OpenWriteCompletedEventArgs.Result Explanation?

Question

http://msdn.microsoft.com/en-us/library/system.net.openwritecompletedeventargs.result(VS.95).aspx

I'm writing a .NET app (Silverlight API) using the WebClient class. I'm simply wanting to get an XML-style result of a server script after uploading a file Async. I figured the Result stream inside of OpenWriteCompletedEventArgs would be what I would want to look at, but MSDN says Result is: "Gets a writable stream that is used to send data to a server.".. I honestly fail to see how you can write once completed. I wonder if I can actually read from this, and if I can't, how do I go about reading the server message after the upload?

static void UploadCompleted(object sender, OpenWriteCompletedEventArgs e)
{
   /* e.Result says its only a writable stream */
}

Answer 1

No, you don't read from this. The point of this event is to let you write the body of an HTTP request to the server. If you don't need to write any data in your request, you don't need this event. If you need to write data, you'd use this event and then read the result when later events fire.

If you need to read, you want to do it when a read event has completed - e.g. OpenReadCompleted.

Answer 2

The documentation could be ambiguous or you are not using the correct method. Here's an example:

client.UploadFileAsync(new Uri("http://example.com"), @"c:\work\foo.txt");
client.UploadFileCompleted += (sender, e) =>
{
    // e.Result is a byte[] containing the server response 
    // which in your case is XML
};

Answer 3

The OpenWriteCompleted event is invoked when the HTTP connection to the server has been established, not when the upload has finished. You write to the stream to upload your data and close the stream when you're done.

There doesn't seem a way to obtain the response from the server when using OpenWriteAsync.