Assembly: System.Windows.Forms (in system.windows.forms.dll)
The OnClick method changes the CheckState property. If the ThreeState property is set to true, subsequent clicks of the CheckBox will result in OnClick cycling through all the values of the CheckState enumeration. Otherwise, OnClick switches between Checked and Unchecked.
Raising an event invokes the event handler through a delegate. For more information, see Raising an Event.
The OnClick method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.Notes to Inheritors When overriding OnClick in a derived class, be sure to call the base class’s OnClick method so that registered delegates receive the event.
Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, 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.