System.Net.ProtocolViolationException:在调用[Begin] GetResponse之前,必须将ContentLength字节写入请求流

Question

我得到了

"System.Net.ProtocolViolationException:在调用Web请求的"BeginGetResponse"方法时,必须在调用[Begin] GetResponse"错误之前将ContentLength字节写入请求流.

这是我的代码:

try
{
    Stream dataStream = null;
    WebRequest Webrequest;
    Webrequest = WebRequest.Create(this.EndPointAddress);
    Webrequest.Credentials = new NetworkCredential(this.username, this.password);

    Webrequest.ContentType = "text/xml";
    Webrequest.Method = WebRequestMethods.Http.Post;                    

    byteArray = System.Text.Encoding.UTF8.GetBytes(xmlRequest.Children[0].InnerXML);

    Webrequest.ContentLength = byteArray.Length;

    dataStream = Webrequest.GetRequestStream();
    dataStream.Write(byteArray, 0, byteArray.Length);                

    RequestState rs = new RequestState();
    rs.Request = Webrequest;                    

    IAsyncResult r = (IAsyncResult)Webrequest.BeginGetResponse(new AsyncCallback(RespCallback), rs);
}
catch (Exception exc)
{                    
    TRACE.EXCEPTION(exc);
}
finally
{
    dataStream.Close();
}

更具体地说,在调用函数"getRequestStream()"之后,Stream正在为长度抛出此异常:

'stream.Length'抛出了'System.NotSupportedException'类型的异常

可能是什么原因造成的？

Answer 1

这最终通过使用:

using (dataStream = Webrequest.GetRequestStream())
{
   dataStream.Write(byteArray, 0, byteArray.Length);
}

代替:

dataStream = Webrequest.GetRequestStream();
dataStream.Write(byteArray, 0, byteArray.Length);