Control.OnMouseHover(EventArgs) Control.OnMouseHover(EventArgs) Control.OnMouseHover(EventArgs) Control.OnMouseHover(EventArgs) Method

Definizione

Genera l'evento MouseHover.Raises the MouseHover event.

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

Parametri

e
EventArgs EventArgs EventArgs EventArgs

Oggetto EventArgs che contiene i dati dell'evento.An EventArgs that contains the event data.

Esempi

Esempio di codice seguente viene illustrato come eseguire l'override di OnMouseHover e OnMouseMove metodi in una classe derivata.The following code example demonstrates how to override the OnMouseHover and OnMouseMove methods in a derived class. Per eseguire l'esempio, incollare il codice seguente in un nuovo modulo e incollare questa classe, che costituiscono lo stesso file, dopo la forma.To run the example, paste the following code in a new form and paste this class, forming the same file, after the form. Aggiungere un pulsante di tipo FunButton al form.Add a button of type FunButton to the form.

// To use this example create a new form and paste this class 
// forming the same file, after the form class in the same file.  
// Add a button of type FunButton to the form. 
public ref class FunButton: public Button
{
protected:
   virtual void OnMouseHover( System::EventArgs^ e ) override
   {
      
      // Get the font size in Points, add one to the
      // size, and reset the button's font to the larger
      // size.
      float fontSize = Font->SizeInPoints;
      fontSize += 1;
      System::Drawing::Size buttonSize = Size;
      this->Font = gcnew System::Drawing::Font( Font->FontFamily,fontSize,Font->Style );
      
      // Increase the size width and height of the button 
      // by 5 points each.
      Size = System::Drawing::Size( Size.Width + 5, Size.Height + 5 );
      
      // Call myBase.OnMouseHover to activate the delegate.
      Button::OnMouseHover( e );
   }

   virtual void OnMouseMove( MouseEventArgs^ e ) override
   {
      
      // Make the cursor the Hand cursor when the mouse moves 
      // over the button.
      Cursor = Cursors::Hand;
      
      // Call MyBase.OnMouseMove to activate the delegate.
      Button::OnMouseMove( e );
   }
public class FunButton:
	Button

{
	protected override void OnMouseHover(System.EventArgs e)
	{

		// Get the font size in Points, add one to the
		// size, and reset the button's font to the larger
		// size.
		float fontSize = Font.SizeInPoints;
		fontSize += 1;
		System.Drawing.Size buttonSize = Size;
		this.Font = new System.Drawing.Font(
			Font.FontFamily, fontSize, Font.Style);

		// Increase the size width and height of the button 
		// by 5 points each.
		Size = new System.Drawing.Size(Size.Width+5, Size.Height+5);

		// Call myBase.OnMouseHover to activate the delegate.
		base.OnMouseHover(e);
	}

	protected override void OnMouseMove(MouseEventArgs e)
	{

		// Make the cursor the Hand cursor when the mouse moves 
		// over the button.
		Cursor = Cursors.Hand;

		// Call MyBase.OnMouseMove to activate the delegate.
		base.OnMouseMove(e);
	}
Public Class FunButton
    Inherits Button

    Protected Overrides Sub OnMouseHover(ByVal e As System.EventArgs)

        ' Get the font size in Points, add one to the
        ' size, and reset the button's font to the larger
        ' size.
        Dim fontSize As Single = Font.SizeInPoints
        fontSize += 1
        Dim buttonSize As System.Drawing.Size = Size
        Me.Font = New System.Drawing.Font _
            (Font.FontFamily, fontSize, Font.Style)

        ' Increase the size width and height of the button 
        ' by 5 points each.
        Size = New System.Drawing.Size _
            (Size.Width + 5, Size.Height + 5)

        ' Call myBase.OnMouseHover to activate the delegate.
        MyBase.OnMouseHover(e)
    End Sub

    Protected Overrides Sub OnMouseMove(ByVal e As MouseEventArgs)

        ' Make the cursor the Hand cursor when the mouse moves 
        ' over the button.
        Cursor = Cursors.Hand

        ' Call MyBase.OnMouseMove to activate the delegate.
        MyBase.OnMouseMove(e)
    End Sub

Commenti

Quando viene generato un evento, il gestore dell'evento viene richiamato tramite un delegato.Raising an event invokes the event handler through a delegate. Per altre informazioni, vedere la gestione e generazione di eventi.For more information, see Handling and Raising Events.

Il metodo OnMouseHover consente inoltre alle classi derivate di gestire l'evento senza associare un delegato.The OnMouseHover method also allows derived classes to handle the event without attaching a delegate. È la tecnica consigliata per la gestione dell'evento in una classe derivata.This is the preferred technique for handling the event in a derived class.

Note per gli eredi

Quando si esegue l'override di OnMouseHover(EventArgs) in una classe derivata, verificare di chiamare il metodo OnMouseHover(EventArgs) della classe di base in modo che i delegati registrati ricevano l'evento.When overriding OnMouseHover(EventArgs) in a derived class, be sure to call the base class's OnMouseHover(EventArgs) method so that registered delegates receive the event.

Si applica a

Vedi anche