blocks|key|322698|text|它的工作原理大致如下(以image/jpg文件为例)：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|322699|async+public+Task<HttpResponseMessage>+UploadImage(string+url,+byte[]+ImageData)
{
++++var+requestContent+=+new+MultipartFormDataContent();+
++++//++++here+you+can+specify+boundary+if+you+need---%5E
++++var+imageContent+=+new+ByteArrayContent(ImageData);
++++imageContent.Headers.ContentType+=+
++++++++MediaTypeHeaderValue.Parse("image/jpeg");

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

++++return+await+client.PostAsync(url,+requestContent);
}|code-block|syntax|javascript|322700|(您可以随心所欲地使用requestContent.Add()，查看HttpContent+descendant以查看可传递的类型)|offset|length|style|CODE|322701|完成后，您将在HttpResponseMessage.Content中找到可以通过HttpContent.ReadAs*Async使用的响应内容。|322702|entityMap|0|LINK|mutability|MUTABLE|url|http://msdn.microsoft.com/en-us/library/system.net.http.httpcontent.aspx^0|0|0|B|K|Y|M|0|0|7|R|15|O|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Y|8|@$I|Z|J|10|K|L]]|9|@$I|11|J|12|1|13]]|A|$]]|$1|M|3|N|5|6|7|14|8|@$I|15|J|16|K|L]|$I|17|J|18|K|L]]|9|@]|A|$]]|$1|O|3|-4|5|6|7|19|8|@]|9|@]|A|$]]]|P|$Q|$5|R|S|T|A|$U|V]]]]

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

<pre><code>async public Task&lt;HttpResponseMessage&gt; 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);
}
</code></pre>

(You can <code>requestContent.Add()</code> whatever you want, take a look at the <a href="http://msdn.microsoft.com/en-us/library/system.net.http.httpcontent.aspx">HttpContent descendant</a> to see available types to pass in)

When completed, you'll find the response content inside <code>HttpResponseMessage.Content</code> that you can consume with <code>HttpContent.ReadAs*Async</code>.

blocks|key|322725|text|我的结果如下所示：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|322726|public+static+async+Task<string>+Upload(byte[]+image)
{
+++++using+(var+client+=+new+HttpClient())
+++++{
+++++++++using+(var+content+=
+++++++++++++new+MultipartFormDataContent("Upload----"+%2B+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;
++++++++++++++}
++++++++++}
+++++}
}|code-block|syntax|javascript|322727|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

my result looks like this:

<pre><code>public static async Task&lt;string&gt; 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;
 }
 }
 }
}
</code></pre>

blocks|key|105670|text|这是一个使用MultipartFormDataContent在HTTPClient中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：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|105671|这是我的例子。希望它能有所帮助：|105672|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=\""+%2B+Path.GetFileName(path)+%2B+"\"");
++++++++++++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();
++++++++}
++++}
}|code-block|syntax|javascript|105673|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

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:

Here's my example. Hope it helps:

<pre><code>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&lt;HttpResponseMessage&gt; message = client.PostAsync("http://api.brightcove.com/services/post", content);

 var input = message.Result.Content.ReadAsStringAsync();
 Console.WriteLine(input.Result);
 Console.Read();
 }
 }
}
</code></pre>

blocks|key|322810|text|这是一个适用于我的完整示例。请求中的boundary值由.NET自动添加。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|322811|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;|code-block|syntax|javascript|322812|entityMap^0|I|8|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

Here's a complete sample that worked for me. The <code>boundary</code> value in the request is added automatically by .NET.

<pre><code>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;
</code></pre>

blocks|key|322831|text|试试这个，它对我很管用。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|322832|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;
}|code-block|syntax|javascript|322833|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Try this its working for me.

<pre class="lang-cs prettyprint-override"><code>private static async Task&lt;object&gt; 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;
}
</code></pre>

blocks|key|105804|text|这是另一个关于如何使用HttpClient上传multipart/form-data的示例。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|105805|它将文件上传到REST+API，并包括文件本身(例如JPG)和其他API参数。文件通过FileStream直接从本地磁盘上传。|105806|有关完整的示例，请参阅here。|105807|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);
}|code-block|syntax|javascript|105808|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/a/53284161/4379151^0|B|A|N|J|0|17|A|0|B|4|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@$9|X|A|Y|B|C]|$9|Z|A|10|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|11|8|@$9|12|A|13|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|14|8|@]|D|@$9|15|A|16|1|17]]|E|$]]|$1|J|3|K|5|L|7|18|8|@]|D|@]|E|$M|N]]|$1|O|3|-4|5|6|7|19|8|@]|D|@]|E|$]]]|P|$Q|$5|R|S|T|E|$U|V]]]]

Here is another example on how to use <code>HttpClient</code> to upload a <code>multipart/form-data</code>.

