Binding Command to ApplicationCommands.New : ApplicationCommands « Windows Presentation Foundation « VB.Net Tutorial

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

<Window x:Class="WpfApplication1.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="CommandHandling" Height="300" Width="300"
    >
    <DockPanel>
      <Menu DockPanel.Dock="Top">
        <MenuItem Header="_File">
          <MenuItem Command="New" />
        </MenuItem>
      </Menu>
      <TextBox x:Name="inputBox" TextChanged="OnTextboxTextChanged" />
    </DockPanel>
</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 Window
    Private unsavedChanges As Boolean = False

    Public Sub New()
      InitializeComponent()

      Dim cmdBindingNew As New CommandBinding(ApplicationCommands.[New])
      AddHandler cmdBindingNew.Executed, AddressOf NewCommandHandler
      CommandBindings.Add(cmdBindingNew)
    End Sub

    Private Sub NewCommandHandler(sender As Object, e As ExecutedRoutedEventArgs)
      If unsavedChanges Then
        Dim result As MessageBoxResult = MessageBox.Show(Me, "Save changes to existing document?", "New", MessageBoxButton.YesNoCancel)

        If result = MessageBoxResult.Cancel Then
          Return
        End If
        If result = MessageBoxResult.Yes Then
          SaveChanges()
        End If
      End If
      inputBox.Clear()
    End Sub
    Private Sub OnTextboxTextChanged(sender As Object, e As RoutedEventArgs)
      unsavedChanges = True
      Console.WriteLine("changed")
    End Sub

    Private Sub SaveChanges()
      unsavedChanges = False
      Console.WriteLine("saved")
    End Sub

  End Class
End Namespace

16.93.ApplicationCommands
	16.93.1.	Without focus scope
	16.93.2.	Bind ApplicationCommand to a handler
	16.93.3.	Assign ApplicationCommands.Open to Button
	16.93.4.	Menu with Application command: cut, copy, paste
	16.93.5.	Binding command to ApplicationCommands.Redo
	16.93.6.	Binding Command to ApplicationCommands.New
	16.93.7.	Bind CanExecute to ApplicationCommands.Save
	16.93.8.	Binding ApplicationCommands.New Command to your own handler
	16.93.9.	Change ApplicationCommands.New.Text
	16.93.10.	Call ApplicationCommands.New.Execute to execute the command directly
	16.93.11.	Use CommandBinding to bind ApplicationCommands.New in code
	16.93.12.	Use CommandBinding to Bind to ApplicationCommands
	16.93.13.	Add ApplicationCommands.Cut to TextBox with TextBox.CommandBindings