将HttpContent转换为byte[]

Question

我目前正在开发一个c#web API。对于一个特定的调用，我需要使用ajax调用向API发送2个图像，以便API可以将它们保存为数据库中的varbinary（max）。

1. 如何从HttpContent对象中提取Image或byte[]
2. 我该怎么做两次？每个图像一次

-

var authToken = $("#AuthToken").val();
var formData = new FormData($('form')[0]);
debugger;
$.ajax({
    url: "/api/obj/Create/", 
    headers: { "Authorization-Token": authToken },
    type: 'POST',
    xhr: function () { 
        var myXhr = $.ajaxSettings.xhr();
        return myXhr;
    },
    data: formData,
    cache: false,
    contentType: false,
    processData: false
});

-

public async Task<int> Create(HttpContent content)
{
    if (!content.IsMimeMultipartContent())
    {
        throw new UnsupportedMediaTypeException("MIME Multipart Content is not supported");
    }
    return 3;
}

Answer 1

HttpContent有一个Async方法，它返回ByteArray，即（ByteArray的任务）

 Byte[] byteArray = await Content.ReadAsByteArrayAsync();

您可以同步运行方法

Byte[] byteArray = Content.ReadAsByteArrayAsync().Result;

Answer 2

if (!content.IsMimeMultipartContent())
{
    throw new UnsupportedMediaTypeException("MIME Multipart Content is not supported");
}
var uploadPath = **whatever**;
if (!Directory.Exists(uploadPath))
{
    Directory.CreateDirectory(uploadPath);
}
var provider = new MultipartFormDataStreamProvider(uploadPath);
await content.ReadAsMultipartAsync(provider);
return File.ReadAllBytes(provider.FileData[0].LocalFileName);

Answer 3

您可以使用HttpContent.ReadAsByteArrayAsync:

byte[] bytes = await response.Content.ReadAsByteArrayAsync();

或者，您可以使用HttpContent.ReadAsStreamAsync读取内容，并从中提取到byte[]：

var stream = await response.Content.ReadAsStreamAsync();
using (var memoryStream = new MemoryStream())
{
      await stream.CopyToAsync(memoryStream);
      return memoryStream.ToArray();
}

Answer 4

请查看ByteArrayContent class公开的CopyToAsync（Stream，TransportContext）方法。[msdn链接]