Raises the Closing event.
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
The method is obsolete in the .NET Framework version 2.0; use the OnFormClosing method instead.
Raising an event invokes the event handler through a delegate. For more information, see Raising an Event.
The method also allows derived classes to handle the event without attaching a delegate. Overriding this method is the preferred technique for handling the event in a derived class.
The OnClosed and methods are not called when the Application.Exit method is called to exit your application. If you have validation code in either of these methods that must be executed, you should call the Form.Close method for each open form individually before calling the Exit method.
When overriding in a derived class, be sure to call the base class's method so that registered delegates receive the event.
Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.