WPF VB.Net Tutorial

  x:Class="WpfApplication1.Window1"
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  Title="Window1" Height="600" Width="800">
  
    
      
      
    
    
  


//File:Window.xaml.vb
Imports System.Windows
Imports System.Windows.Documents
Imports System.Windows.Input
Namespace WpfApplication1
  Public Partial Class Window1
    Inherits Window
    Public Sub New()
      InitializeComponent()
    End Sub
    Private Sub btnInsert_Click(sender As Object, e As RoutedEventArgs)
      If String.IsNullOrEmpty(tbxInsertionText.Text) Then
        Return
      End If
      rtbTextContent.BeginChange()
      If rtbTextContent.Selection.Text <> String.Empty Then
        rtbTextContent.Selection.Text = String.Empty
      End If
      Dim tp As TextPointer = rtbTextContent.CaretPosition.GetPositionAtOffset(0, LogicalDirection.Forward)
      rtbTextContent.CaretPosition.InsertTextInRun(tbxInsertionText.Text)
      rtbTextContent.CaretPosition = tp
      rtbTextContent.EndChange()
      Keyboard.Focus(rtbTextContent)
    End Sub
  End Class
End Namespace