C# ASP.NET WebApi：如何使用 WebApi HttpClient 执行带有文件上传的多部分发布
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/10339877/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
ASP.NET WebApi: how to perform a multipart post with file upload using WebApi HttpClient
提问by Michael Teper
I have a WebApi service handling an upload from a simple form, like this one:
我有一个 WebApi 服务处理来自一个简单表单的上传，如下所示：
<form action="/api/workitems" enctype="multipart/form-data" method="post">
<input type="hidden" name="type" value="ExtractText" />
<input type="file" name="FileForUpload" />
<input type="submit" value="Run test" />
</form>
However, I can't figure out how to simulate the same post using the HttpClient API. The FormUrlEncodedContentbit is simple enough, but how do I add the file contents with the name to the post?
但是，我不知道如何使用 HttpClient API 模拟相同的帖子。这FormUrlEncodedContent一点很简单，但是如何将带有名称的文件内容添加到帖子中？
采纳答案by Michael Teper
After much trial and error, here's code that actually works:
经过多次反复试验，以下是实际有效的代码：
using (var client = new HttpClient())
{
using (var content = new MultipartFormDataContent())
{
var values = new[]
{
new KeyValuePair<string, string>("Foo", "Bar"),
new KeyValuePair<string, string>("More", "Less"),
};
foreach (var keyValuePair in values)
{
content.Add(new StringContent(keyValuePair.Value), keyValuePair.Key);
}
var fileContent = new ByteArrayContent(System.IO.File.ReadAllBytes(fileName));
fileContent.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment")
{
FileName = "Foo.txt"
};
content.Add(fileContent);
var requestUri = "/api/action";
var result = client.PostAsync(requestUri, content).Result;
}
}
回答by Aliostad
You need to look for various subclasses of HttpContent.
您需要寻找HttpContent.
You create a multiform http content and add various parts to it. In your case you have a byte array content and form url encoded along the lines of:
您创建了一个多形式的 http 内容并向其中添加了各个部分。在您的情况下，您有一个字节数组内容和表单 url沿以下行编码：
HttpClient c = new HttpClient();
var fileContent = new ByteArrayContent(new byte[100]);
fileContent.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment")
{
FileName = "myFilename.txt"
};
var formData = new FormUrlEncodedContent(new[]
{
new KeyValuePair<string, string>("name", "ali"),
new KeyValuePair<string, string>("title", "ostad")
});
MultipartContent content = new MultipartContent();
content.Add(formData);
content.Add(fileContent);
c.PostAsync(myUrl, content);
回答by ThiagoPXP
Thank you @Michael Tepper for your answer.
谢谢@Michael Tepper 的回答。
I had to post attachments to MailGun (email provider) and I had to modify it slightly so it would accept my attachments.
我不得不将附件发布到 MailGun（电子邮件提供商），我不得不稍微修改它以便它接受我的附件。
var fileContent = new ByteArrayContent(System.IO.File.ReadAllBytes(fileName));
fileContent.Headers.ContentDisposition =
new ContentDispositionHeaderValue("form-data") //<- 'form-data' instead of 'attachment'
{
Name = "attachment", // <- included line...
FileName = "Foo.txt",
};
multipartFormDataContent.Add(fileContent);
Here for future reference. Thanks.
此处供日后参考。谢谢。
