Gets or sets a value indicating whether the event should be canceled.
Assembly: System (in System.dll)
The following example uses CancelEventArgs and a CancelEventHandler to handle the FormClosing event of a Form. This code assumes that you have created a Form with a class-level Boolean variable named isDataSaved. It also assumes that you have added a statement to invoke the OtherInitialize method from the form's Load method or the constructor (after the call to InitializeComponent).
' Call this method from the Load method of your form. Private Sub OtherInitialize() ' Exchange commented line and note the difference. Me.isDataSaved = True 'Me.isDataSaved = False End Sub 'OtherInitialize Private Sub Form1_Closing(sender As Object, e As _ System.ComponentModel.CancelEventArgs) Handles MyBase.Closing If Not isDataSaved Then e.Cancel = True MessageBox.Show("You must save first.") Else e.Cancel = False MessageBox.Show("Goodbye.") End If End Sub 'Form1_Closing
.NET FrameworkSupported in: 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0
.NET Framework Client ProfileSupported in: 4, 3.5 SP1
Portable Class LibrarySupported in: Portable Class Library
.NET for Windows Store appsSupported in: Windows 8
.NET for Windows Phone appsSupported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8
Windows Phone 8.1, Windows Phone 8, 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.