C# 中的 HttpClient 多部分表单发布
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HttpClient Multipart Form Post in C#
提问by Khalid Abuhakmeh
I'm trying to do a multipart form post using the HttpClient in C# and am finding the following code does not work.
我正在尝试使用 C# 中的 HttpClient 进行多部分表单发布，但发现以下代码不起作用。
Important:
重要的：
var jsonToSend = JsonConvert.SerializeObject(json, Formatting.None, new IsoDateTimeConverter());
var multipart = new MultipartFormDataContent();
var body = new StringContent(jsonToSend, Encoding.UTF8, "application/json");
multipart.Add(body);
multipart.Add(new ByteArrayContent(File.ReadAllBytes("test.txt")), "test", "test.txt");
var httpClient = new HttpClient();
var response = httpClient.PostAsync(new Uri("http://localhost:55530"), multipart).Result;
Full Program:
完整程序：
namespace CourierMvc.Worker
{
class Program
{
static void Main(string[] args)
{
while (true)
{
Console.WriteLine("Hit any key to make request.");
Console.ReadKey();
try
{
var request = new RestRequest(Method.POST)
{
Resource = "http://localhost:55530"
};
var json = new CourierMessage
{
Id = Guid.NewGuid().ToString(),
Key = "awesome",
From = "[email protected]",
To = new[] { "[email protected]", "[email protected]" },
Subject = "test",
Body = "body",
Processed = DateTimeOffset.UtcNow,
Received = DateTime.Now,
Created = DateTime.Now,
Sent = DateTime.Now,
Links = new[] { new Anchor { Link = "http://google.com" }, new Anchor { Link = "http://yahoo.com" } }
};
var jsonToSend = JsonConvert.SerializeObject(json, Formatting.None, new IsoDateTimeConverter());
var multipart = new MultipartFormDataContent();
var body = new StringContent(jsonToSend, Encoding.UTF8, "application/json");
multipart.Add(body);
multipart.Add(new ByteArrayContent(File.ReadAllBytes("test.txt")), "test", "test.txt");
var httpClient = new HttpClient();
var response = httpClient.PostAsync(new Uri("http://localhost:55530"), multipart).Result;
}
catch (Exception e)
{
Console.WriteLine(e);
}
}
}
}
}
I really have no idea why it doesn't work. I get the file to post to the endpoint, but the body (json) never gets there. Am I doing something wrong?
我真的不知道为什么它不起作用。我将文件发布到端点，但正文（json）从未到达那里。难道我做错了什么？
Server Side Code Request:
服务器端代码请求：
namespace CourierMvc.Controllers
{
public class HomeController : Controller
{
//
// GET: /Home/
public ActionResult Index()
{
return Content("Home#Index");
}
[ValidateInput(false)]
public ActionResult Create(CourierMessage input)
{
var files = Request.Files;
return Content("OK");
}
}
}
Route Config:
路由配置：
public static void RegisterRoutes(RouteCollection routes)
{
routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
routes.MapRoute(
name: "Default",
url: "{controller}/{action}/{id}",
defaults: new { controller = "Home", action = "Create", id = UrlParameter.Optional }
);
}
采纳答案by Jay
So the problem I'm seeing is that the MultipartFormDataContentrequest message will always set the content type of the request to "multipart/form-data". Endcoding json and placing that into the request only "looks" like to the model binder as a string.
所以我看到的问题是MultipartFormDataContent请求消息总是将请求的内容类型设置为“multipart/form-data”。结束编码 json 并将其放入请求中，对于模型绑定器来说，它只是“看起来”像一个字符串。
Your options are:
您的选择是：
- have your mvc action method receive a string and deserialize into your object
- post each property of your model as a form part
- create a custom model binder that will handle your request.
- Breakup the operation into two posts, first sends the json metadata, the other sends the file. The response from the server should send some id or key to correlate the two requests.
- 让您的 mvc 操作方法接收一个字符串并反序列化为您的对象
- 将模型的每个属性作为表单部件发布
- 创建一个自定义模型绑定器来处理您的请求。
- 将操作拆分成两个帖子，先发送json元数据，另一个发送文件。来自服务器的响应应该发送一些 id 或密钥来关联两个请求。
Reading through the RFC documentand the MSDN documentationyou may be able to do this, if you replace MultipartFormDataContentwith MultipartContent. But I have not tested this yet.
通读RFC 文档和 MSDN 文档，如果您将其替换MultipartFormDataContent为MultipartContent. 但我还没有测试过这个。
回答by Matija Grcic
public class CourierMessage
{
public string Id { get; set; }
public string Key { get; set; }
public string From { get; set; }
public string Subject { get; set; }
public string Body { get; set; }
public DateTimeOffset Processed { get; set; }
public DateTime Received { get; set; }
public DateTime Created { get; set; }
public DateTime Sent { get; set; }
public HttpPostedFileBase File { get; set; }
}
while (true)
{
Console.WriteLine("Hit any key to make request.");
Console.ReadKey();
using (var client = new HttpClient())
{
using (var multipartFormDataContent = new MultipartFormDataContent())
{
var values = new[]
{
new KeyValuePair<string, string>("Id", Guid.NewGuid().ToString()),
new KeyValuePair<string, string>("Key", "awesome"),
new KeyValuePair<string, string>("From", "[email protected]")
//other values
};
foreach (var keyValuePair in values)
{
multipartFormDataContent.Add(new StringContent(keyValuePair.Value),
String.Format("\"{0}\"", keyValuePair.Key));
}
multipartFormDataContent.Add(new ByteArrayContent(File.ReadAllBytes("test.txt")),
'"' + "File" + '"',
'"' + "test.txt" + '"');
var requestUri = "http://localhost:5949";
var result = client.PostAsync(requestUri, multipartFormDataContent).Result;
}
}
}
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");
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();
}
}
}
