Control.OnMouseHover(EventArgs) Methode

Definition

Löst das MouseHover-Ereignis aus.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)

Parameter

e
EventArgs

Ein EventArgs, das die Ereignisdaten enthält.An EventArgs that contains the event data.

Beispiele

Im folgenden Codebeispiel wird veranschaulicht, wie die Methoden OnMouseHover und OnMouseMove in einer abgeleiteten Klasse überschrieben werden.The following code example demonstrates how to override the OnMouseHover and OnMouseMove methods in a derived class. Um das Beispiel auszuführen, fügen Sie den folgenden Code in ein neues Formular ein, und fügen Sie diese Klasse, die dieselbe Datei bildet, nach dem Formular ein.To run the example, paste the following code in a new form and paste this class, forming the same file, after the form. Fügen Sie dem Formular eine Schaltfläche vom Typ FunButton hinzu.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

Hinweise

Durch das Auslösen eines Ereignisses wird der Ereignishandler über einen Delegaten aufgerufen.Raising an event invokes the event handler through a delegate. Weitere Informationen finden Sie unter Behandeln und Auslösen von Ereignissen.For more information, see Handling and Raising Events.

Mit der OnMouseHover-Methode können auch abgeleitete Klassen das Ereignis ohne Anfügen eines Delegaten behandeln.The OnMouseHover method also allows derived classes to handle the event without attaching a delegate. Dies ist das bevorzugte Verfahren für die Behandlung des Ereignisses in einer abgeleiteten Klasse.This is the preferred technique for handling the event in a derived class.

Hinweise für Vererber

Wenn Sie OnMouseHover(EventArgs) in einer abgeleiteten Klasse überschreiben, müssen Sie die OnMouseHover(EventArgs)-Methode der Basisklasse aufrufen, damit registrierte Delegaten das Ereignis empfangen.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.

Gilt für:

Siehe auch