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 <code>FileStream</code>.

See <a href="https://stackoverflow.com/a/53284161/4379151">here</a> for the full example including additional API specific logic.

<pre><code>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);
}
</code></pre>

blocks|key|322887|text|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;
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|322888|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre class="lang-cs prettyprint-override"><code>public async Task&lt;object&gt; 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;
}
</code></pre>

blocks|key|105821|text|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();
++++}
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|105822|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre class="lang-cs prettyprint-override"><code>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) =&gt;
{
 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();
 }
}
</code></pre>

blocks|key|105873|text|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+verb公开的API。上载带有DELETE+http动词的文件的情况并不常见，但这是允许的。我已假定Windows+NTLM身份验证用于授权调用。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|105874|可能会遇到的问题是，HttpClient.DeleteAsync方法的所有重载都不像我们在PostAsync方法中获得的那样具有HttpContent的参数|offset|length|style|CODE|105875|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+:+"+%2B+erroResult);
++++}
}|code-block|syntax|javascript|105876|您需要在C#文件的顶部使用以下名称空间：|105877|using+System;
using+System.Net;
using+System.IO;
using+System.Net.Http;|105878|另外，很抱歉在我的代码中使用了这么多块(IDisposable模式)。不幸的是，使用构造的语法不支持在单个语句中初始化多个变量。|105879|entityMap^0|0|A|M|19|9|1S|B|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|V|8|@$D|W|E|X|F|G]|$D|Y|E|Z|F|G]|$D|10|E|11|F|G]]|9|@]|A|$]]|$1|H|3|I|5|J|7|12|8|@]|9|@]|A|$K|L]]|$1|M|3|N|5|6|7|13|8|@]|9|@]|A|$]]|$1|O|3|P|5|J|7|14|8|@]|9|@]|A|$K|L]]|$1|Q|3|R|5|6|7|15|8|@]|9|@]|A|$]]|$1|S|3|-4|5|6|7|16|8|@]|9|@]|A|$]]]|T|$]]

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.
The problem that one might face is that all the overloads of <code>HttpClient.DeleteAsync</code> method have no parameters for <code>HttpContent</code> the way we get it in <code>PostAsync</code> method
<pre class="lang-cs prettyprint-override"><code>var requestUri = new Uri(&quot;http://UrlOfTheApi&quot;);
using (var streamToPost = new MemoryStream(&quot;C:\temp.txt&quot;))
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, &quot;myFile&quot;, &quot;temp.txt&quot;);
 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(&quot;Error on the server : &quot; + erroResult);
 }
}
</code></pre>
You need below namespaces at the top of your C# file:
<pre class="lang-cs prettyprint-override"><code>using System;
using System.Net;
using System.IO;
using System.Net.Http;
</code></pre>
P.S. Apologies for so many using blocks(IDisposable pattern) in my code. Unfortunately, the syntax of using construct doesn't support initializing multiple variables in single statement.

blocks|key|105884|text|使用预加载器Dotnet+3.0核心的示例|type|unstyled|depth|inlineStyleRanges|entityRanges|data|105885|ProgressMessageHandler+processMessageHander+=+new+ProgressMessageHandler();

processMessageHander.HttpSendProgress+%2B=+(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();
++++++++}
++++}
}|code-block|syntax|javascript|105886|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Example with preloader Dotnet 3.0 Core

<pre class="lang-cs prettyprint-override"><code>ProgressMessageHandler processMessageHander = new ProgressMessageHandler();

processMessageHander.HttpSendProgress += (s, e) =&gt;
{
 if (e.ProgressPercentage &gt; 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();
 }
 }
}
</code></pre>

Does anyone know how to use the <code>HttpClient</code> in .Net 4.5 with <code>multipart/form-data</code> upload? 

I couldn't find any examples on the internet.

C# HttpClient 4.5 multipart/form-data upload

身份验证

Windows

有人知道如何在.Net 4.5中通过multipart/form-data upload使用HttpClient吗？我在网上找不到任何例子。

问C# HttpClient 4.5分块/表单数据上载
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