Occurs when an application becomes the foreground application.
Assembly: PresentationFramework (in PresentationFramework.dll)
A Windows Presentation Foundation (WPF) 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 theevent.
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 Deactivated events to determine which activation state it's in.and
Once an application becomes active,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.
is not raised for XAML browser applications (XBAPs).
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" />
Available since 3.0