Adding data to Silverlight HTTP POST Async

Question

I am trying to send some data using a simple HTTP POST in Silverlight 3.0, but for some reason I cannot find a good example of how to do this.

While this works, but how can I send some data on request?

Public Sub SubmitMessage()
    request = WebRequestCreator.ClientHttp.Create(New System.Uri("http://localhost:27856/Home.aspx/PostUpdate/"))
    request.Method = "POST"

    Dim result As IAsyncResult = request.BeginGetResponse(New AsyncCallback(AddressOf UpdateDone), Nothing)
End Sub

Public Sub UpdateDone(ByVal ar As IAsyncResult)
    Dim response As HttpWebResponse = request.EndGetResponse(ar)

    Using reader As StreamReader = New StreamReader(response.GetResponseStream())
        Dim valid As String = reader.ReadToEnd()
    End Using
End Sub

Answer 1

You need a method BeginGetRequestStreambefore getting an answer (note that VB.NET is not my main language).

Public Sub SubmitMessage()
    request = WebRequestCreator.ClientHttp.Create(New System.Uri("http://localhost:27856/Home.aspx/PostUpdate/"))
    request.Method = "POST"

    request.BeginGetRequestStream(New AsyncCallback(AddressOf SendData), Nothing)
End Sub

Public Sub SendData(ByVal ar As IAsyncResult)
    Dim stream as Stream = state.Request.EndGetRequestStream(ar)
    '' # Pump your data as bytes into the stream.
    stream.Close()
    request.BeingGetResponse(New AsyncCallback(AddressOf UpdateDone), Nothing)
End Sub

Public Sub UpdateDone(ByVal ar As IAsyncResult)
    Dim response As HttpWebResponse = request.EndGetResponse(ar)

    Using reader As StreamReader = New StreamReader(response.GetResponseStream())
        Dim valid As String = reader.ReadToEnd()
    End Using
End Sub

It would seem from your answer that you are submitting HTML form data. Here is the right way to create an object body (C # sorry): -

    public static string GetUrlEncodedData(Dictionary<string, string> data)
    {
        var sb = new StringBuilder();
        foreach (var kvp in data)
        {
            if (sb.Length > 0) sb.Append("&");
            sb.Append(kvp.Key);
            sb.Append("=");
            sb.Append(Uri.EscapeDataString(kvp.Value));
        }
        return sb.ToString();
    }

, , Uri.EscapeDataString, Content-Type. , UTF-8.

, , ASCII, ASCII.

Answer 2

, , . @AnthonyWJones , !

Public Sub SubmitMessage()
    Dim request As HttpWebRequest = WebRequestCreator.ClientHttp.Create(New System.Uri("http://localhost:27856/Home.aspx/PostUpdate/"))
    request.Method = "POST"
    request.ContentType = "application/x-www-form-urlencoded"

    request.BeginGetRequestStream(New AsyncCallback(AddressOf SendStatusUpdate), request)
End Sub

Public Sub SendStatusUpdate(ByVal ar As IAsyncResult)
    Dim request As HttpWebRequest = DirectCast(ar.AsyncState, HttpWebRequest)

    Dim stream As Stream = request.EndGetRequestStream(ar)

    Dim data As New System.Text.UTF8Encoding
    Dim byteArray As Byte() = data.GetBytes("status=test")

    stream.Write(byteArray, 0, byteArray.Length)
    stream.Close()
    stream.Dispose()

    request.BeginGetResponse(New AsyncCallback(AddressOf StatusUpdateCompleted), request)
End Sub

Public Sub StatusUpdateCompleted(ByVal ar As IAsyncResult)
    Dim request As HttpWebRequest = DirectCast(ar.AsyncState, HttpWebRequest)

    Dim response As HttpWebResponse = request.EndGetResponse(ar)

    Using reader As StreamReader = New StreamReader(response.GetResponseStream())
        Dim valid As String = reader.ReadToEnd()
    End Using
End Sub