Επεξεργασία

Κοινή χρήση μέσω

Form.OnClosed(EventArgs) Method

  • Reference

Definition

Namespace:
System.Windows.Forms
Assembly:
System.Windows.Forms.dll
Source:
Form.cs
Source:
Form.cs
Source:
Form.cs

Raises the Closed event.

protected:
 virtual void OnClosed(EventArgs ^ e);
protected virtual void OnClosed (EventArgs e);
abstract member OnClosed : EventArgs -> unit
override this.OnClosed : EventArgs -> unit
Protected Overridable Sub OnClosed (e As EventArgs)

Parameters

e
EventArgs

The EventArgs that contains the event data.

Examples

The following example demonstrates how to override the OnClosed method in a class derived from Form .

public ref class myForm: public Form
{
protected:
   virtual void OnClosed( EventArgs^ e ) override
   {
      MessageBox::Show( "The form is now closing.", "Close Warning", MessageBoxButtons::OK, MessageBoxIcon::Warning );
      Form::OnClosed( e );
   }

public:
   myForm()
      : Form()
   {}

};

public class myForm:
    Form

{
    protected override void OnClosed(EventArgs e)
    {
        MessageBox.Show("The form is now closing.", 
            "Close Warning", MessageBoxButtons.OK, MessageBoxIcon.Warning);
        base.OnClosed(e);
    }

    public myForm() : base()
    {        
    }
}

Public Class myForm
    Inherits Form

    Protected Overrides Sub OnClosed(ByVal e As EventArgs)
        MessageBox.Show("The form is now closing.", "Close Warning", _
            MessageBoxButtons.OK, MessageBoxIcon.Warning)
        MyBase.OnClosed(e)
    End Sub

    Public Sub New()
        MyBase.New()
    End Sub

End Class

Remarks

Caution

The OnClosed method is obsolete starting with the .NET Framework 2.0; use the OnFormClosed method instead.

Raising an event invokes the event handler through a delegate. For more information, see Handling and Raising Events.

The OnFormClosed 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.

Caution

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 OnClosed(EventArgs) in a derived class, be sure to call the base class's OnClosed(EventArgs) method so that registered delegates receive the event.

Applies to

See also