Form.Deactivate Event


Occurs when an active form becomes inactive. This API is obsolete. For information about how to develop ASP.NET mobile applications, see Mobile Apps & Sites with ASP.NET.

 event EventHandler ^ Deactivate;
public event EventHandler Deactivate;
member this.Deactivate : EventHandler 
Public Custom Event Deactivate As EventHandler 


The following code example demonstrates how to trap the Deactivate event to clear the SelectionList. This example is part of a larger example for the Form overview.

// When Form1 is deactivated
private void Form1_Deactivate(object sender, EventArgs e)
' When Form1 is deactivated
Private Sub Form1_Deactivate(ByVal sender As Object, _
    ByVal e As EventArgs)

    count += 1
End Sub


A form becomes inactive under the following circumstances:

  • When the ActiveForm property of the page is programmatically set to another form.

  • When the user navigates to a form through a Link control whose target is a form.

If neither of these actions occurs, the active form will never receive a Deactivate event. This event's position in the event chain makes it very important in resetting the child controls, data set, or global variables.

Applies to

See also