使用HttpClient发布自定义类型

Question

我有一个自定义dto类：

public class myObject
{
    public string Id { get; set; }
    public string Name { get; set; }
}

和一个使用Web Api（4.5. net框架）的控制器

[HttpPost]
public IHttpActionResult StripArchiveMailboxPermissions(myObject param)
{
    DoSomething(param);
    return OK();
}

客户端只有4.0.net框架，因此我将无法使用PostAsJsonAsync（）方法。将对象从客户端传递到服务器的解决方案是什么？

我尝试了如下方法：

var response = Client.SendAsync(new HttpRequestMessage<myObject>(objectTest)).Result;

然而它给了我一个例外:

Could not load file or assembly 'Microsoft.Json, Version=2.0.0.0, 
Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. 
The system cannot find the file specified.

难道不能使用牛顿软件库吗？

Answer 1

创建一个从 HttpContent 继承的类，该类为您提供了网络流，您可以直接写入该类，而无需使用 memoryStream

大概是这样的:

using System;
using System.IO;
using System.Net;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;
using Newtonsoft.Json;

namespace Http.Helper.Extensions
{
    public class JsonHttpContentSerializer : HttpContent
    {

        private object Value { get; set; }

        public JsonHttpContentSerializer(Object value)
        {
            this.Value = value;
        }


        protected override async Task SerializeToStreamAsync(Stream stream, TransportContext context)
        {
            using (var streamWriter = new StreamWriter(stream, new UTF8Encoding(false), 1024, true))
            {
                using (var jsonTextWriter = new JsonTextWriter(streamWriter) { Formatting = Formatting.None })
                {
                    var jsonSerializer = new JsonSerializer();
                    jsonSerializer.Serialize(jsonTextWriter, Value);
                    jsonTextWriter.Flush();
                }
            }

        }

        protected override bool TryComputeLength(out long length)
        {
            length = -1;
            return false;
        }

    }
}

你会用喜欢它

var jsonSerializeContent = new JsonHttpContentSerializer(someContent);
httpRequestMessage.Content = jsonSerializeContent;

Answer 2

当然。只需为自己创建一个像这样的新HttpContent类...

  public class JsonContent : HttpContent
    {

        private readonly MemoryStream _Stream = new MemoryStream();

        public JsonContent(object value)
        {

            var jw = new JsonTextWriter(new StreamWriter(_Stream)) {Formatting = Formatting.Indented};
            var serializer = new JsonSerializer();
            serializer.Serialize(jw, value);
            jw.Flush();
            _Stream.Position = 0;

        }
        protected override Task SerializeToStreamAsync(Stream stream, TransportContext context)
        {
            _Stream.CopyTo(stream);
            var tcs = new TaskCompletionSource<object>();
            tcs.SetResult(null);
            return tcs.Task;
        }

        protected override bool TryComputeLength(out long length)
        {
            length = _Stream.Length;
            return true;
        }
    }

现在，您可以将对象作为Json发送，如下所示

  var content = new JsonContent(new YourObject());
  var httpClient = new HttpClient();
  var response = httpClient.PostAsync("http://example.org/somewhere", content);