Command Enabling : Command « Windows Presentation Foundation « VB.Net Tutorial

1. VB.Net Tutorial
2. Windows Presentation Foundation
3. Command

<Window x:Class="WpfApplication1.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="CommandEnabling" Height="300" Width="300"
    >
  <Grid>
    <Menu VerticalAlignment="Top">
      <MenuItem Header="_Edit">
        <MenuItem Command="Redo" />
      </MenuItem>
    </Menu>
  </Grid>
</Window>



//File:Window.xaml.vb
Imports System
Imports System.Collections.Generic
Imports System.Text
Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Data
Imports System.Windows.Documents
Imports System.Windows.Input
Imports System.Windows.Media
Imports System.Windows.Media.Imaging
Imports System.Windows.Shapes


Namespace WpfApplication1
  Public Partial Class Window1
    Inherits System.Windows.Window
    Public Sub New()
      InitializeComponent()

      Dim redoCommandBinding As New CommandBinding(ApplicationCommands.Redo)
      AddHandler redoCommandBinding.CanExecute, AddressOf RedoCommandCanExecute
      CommandBindings.Add(redoCommandBinding)
    End Sub

    Private Sub RedoCommandCanExecute(sender As Object, e As CanExecuteRoutedEventArgs)
      e.CanExecute = DateTime.Now.Second Mod 2 > 1
    End Sub
  End Class
End Namespace

16.89.Command
	16.89.1.	Invoking Copy command with a Button
	16.89.2.	Button CommandTarget Binding
	16.89.3.	Creating CommandBinding and attaching an Executed and CanExecute handler
	16.89.4.	Command Handler Command Binding in Xaml
	16.89.5.	Property changed callback
	16.89.6.	Using CommandBinding and ExecutedRoutedEventHandler to bind Application event to an event handler method
	16.89.7.	Create CommandBindings in Xaml and bind to Button
	16.89.8.	Bind TextBox save command to CommandBinding
	16.89.9.	Press F1 to get help
	16.89.10.	Help command
	16.89.11.	Command Enabling