Application.Activated Event

public:
 event EventHandler ^ Activated;

public event EventHandler Activated;

member this.Activated : EventHandler 

Public Custom Event Activated As EventHandler 

Public Event Activated As EventHandler 

Event Type

Examples

The following example shows how to detect when a standalone application activates and deactivates.

<Application 
 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
 x:Class="SDKSample.App"
 StartupUri="MainWindow.xaml"
 Activated="App_Activated" 
 Deactivated="App_Deactivated" />

using System;
using System.Windows;

namespace SDKSample
{
 public partial class App : Application
 {
 bool isApplicationActive;

 void App_Activated(object sender, EventArgs e)
 {
 // Application activated
 this.isApplicationActive = true;
 }

 void App_Deactivated(object sender, EventArgs e)
 {
 // Application deactivated
 this.isApplicationActive = false;
 }
 }
}

Imports System.Windows

Namespace SDKSample
 Partial Public Class App
 Inherits Application
 Private isApplicationActive As Boolean

 Private Sub App_Activated(ByVal sender As Object, ByVal e As EventArgs)
 ' Application activated
 Me.isApplicationActive = True
 End Sub

 Private Sub App_Deactivated(ByVal sender As Object, ByVal e As EventArgs)
 ' Application deactivated
 Me.isApplicationActive = False
 End Sub
 End Class
End Namespace

Remarks

A Windows Presentation Foundation application that has one or more open windows is activated (becomes the foreground application) when one of the windows is activated for the first time since the application was launched, or when one of the windows is activated while the application is inactive: Specifically, activation occurs when:

• An application opens its first window.

• A user switches to the application by using ALT+TAB or by using Task Manager.

• A user clicks the taskbar button for one of the windows in an application.

Applications that need to detect when they activate can handle the Activated event.

After an application is first activated, it may be deactivated and reactivated many times during its lifetime. If an application's behavior or state depends on its activation state, it can handle both Activated and Deactivated events to determine which activation state it's in.

Once an application becomes active, Activated will not be raised again until the application is deactivated, irrespective of how many windows within an application are activated while the application is active.

Activated is not raised for XAML browser applications (XBAPs).

See also

• OnActivated(EventArgs)
• Deactivated