Delegate event Definition

Close the Child Window and tell the parent form

[Csharp]
Parent form
Previous paragraph:
<Window x: Class = "RefreshFatherWindow. WindowClose"
Xmlns = "http://schemas.microsoft.com/winfx/2006/xaml/presentation"
Xmlns: x = "http://schemas.microsoft.com/winfx/2006/xaml"
Title = "WindowClose" Height = "300" Width = "300">
<StackPanel>
<TextBox Name = "tb"/>
<Button Content = "submit" Click = "Button_Click"/>
</StackPanel>
</Window>
 
Viewcode:
Using System;
Using System. Collections. Generic;
Using System. Linq;
Using System. Text;
Using System. Windows;
Using System. Windows. Controls;
Using System. Windows. Data;
Using System. Windows. Documents;
Using System. Windows. Input;
Using System. Windows. Media;
Using System. Windows. Media. Imaging;
Using System. Windows. Shapes;
 
Namespace RefreshFatherWindow
{
/// <Summary>
/// Interaction logic for WindowClose. xaml
/// </Summary>
Public partial class WindowClose: Window
{
Public WindowClose ()
{
InitializeComponent ();
}
 
Private void Button_Click (object sender, RoutedEventArgs e)
{
SonWindow son = new SonWindow ();
 
Son. Closed + = new EventHandler (son_Closed );
Son. Show ();
}
 
Public void son_Closed (object obj, EventArgs e)
{
Tb. Text = "The son window is closed! ";
}
}
}
 
Subform:
Directly draw a form named SonWindow. xaml,
Click the close button X to pass the value to the parent form.

 

Sub-form click to pass the value to the parent form

[Csharp]
Parent form
Design:
<Window x: Class = "RefreshFatherWindow. MainWindow"
Xmlns = "http://schemas.microsoft.com/winfx/2006/xaml/presentation"
Xmlns: x = "http://schemas.microsoft.com/winfx/2006/xaml"
Title = "MainWindow" Height = "350" Width = "525">
<StackPanel>
<TextBox Name = "tb"/>
<Button Content = "submit" Click = "Button_Click"/>
</StackPanel>
</Window>
 
ViewCode:
Using System;
Using System. Collections. Generic;
Using System. Linq;
Using System. Text;
Using System. Windows;
Using System. Windows. Controls;
Using System. Windows. Data;
Using System. Windows. Documents;
Using System. Windows. Input;
Using System. Windows. Media;
Using System. Windows. Media. Imaging;
Using System. Windows. Navigation;
Using System. Windows. Shapes;
 
Namespace RefreshFatherWindow
{
/// <Summary>
/// Interaction logic for MainWindow. xaml
/// </Summary>
Public partial class MainWindow: Window
{
Public MainWindow ()
{
InitializeComponent ();
}
 
Private void Button_Click (object sender, RoutedEventArgs e)
{
SonWindow son = new SonWindow ();
Son. ChangeTextEvent + = new SonWindow. ChangeTextHandler (ChangeTextEvent );
Son. Show ();
}
 
Void ChangeTextEvent (string text)
{
Tb. Text = text;
}
 
}
}
 
Subform:
Design
<Window x: Class = "RefreshFatherWindow. SonWindow"
Xmlns = "http://schemas.microsoft.com/winfx/2006/xaml/presentation"
Xmlns: x = "http://schemas.microsoft.com/winfx/2006/xaml"
Title = "SonWindow" Height = "300" Width = "300">
<Grid>
<Button Content = "Click window effects" Click = "Button_Click"/>
</Grid>
</Window>
 
Viewcode:
Using System;
Using System. Collections. Generic;
Using System. Linq;
Using System. Text;
Using System. Windows;
Using System. Windows. Controls;
Using System. Windows. Data;
Using System. Windows. Documents;
Using System. Windows. Input;
Using System. Windows. Media;
Using System. Windows. Media. Imaging;
Using System. Windows. Shapes;
 
Namespace RefreshFatherWindow
{
/// <Summary>
/// Interaction logic for SonWindow. xaml
/// </Summary>
Public partial class SonWindow: Window
{
// Define the delegate
Public delegate void ChangeTextHandler (string text );
 
// Define the event
Public event ChangeTextHandler ChangeTextEvent;
 
 
Public SonWindow ()
{
InitializeComponent ();
}
 
Private void Button_Click (object sender, RoutedEventArgs e)
{
ChangeTextEvent ("I am the effect! ");
}
}
}
 

From pengshumin89