Visual Basic Improvements in Visual Studio 11: Listing 1.

Loading the four Web pages with synchronous Get method.

Const msdnURL = ""
  Const bingURL = ""

  Private Sub btnLoadPagesSync_Click(sender As Object, e As EventArgs) Handles btnLoadPagesSync.Click
    'No Web pages will appear until they are all loaded
    Call DoLoadPagesSync()
  End Sub

  Private Sub DoLoadPagesSync()
    'Load each page synchronously over http for demo
    btnLoadPagesSync.BackColor = Color.Red
    Dim StartTime = Now
    UpdateWebControlSync(msdnURL, wb1)
    UpdateWebControlSync(bingURL, wb2)
    UpdateWebControlSync(msdnURL, wb3)
    UpdateWebControlSync(bingURL, wb4)
    btnLoadPagesSync.BackColor = System.Windows.Forms.Button.DefaultBackColor
    lblElapsedSynch.Text = "Button response Time: " & DateTime.Now.Subtract(StartTime).ToString
  End Sub

  Private Sub UpdateWebControlSync(webPageURL As String, wc As WebBrowser)
    'Simple method to display Web pages on a windows form
      wc.DocumentText = ""

      'Using synchonous Get method rather than asynchronous GetAsync method
      'Synchronous call to retrieve the HTML, method is not suspended during load
      Dim response = New System.Net.Http.HttpClient().Get(New System.Uri(webPageURL))

      'Sync method as completed and execution continues
      Dim pageHTML = response.Content.ReadAsString
    Catch ex As Exception
      Dim msg = "Exception: {0}" & vbCrLf & vbCrLf & "{1}"
      MessageBox.Show(String.Format(msg, ex.Message, ex.InnerException.Message))
    End Try
  End Sub

About the Author

Joe Kunk is a Microsoft MVP in Visual Basic, three-time president of the Greater Lansing User Group for .NET, and developer for Dart Container Corporation of Mason, Michigan. He's been developing software for over 30 years and has worked in the education, government, financial and manufacturing industries. Kunk's co-authored the book "Professional DevExpress ASP.NET Controls" (Wrox Programmer to Programmer, 2009). He can be reached via email at [email protected].

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