从HttpListenerRequest异步获取post数据可能吗？

Question

msdn给我们这个例子来检索post数据。

 public static void ShowRequestData (HttpListenerRequest request)
 {
     if (!request.HasEntityBody)
     {
         Console.WriteLine("No client data was sent with the request.");
         return;
     }
     System.IO.Stream body = request.InputStream;
     System.Text.Encoding encoding = request.ContentEncoding;
     System.IO.StreamReader reader = new System.IO.StreamReader(body, encoding);
     if (request.ContentType != null)
     {
         Console.WriteLine("Client data content type {0}", request.ContentType);
     }
     Console.WriteLine("Client data content length {0}", request.ContentLength64);

     Console.WriteLine("Start of client data:");
     // Convert the data to a string and display it on the console.
     string s = reader.ReadToEnd();
     Console.WriteLine(s);
     Console.WriteLine("End of client data:");
     body.Close();
     reader.Close();
     // If you are finished with the request, it should be closed also.
 }

source

我检查了Streamreader类，没有开始...结束..。方法。这是否意味着无法异步检索Post数据？或者在HttpListener的回调到来之前，它已经被检索到了？

我不想在一个慢速post数据块进来的时候得到线程停顿。

执行此操作的正确异步方式是什么？(或者ReadToEnd实际上是正确的？)

谢谢

R

Answer 1

您可以在传入的流上调用Stream.BeginRead，而不是使用StreamReader。

更新:下面是一个在流上使用BeginRead的示例：

class State
{
    public Stream Stream { get; set; }
    public byte[] Buffer { get; set; }
}

class Program
{
    private const int ChunkSize = 1024;
    static void Main(string[] args)
    {
        var stream = new FileStream("test.txt", FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
        var state = new State { Stream = stream, Buffer = new byte[ChunkSize] };
        var ar = stream.BeginRead(state.Buffer, 0, state.Buffer.Length, Callback, state);
        while (!ar.IsCompleted)
        {
            Thread.Sleep(10);
        }
    }

    static void Callback(IAsyncResult ar)
    {
        var state = (State)ar.AsyncState;
        var bytesRead = state.Stream.EndRead(ar);
        if (bytesRead > 0)
        {
            byte[] buffer = new byte[bytesRead];
            Buffer.BlockCopy(state.Buffer, 0, buffer, 0, bytesRead);
            // Do something with the received buffer.
            Console.Write(Encoding.UTF8.GetString(buffer));

            state.Stream.BeginRead(state.Buffer, 0, state.Buffer.Length, Callback, state);
        }
        else
        {
            // reached the end of the stream
            state.Stream.Dispose();
        }
    }
}