UserPreferenceChangingEventHandler Delegate
Assembly: System (in system.dll)
'Declaration Public Delegate Sub UserPreferenceChangingEventHandler ( _ sender As Object, _ e As UserPreferenceChangingEventArgs _ ) 'Usage Dim instance As New UserPreferenceChangingEventHandler(AddressOf HandlerMethod)
/** @delegate */ public delegate void UserPreferenceChangingEventHandler ( Object sender, UserPreferenceChangingEventArgs e )
JScript supports the use of delegates, but not the declaration of new ones.
Parameters
- sender
The source of the event. When this event is raised by the SystemEvents class, this object is always a null reference (Nothing in Visual Basic).
- e
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 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.
Imports System Imports Microsoft.Win32 Imports System.Windows.Forms Friend Class Form1 Inherits System.Windows.Forms.Form Public Sub New() MyBase.New() 'This call is required by the Windows Form Designer. InitializeComponent() 'Set the SystemEvents class to receive event notification 'when a user preference changes, the palette changes, or 'when display settings change. AddHandler SystemEvents.UserPreferenceChanging, _ AddressOf SystemEvents_UserPreferenceChanging AddHandler SystemEvents.PaletteChanged, _ AddressOf SystemEvents_PaletteChanged AddHandler SystemEvents.DisplaySettingsChanged, _ AddressOf SystemEvents_DisplaySettingsChanged End Sub 'Form overrides dispose to clean up the component list. Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean) If disposing Then If Not (components Is Nothing) Then components.Dispose() End If End If MyBase.Dispose(disposing) End Sub Private components As System.ComponentModel.IContainer <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent() Me.SuspendLayout() ' 'Form1 ' Me.ClientSize = New System.Drawing.Size(648, 398) Me.Name = "Form1" Me.Text = "Form1" Me.ResumeLayout(False) End Sub ' This method is called when a user preference changes. Private Sub SystemEvents_UserPreferenceChanging( _ ByVal sender As Object, _ ByVal e As UserPreferenceChangingEventArgs) MessageBox.Show("UserPreferenceChanging: " & _ e.Category.ToString()) End Sub ' This method is called when the palette changes. Private Sub SystemEvents_PaletteChanged( _ ByVal sender As Object, _ ByVal e As EventArgs) MessageBox.Show("PaletteChanged") End Sub ' This method is called when the display settings change. Private Sub SystemEvents_DisplaySettingsChanged( _ ByVal sender As Object, _ ByVal e As EventArgs) MessageBox.Show("The display settings changed.") End Sub End Class
Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.