TextBox focus listener : TextBox « Windows Presentation Foundation « VB.Net

1. VB.Net
2. Windows Presentation Foundation
3. TextBox

TextBox focus listener

   
<Window x:Class="WpfApplication1.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:custom="clr-namespace:WpfApplication1"
    Title="Keyboard Sample" Height="250" Width="300">
    <StackPanel>
        <Label Name="lblNumberOfTargetHits" HorizontalAlignment="Center"/>
        <TextBox Name="txtTargetKey" GotKeyboardFocus="TextBoxGotKeyboardFocus" LostKeyboardFocus="TextBoxLostKeyboardFocus">A</TextBox>
        <TextBox TextWrapping="Wrap" GotKeyboardFocus="TextBoxGotKeyboardFocus" LostKeyboardFocus="TextBoxLostKeyboardFocus" KeyDown="SourceTextKeyDown"/>
    </StackPanel>

</Window>


//File:Window.xaml.vb

Imports System
Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Data
Imports System.Windows.Documents
Imports System.Windows.Media
Imports System.Windows.Media.Imaging
Imports System.Windows.Shapes
Imports System.Windows.Annotations
Imports System.Windows.Input
Namespace WpfApplication1
  Public Partial Class Window1
    Inherits Window

    Public Sub New()
      InitializeComponent()
    End Sub

    Private Sub TextBoxGotKeyboardFocus(sender As Object, e As KeyboardFocusChangedEventArgs)
      Dim source As TextBox = TryCast(e.Source, TextBox)
      If source IsNot Nothing Then
        source.Background = Brushes.LightBlue
        source.Clear()
      End If
    End Sub
    Private Sub TextBoxLostKeyboardFocus(sender As Object, e As KeyboardFocusChangedEventArgs)
      Dim source As TextBox = TryCast(e.Source, TextBox)

      If source IsNot Nothing Then
        source.Background = Brushes.White
      End If
    End Sub
    Private Sub SourceTextKeyDown(sender As Object, e As KeyEventArgs)
      Dim converter As New KeyConverter()
      Dim target As Key = Key.None

      If txtTargetKey.Text.Length = 1 Then
        target = CType(converter.ConvertFromString(txtTargetKey.Text), Key)
      End If
    End Sub
  End Class
End Namespace

   
    
    
  

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