Form.OnClosing Method (CancelEventArgs)

 
System_CAPS_noteNote

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Raises the Closing event.

Namespace:   System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

abstract OnClosing : 
        e:CancelEventArgs -> unit
override OnClosing : 
        e:CancelEventArgs -> unit

Parameters

e
Type: System.ComponentModel.CancelEventArgs

A CancelEventArgs that contains the event data.

System_CAPS_cautionCaution

The OnClosing method is obsolete in the .NET Framework version 2.0; use the OnFormClosing method instead.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 Handling and Raising Events.

The OnClosing 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.

System_CAPS_cautionCaution

The OnClosed and OnClosing 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.

Notes to Inheritors:

When overriding OnClosing in a derived class, be sure to call the base class's OnClosing method so that registered delegates receive the event.

The following code example uses Closing to test if the text in a TextBox has changed. If it has, the user is asked whether to save the changes to a file.

No code example is currently available or this language may not be supported.

.NET Framework
Available since 1.1
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