Application.Activated Event
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Occurs when an application becomes the foreground application.
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).
