/// <summary>
/// Inicia o processo assincrono de recuperação da stream de requisição.
/// </summary>
/// <param name="request"></param>
/// <param name="callback"></param>
/// <param name="state"></param>
/// <returns></returns>
public static IAsyncResult BeginGetRequestStream(System.Net.HttpWebRequest request, AsyncCallback callback, object state)
{
try
{
if (request.IsAborted())
{
throw new System.Net.WebException("The request was canceled.", System.Net.WebExceptionStatus.RequestCanceled);
}
bool flag = (((request.Method != "GET") && (request.Method != "CONNECT")) && (request.Method != "HEAD")) && (request.Method != "TRACE");
if (request.Method == null || !flag)
{
throw new System.Net.ProtocolViolationException("Cannot send data when method is: " + request.Method);
}
if ((request.ContentLength == -1L && !request.SendChunked) && (request.KeepAlive))
{
throw new System.Net.ProtocolViolationException("Content-Length not set");
}
string transferEncoding = request.TransferEncoding;
if ((!request.SendChunked && (transferEncoding != null)) && (transferEncoding.Trim() != string.Empty))
{
throw new System.Net.ProtocolViolationException("SendChunked should be true.");
}
object locker = request.GetLock();
lock (locker)
{
if (request.IsResponseCalled())
{
throw new InvalidOperationException("The operation cannot be performed once the request has been submitted.");
}
if (request.GetAsyncWrite() != null)
{
throw new InvalidOperationException("Cannot re-call start of asynchronous method while a previous call is still in progress.");
}
request.SetAsyncWrite(CreateWebAsyncResult(request, callback, state));
request.SetInitialMethod(request.Method);
var writeStream = request.GetWriteStream();
IAsyncResult asyncWrite = null;
if (request.HaveRequest() && (writeStream != null))
{
asyncWrite = request.GetAsyncWrite();
asyncWrite.SetCompleted(true, writeStream);
asyncWrite.DoCallback();
return(request.GetAsyncWrite());
}
request.SetGotRequestStream(true);
asyncWrite = request.GetAsyncWrite();
if (!request.IsRequestSent())
{
request.SetRequestSent(true);
request.SetRedirects(0);
var servicePoint = request.GetServicePoint();
request.SetServicePoint(servicePoint);
request.SetAbortHandler(servicePoint.SendRequest(request, request.GetConnectionGroup()));
}
return(asyncWrite);
}
}
catch (Exception ex)
{
throw new Exception(ex.ToString(), ex);
}
}