ToolStripRenderer Klasse

Definition

public ref class ToolStripRenderer abstract

public abstract class ToolStripRenderer

type ToolStripRenderer = class

Public MustInherit Class ToolStripRenderer

Vererbung

Object

ToolStripRenderer

Abgeleitet

System.Windows.Forms.ToolStripProfessionalRenderer

System.Windows.Forms.ToolStripSystemRenderer

Beispiele

Im folgenden Codebeispiel wird veranschaulicht, wie eine benutzerdefinierte ToolStripRenderer-Klasse implementiert wird. Die GridStripRenderer -Klasse passt drei Aspekte der Darstellung des GridStrip Steuerelements an: GridStrip Rahmen, ToolStripButton Rahmen und ToolStripButton Bild. Eine vollständige Codeauflistung finden Sie unter Vorgehensweise: Implementieren eines benutzerdefinierten ToolStripRenderers.

// This class implements a custom ToolStripRenderer for the 
// GridStrip control. It customizes three aspects of the 
// GridStrip control's appearance: GridStrip border, 
// ToolStripButton border, and ToolStripButton image.
internal class GridStripRenderer : ToolStripRenderer
{   
    // The style of the empty cell's text.
    private static StringFormat style = new StringFormat();

    // The thickness (width or height) of a 
    // ToolStripButton control's border.
    static int borderThickness = 2;

    // The main bitmap that is the source for the 
    // subimagesthat are assigned to individual 
    // ToolStripButton controls.
    private Bitmap bmp = null;

    // The brush that paints the background of 
    // the GridStrip control.
    private Brush backgroundBrush = null;

    // This is the static constructor. It initializes the
    // StringFormat for drawing the text in the empty cell.
    static GridStripRenderer()
    {
        style.Alignment = StringAlignment.Center;
        style.LineAlignment = StringAlignment.Center;
    }

    // This method initializes the GridStripRenderer by
    // creating the image that is used as the source for
    // the individual button images.
    protected override void Initialize(ToolStrip ts)
    {
        base.Initialize(ts);

        this.InitializeBitmap(ts);
    }

    // This method initializes an individual ToolStripButton
    // control. It copies a subimage from the GridStripRenderer's
    // main image, according to the position and size of 
    // the ToolStripButton.
    protected override void InitializeItem(ToolStripItem item)
    {
        base.InitializeItem(item);

        GridStrip gs = item.Owner as GridStrip;

        // The empty cell does not receive a subimage.
        if ((item is ToolStripButton) &&
            (item != gs.EmptyCell))
        {
            // Copy the subimage from the appropriate 
            // part of the main image.
            Bitmap subImage = bmp.Clone(
                item.Bounds,
                PixelFormat.Undefined);

            // Assign the subimage to the ToolStripButton
            // control's Image property.
            item.Image = subImage;
        }
    }

    // This utility method creates the main image that
    // is the source for the subimages of the individual 
    // ToolStripButton controls.
    private void InitializeBitmap(ToolStrip toolStrip)
    {
        // Create the main bitmap, into which the image is drawn.
        this.bmp = new Bitmap(
            toolStrip.Size.Width,
            toolStrip.Size.Height);

        // Draw a fancy pattern. This could be any image or drawing.
        using (Graphics g = Graphics.FromImage(bmp))
        {
            // Draw smoothed lines.
            g.SmoothingMode = SmoothingMode.AntiAlias;
            
            // Draw the image. In this case, it is 
            // a number of concentric ellipses. 
            for (int i = 0; i < toolStrip.Size.Width; i += 8)
            {
                g.DrawEllipse(Pens.Blue, 0, 0, i, i);
            }
        }
    }

    // This method draws a border around the GridStrip control.
    protected override void OnRenderToolStripBorder(
        ToolStripRenderEventArgs e)
    {
        base.OnRenderToolStripBorder(e);

        ControlPaint.DrawFocusRectangle(
            e.Graphics,
            e.AffectedBounds,
            SystemColors.ControlDarkDark,
            SystemColors.ControlDarkDark);
    }

    // This method renders the GridStrip control's background.
    protected override void OnRenderToolStripBackground(
        ToolStripRenderEventArgs e)
    {
        base.OnRenderToolStripBackground(e);

        // This late initialization is a workaround. The gradient
        // depends on the bounds of the GridStrip control. The bounds 
        // are dependent on the layout engine, which hasn't fully
        // performed layout by the time the Initialize method runs.
        if (this.backgroundBrush == null)
        {
            this.backgroundBrush = new LinearGradientBrush(
               e.ToolStrip.ClientRectangle,
               SystemColors.ControlLightLight,
               SystemColors.ControlDark,
               90,
               true);
        }

