Windows apps
Collapse the table of content
Expand the table of content
The topic you requested is included in another documentation set. For convenience, it's displayed below. Choose Switch to see the topic in its original location.

CancelEventArgs.Cancel Property

Gets or sets a value indicating whether the event should be canceled.

Namespace: System.ComponentModel
Assembly: System (in system.dll)

Public Property Cancel As Boolean
Dim instance As CancelEventArgs
Dim value As Boolean

value = instance.Cancel

instance.Cancel = value
/** @property */
public boolean get_Cancel ()

/** @property */
public void set_Cancel (boolean value)

public function get Cancel () : boolean

public function set Cancel (value : boolean)

Not applicable.

Property Value

true if the event should be canceled; otherwise, false.

The following example uses a CancelEventArgs and a CancelEventHandler to handle the Closing 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.")
        e.Cancel = False
    End If
End Sub 'Form1_Closing

// Calls this method from the InitializeComponent() method of your form
private void OtherInitialize()
    this.add_Closing(new CancelEventHandler(this.Form1_Cancel));
    this.myDataIsSaved = (boolean)new System.Boolean();
    this.myDataIsSaved = true;
} //OtherInitialize

protected void Form1_Cancel(Object sender, CancelEventArgs e)
    if (!(myDataIsSaved)) {
        MessageBox.Show("You must save first.");
    else {
} //Form1_Cancel

Windows 98, Windows Server 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 Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

XNA Framework

Supported in: 1.0

Community Additions

© 2017 Microsoft