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UserPreferenceChangingEventHandler Delegate

 

Represents the method that will handle the UserPreferenceChanging event.

Namespace:   Microsoft.Win32
Assembly:  System (in System.dll)

[HostProtectionAttribute(SecurityAction::LinkDemand, MayLeakOnAbort = true)]
public delegate void UserPreferenceChangingEventHandler(
	Object^ sender,
	UserPreferenceChangingEventArgs^ e
)

Parameters

sender
Type: System::Object^

The source of the event. When this event is raised by the SystemEvents class, this object is always null.

e
Type: Microsoft.Win32::UserPreferenceChangingEventArgs^

A UserPreferenceChangedEventArgs that contains the event data.

When you create a UserPreferenceChangingEventHandler delegate, you identify the method that will handle the event. To associate the event with your event-handling method, add an instance of the delegate to the event. The event-handling method is called whenever the event occurs, unless you remove the delegate. For more information about event-handler delegates, see NIB: Events and Delegates.

The following code example demonstrates how to use the UserPreferenceChangingEventHandler type to monitor the UserPreferenceChanging event. This code example is part of a larger example provided for the SystemEvents class.

#using <System.dll>

using namespace System;
using namespace Microsoft::Win32;

// This method is called when a user preference changes.
void SystemEvents_UserPreferenceChanging(Object^ sender,
     UserPreferenceChangingEventArgs^ e)
 {
     Console::WriteLine("The user preference is changing. Category={0}",
         e->Category);
 }

// This method is called when the palette changes.
void SystemEvents_PaletteChanged(Object^ sender, EventArgs^ e)
{
    Console::WriteLine("The palette changed.");
}

// This method is called when the display settings change.
void SystemEvents_DisplaySettingsChanged(Object^ sender,
    EventArgs^ e)
{
    Console::WriteLine("The display settings changed.");
}

int main()
{
    // Set the SystemEvents class to receive event notification
    // when a user preference changes, the palette changes, or
    // when display settings change.
    SystemEvents::UserPreferenceChanging += gcnew
        UserPreferenceChangingEventHandler(
        SystemEvents_UserPreferenceChanging);
    SystemEvents::PaletteChanged += gcnew
        EventHandler(SystemEvents_PaletteChanged);
    SystemEvents::DisplaySettingsChanged += gcnew
        EventHandler(SystemEvents_DisplaySettingsChanged);

    // For demonstration purposes, this application sits idle
    // waiting for events.
    Console::WriteLine("This application is waiting for system events.");
    Console::WriteLine("Press <Enter> to terminate this application.");
    Console::ReadLine();
}

// This code produces the following output.
//
//  This app is waiting for system events.
//  Press <Enter> to terminate this application.
//  Display Settings changed.
//  User preference is changing. Category=General

.NET Framework
Available since 1.1
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