ToolStripItem.OnPaint(PaintEventArgs) Méthode

protected:
 virtual void OnPaint(System::Windows::Forms::PaintEventArgs ^ e);

protected virtual void OnPaint(System.Windows.Forms.PaintEventArgs e);

abstract member OnPaint : System.Windows.Forms.PaintEventArgs -> unit
override this.OnPaint : System.Windows.Forms.PaintEventArgs -> unit

Protected Overridable Sub OnPaint (e As PaintEventArgs)

Paramètres

Exemples

L’exemple de code suivant montre comment remplacer la méthode pour le OnPaint rendu personnalisé. Cet exemple de code fait partie d’un exemple plus grand fourni pour la ToolStripItem classe.

// This method defines the painting behavior of the control.
// It performs the following operations:
//
// Computes the layout of the item's image and text.
// Draws the item's background image.
// Draws the item's image.
// Draws the item's text.
//
// Drawing operations are implemented in the 
// RolloverItemRenderer class.
protected override void OnPaint(PaintEventArgs e)
{
    base.OnPaint(e);

    if (this.Owner != null)
    {
        // Find the dimensions of the image and the text 
        // areas of the item. 
        this.ComputeImageAndTextLayout();

        // Draw the background. This includes drawing a highlighted 
        // border when the mouse is in the client area.
        ToolStripItemRenderEventArgs ea = new ToolStripItemRenderEventArgs(
             e.Graphics,
             this);
        this.Owner.Renderer.DrawItemBackground(ea);

        // Draw the item's image. 
        ToolStripItemImageRenderEventArgs irea =
            new ToolStripItemImageRenderEventArgs(
            e.Graphics,
            this,
            imageRect );
        this.Owner.Renderer.DrawItemImage(irea);

        // If the item is on a drop-down, give its
        // text a different highlighted color.
        Color highlightColor = 
            this.IsOnDropDown ?
            Color.Salmon : SystemColors.ControlLightLight;

        // Draw the text, and highlight it if the 
        // the rollover state is true.
        ToolStripItemTextRenderEventArgs rea =
            new ToolStripItemTextRenderEventArgs(
            e.Graphics,
            this,
            base.Text,
            textRect,
            this.rolloverValue ? highlightColor : base.ForeColor,
            base.Font,
            base.TextAlign);
        this.Owner.Renderer.DrawItemText(rea);
    }
}

' This method defines the painting behavior of the control.
' It performs the following operations:
'
' Computes the layout of the item's image and text.
' Draws the item's background image.
' Draws the item's image.
' Draws the item's text.
'
' Drawing operations are implemented in the 
' RolloverItemRenderer class.
Protected Overrides Sub OnPaint(e As PaintEventArgs)
   MyBase.OnPaint(e)
   
   If (Me.Owner IsNot Nothing) Then
      ' Find the dimensions of the image and the text 
      ' areas of the item. 
      Me.ComputeImageAndTextLayout()
      
      ' Draw the background. This includes drawing a highlighted 
      ' border when the mouse is in the client area.
      Dim ea As New ToolStripItemRenderEventArgs(e.Graphics, Me)
      Me.Owner.Renderer.DrawItemBackground(ea)
      
      ' Draw the item's image. 
      Dim irea As New ToolStripItemImageRenderEventArgs(e.Graphics, Me, imageRect)
      Me.Owner.Renderer.DrawItemImage(irea)
      
      ' If the item is on a drop-down, give its
      ' text a different highlighted color.
         Dim highlightColor As Color = CType(IIf(Me.IsOnDropDown, Color.Salmon, SystemColors.ControlLightLight), Color)
      
      ' Draw the text, and highlight it if the 
      ' the rollover state is true.
         Dim rea As New ToolStripItemTextRenderEventArgs( _
            e.Graphics, _
            Me, _
            MyBase.Text, _
            textRect, _
            CType(IIf(Me.rolloverValue, highlightColor, MyBase.ForeColor), Color), _
            MyBase.Font, _
            MyBase.TextAlign)
      Me.Owner.Renderer.DrawItemText(rea)
   End If
 End Sub

Remarques

Le déclenchement d’un événement appelle le gestionnaire d’événements par le biais d’un délégué. Pour plus d’informations, consultez Gestion et déclenchement d’événements.

La OnPaint méthode permet également aux classes dérivées de gérer l’événement sans attacher de délégué. Il s’agit de la technique recommandée pour gérer l’événement dans une classe dérivée.

Notes pour les héritiers

En cas de OnPaint(PaintEventArgs) substitution dans une classe dérivée, veillez à appeler la méthode de la classe de OnPaint(PaintEventArgs) base afin que les délégués inscrits reçoivent l’événement.