        // Paint the GridStrip control's background.
        e.Graphics.FillRectangle(
            this.backgroundBrush, 
            e.AffectedBounds);
    }

    // This method draws a border around the button's image. If the background
    // to be rendered belongs to the empty cell, a string is drawn. Otherwise,
    // a border is drawn at the edges of the button.
    protected override void OnRenderButtonBackground(
        ToolStripItemRenderEventArgs e)
    {
        base.OnRenderButtonBackground(e);

        // Define some local variables for convenience.
        Graphics g = e.Graphics;
        GridStrip gs = e.ToolStrip as GridStrip;
        ToolStripButton gsb = e.Item as ToolStripButton;

        // Calculate the rectangle around which the border is painted.
        Rectangle imageRectangle = new Rectangle(
            borderThickness, 
            borderThickness, 
            e.Item.Width - 2 * borderThickness, 
            e.Item.Height - 2 * borderThickness);

        // If rendering the empty cell background, draw an 
        // explanatory string, centered in the ToolStripButton.
        if (gsb == gs.EmptyCell)
        {
            e.Graphics.DrawString(
                "Drag to here",
                gsb.Font, 
                SystemBrushes.ControlDarkDark,
                imageRectangle, style);
        }
        else
        {
            // If the button can be a drag source, paint its border red.
            // otherwise, paint its border a dark color.
            Brush b = gs.IsValidDragSource(gsb) ? b = 
                Brushes.Red : SystemBrushes.ControlDarkDark;

            // Draw the top segment of the border.
            Rectangle borderSegment = new Rectangle(
                0, 
                0, 
                e.Item.Width, 
                imageRectangle.Top);
            g.FillRectangle(b, borderSegment);

            // Draw the right segment.
            borderSegment = new Rectangle(
                imageRectangle.Right,
                0,
                e.Item.Bounds.Right - imageRectangle.Right,
                imageRectangle.Bottom);
            g.FillRectangle(b, borderSegment);

            // Draw the left segment.
            borderSegment = new Rectangle(
                0,
                0,
                imageRectangle.Left,
                e.Item.Height);
            g.FillRectangle(b, borderSegment);

            // Draw the bottom segment.
            borderSegment = new Rectangle(
                0,
                imageRectangle.Bottom,
                e.Item.Width,
                e.Item.Bounds.Bottom - imageRectangle.Bottom);
            g.FillRectangle(b, borderSegment);
        }
    }
}

' This class implements a custom ToolStripRenderer for the 
' GridStrip control. It customizes three aspects of the 
' GridStrip control's appearance: GridStrip border, 
' ToolStripButton border, and ToolStripButton image.
Friend Class GridStripRenderer
     Inherits ToolStripRenderer

   ' The style of the empty cell's text.
   Private Shared style As New StringFormat()
   
   ' The thickness (width or height) of a 
   ' ToolStripButton control's border.
   Private Shared borderThickness As Integer = 2
   
   ' The main bitmap that is the source for the 
   ' subimagesthat are assigned to individual 
   ' ToolStripButton controls.
   Private bmp As Bitmap = Nothing
   
   ' The brush that paints the background of 
   ' the GridStrip control.
   Private backgroundBrush As Brush = Nothing
   
   
   ' This is the static constructor. It initializes the
   ' StringFormat for drawing the text in the empty cell.
   Shared Sub New()
      style.Alignment = StringAlignment.Center
      style.LineAlignment = StringAlignment.Center
   End Sub 
   
   ' This method initializes the GridStripRenderer by
   ' creating the image that is used as the source for
   ' the individual button images.
   Protected Overrides Sub Initialize(ts As ToolStrip)
      MyBase.Initialize(ts)
      
      Me.InitializeBitmap(ts)
     End Sub

   ' This method initializes an individual ToolStripButton
   ' control. It copies a subimage from the GridStripRenderer's
   ' main image, according to the position and size of 
   ' the ToolStripButton.
   Protected Overrides Sub InitializeItem(item As ToolStripItem)
      MyBase.InitializeItem(item)
      
         Dim gs As GridStrip = item.Owner
      
      ' The empty cell does not receive a subimage.
         If ((TypeOf (item) Is ToolStripButton) And _
              (item IsNot gs.EmptyCell)) Then
             ' Copy the subimage from the appropriate 
             ' part of the main image.
             Dim subImage As Bitmap = bmp.Clone(item.Bounds, PixelFormat.Undefined)

             ' Assign the subimage to the ToolStripButton
             ' control's Image property.
             item.Image = subImage
         End If
   End Sub 

