.Add(fileStreamContent, "myFile", "temp.txt");
    requestMessage.Content = formDataContent;
    var response = httpClient.SendAsync(requestMessage).GetAwaiter().GetResult();

    if (response.IsSuccessStatusCode)
    {
        // File upload was successfull
    }
    else
    {
        var erroResult = response.Content.ReadAsStringAsync().GetAwaiter().GetResult();
        throw new Exception("Error on the server : " + erroResult);
    }
}

You need below namespaces at the top of your C# file:

您需要 C# 文件顶部的以下命名空间：

using System;
using System.Net;
using System.IO;
using System.Net.Http;

P.S. Sorry about so many using blocks(IDisposable pattern) in my code. Unfortunately, the syntax of using construct of C# doesn't support initializing multiple variables in single statement.

PS 很抱歉在我的代码中使用了这么多块（IDisposable 模式）。不幸的是，使用 C# 构造的语法不支持在单个语句中初始化多个变量。

回答by D.Oleg

Example with preloader Dotnet 3.0 Core

带有预加载器 Dotnet 3.0 Core 的示例

ProgressMessageHandler processMessageHander = new ProgressMessageHandler();

processMessageHander.HttpSendProgress += (s, e) =>
{
    if (e.ProgressPercentage > 0)
    {
        ProgressPercentage = e.ProgressPercentage;
        TotalBytes = e.TotalBytes;
        progressAction?.Invoke(progressFile);
    }
};

using (var client = HttpClientFactory.Create(processMessageHander))
{
    var uri = new Uri(transfer.BackEndUrl);
    client.DefaultRequestHeaders.Authorization =
    new AuthenticationHeaderValue("Bearer", AccessToken);

    using (MultipartFormDataContent multiForm = new MultipartFormDataContent())
    {
        multiForm.Add(new StringContent(FileId), "FileId");
        multiForm.Add(new StringContent(FileName), "FileName");
        string hash = "";

        using (MD5 md5Hash = MD5.Create())
        {
            var sb = new StringBuilder();
            foreach (var data in md5Hash.ComputeHash(File.ReadAllBytes(FullName)))
            {
                sb.Append(data.ToString("x2"));
            }
            hash = result.ToString();
        }
        multiForm.Add(new StringContent(hash), "Hash");

        using (FileStream fs = File.OpenRead(FullName))
        {
            multiForm.Add(new StreamContent(fs), "file", Path.GetFileName(FullName));
            var response = await client.PostAsync(uri, multiForm);
            progressFile.Message = response.ToString();

            if (response.IsSuccessStatusCode) {
                progressAction?.Invoke(progressFile);
            } else {
                progressErrorAction?.Invoke(progressFile);
            }
            response.EnsureSuccessStatusCode();
        }
    }
}