Beyond web logs

As you probably already know, Silverlight is a browser plugin for providing rich web content. It includes a subset of the capabilities of WPF, and it aims to rival Adobe Flash. However, submitting form data using POST in silverlight is not as trivial as you might imagine. You would need to create HttpWebRequest menthod to POST your silverlight based form data and that's not all. You will also need to go through many pitfalls like SynchronizationContext issues.

Here is the sample code to submit or POST form data in ASP.NET using Silverlight. I hope it would help you a lot in intergating your silverlight application in ASP.NET.

Private Sub btnSubmit_Click(ByVal sender As System.Object, ByVal e As System.Windows.RoutedEventArgs)
        syncContext = SynchronizationContext.Current
        For Each uie As UIElement In MasterPage.Children
            GetChilds(uie)
        Next
        Dim url As New Uri(HtmlPage.Document.DocumentUri, "processfile.aspx")
        Dim request As HttpWebRequest = DirectCast(WebRequest.Create(url), HttpWebRequest)
        request.Method = "POST"
        request.ContentType = "application/x-www-form-urlencoded"
        request.BeginGetRequestStream(New AsyncCallback(AddressOf RequestProceed), request)
End Sub

Private Sub RequestProceed(ByVal asyncResult As IAsyncResult)
        Dim request As HttpWebRequest = DirectCast(asyncResult.AsyncState, HttpWebRequest)
        Dim postData As New StreamWriter(request.EndGetRequestStream(asyncResult))
        postData.Write(formData)
        postData.Close()
        request.BeginGetResponse(New AsyncCallback(AddressOf RProceed), request)
End Sub

Private Sub RProceed(ByVal asyncResult As IAsyncResult)
        Dim request As HttpWebRequest = DirectCast(asyncResult.AsyncState, HttpWebRequest)
        Dim response As HttpWebResponse = request.EndGetResponse(asyncResult)
        syncContext.Post(AddressOf ExtractResponse, response)
End Sub

Private Sub ExtractResponse(ByVal state As Object)
        Dim response As HttpWebResponse = TryCast(state, HttpWebResponse)
        Dim url As New Uri(HtmlPage.Document.DocumentUri, "YourPage.aspx")
        HtmlPage.Window.Eval("window.location.href='" & url.ToString & "';")
End Sub

Private Sub GetChilds(ByVal uie As UIElement)
       Dim obj As String
         obj = uie.ToString
        names = names & obj

        If obj = "System.Windows.Controls.StackPanel" Then
            Dim sp As StackPanel
            sp = DirectCast(uie, System.Windows.Controls.StackPanel)
            For Each spChild As UIElement In sp.Children
                GetChilds(spChild)
            Next
        End If

        If obj = "System.Windows.Controls.Grid" Then
            Dim gv As Grid
            gv = DirectCast(uie, System.Windows.Controls.Grid)
            For Each gvChild As UIElement In gv.Children
                GetChilds(gvChild)
            Next
        End If
        If obj = "System.Windows.Controls.TextBox" Then
            Dim tb As TextBox
            tb = DirectCast(uie, System.Windows.Controls.TextBox)
            formData = formData & tb.Name & "$#*"
            formData = formData & tb.Text & "$#*;"
        End If
        If obj.Contains("System.Windows.Controls.RadioButton") Then
            Dim rb As RadioButton
            rb = DirectCast(uie, System.Windows.Controls.RadioButton)
            formData = formData & rb.Name & "$#*"
            formData = formData & rb.IsChecked & "$#*;"
        End If
        If obj.Contains("System.Windows.Controls.CheckBox") Then
            Dim cb As CheckBox
            cb = DirectCast(uie, System.Windows.Controls.CheckBox)
            formData = formData & cb.Name & "$#*"
            formData = formData & cb.IsChecked & "$#*;"
       End If
    End Sub