   ' This utility method creates the main image that
   ' is the source for the subimages of the individual 
   ' ToolStripButton controls.
   Private Sub InitializeBitmap(toolStrip As ToolStrip)
      ' Create the main bitmap, into which the image is drawn.
      Me.bmp = New Bitmap(toolStrip.Size.Width, toolStrip.Size.Height)
      
      ' Draw a fancy pattern. This could be any image or drawing.
      Dim g As Graphics = Graphics.FromImage(bmp)
      Try
         ' Draw smoothed lines.
         g.SmoothingMode = SmoothingMode.AntiAlias
         
         ' Draw the image. In this case, it is 
         ' a number of concentric ellipses. 
         Dim i As Integer
         For i = 0 To toolStrip.Size.Width - 8 Step 8
            g.DrawEllipse(Pens.Blue, 0, 0, i, i)
         Next i
      Finally
         g.Dispose()
      End Try
   End Sub 
   
   ' This method draws a border around the GridStrip control.
   Protected Overrides Sub OnRenderToolStripBorder(e As ToolStripRenderEventArgs)
      MyBase.OnRenderToolStripBorder(e)
      
      ControlPaint.DrawFocusRectangle(e.Graphics, e.AffectedBounds, SystemColors.ControlDarkDark, SystemColors.ControlDarkDark)
   End Sub 

   ' This method renders the GridStrip control's background.
   Protected Overrides Sub OnRenderToolStripBackground(e As ToolStripRenderEventArgs)
      MyBase.OnRenderToolStripBackground(e)
      
      ' This late initialization is a workaround. The gradient
      ' depends on the bounds of the GridStrip control. The bounds 
      ' are dependent on the layout engine, which hasn't fully
      ' performed layout by the time the Initialize method runs.
      If Me.backgroundBrush Is Nothing Then
         Me.backgroundBrush = New LinearGradientBrush(e.ToolStrip.ClientRectangle, SystemColors.ControlLightLight, SystemColors.ControlDark, 90, True)
      End If
      
      ' Paint the GridStrip control's background.
      e.Graphics.FillRectangle(Me.backgroundBrush, e.AffectedBounds)
     End Sub

   ' This method draws a border around the button's image. If the background
   ' to be rendered belongs to the empty cell, a string is drawn. Otherwise,
   ' a border is drawn at the edges of the button.
   Protected Overrides Sub OnRenderButtonBackground(e As ToolStripItemRenderEventArgs)
      MyBase.OnRenderButtonBackground(e)
      
      ' Define some local variables for convenience.
      Dim g As Graphics = e.Graphics
      Dim gs As GridStrip = e.ToolStrip 
      Dim gsb As ToolStripButton = e.Item 
      
      ' Calculate the rectangle around which the border is painted.
      Dim imageRectangle As New Rectangle(borderThickness, borderThickness, e.Item.Width - 2 * borderThickness, e.Item.Height - 2 * borderThickness)
      
      ' If rendering the empty cell background, draw an 
      ' explanatory string, centered in the ToolStripButton.
         If gsb Is gs.EmptyCell Then
             e.Graphics.DrawString("Drag to here", gsb.Font, SystemBrushes.ControlDarkDark, imageRectangle, style)
         Else
             ' If the button can be a drag source, paint its border red.
             ' otherwise, paint its border a dark color.
             Dim b As Brush = IIf(gs.IsValidDragSource(gsb), Brushes.Red, SystemBrushes.ControlDarkDark)

             ' Draw the top segment of the border.
             Dim borderSegment As New Rectangle(0, 0, e.Item.Width, imageRectangle.Top)
             g.FillRectangle(b, borderSegment)

             ' Draw the right segment.
             borderSegment = New Rectangle(imageRectangle.Right, 0, e.Item.Bounds.Right - imageRectangle.Right, imageRectangle.Bottom)
             g.FillRectangle(b, borderSegment)

             ' Draw the left segment.
             borderSegment = New Rectangle(0, 0, imageRectangle.Left, e.Item.Height)
             g.FillRectangle(b, borderSegment)

             ' Draw the bottom segment.
             borderSegment = New Rectangle(0, imageRectangle.Bottom, e.Item.Width, e.Item.Bounds.Bottom - imageRectangle.Bottom)
             g.FillRectangle(b, borderSegment)
         End If
     End Sub
 End Class

Hinweise

Verwenden Sie die ToolStripRenderer -Klasse, um einen bestimmten Stil oder ein bestimmtes Design auf anzuwenden ToolStrip. Anstatt eine ToolStrip und die ToolStripItem darin enthaltenen Objekte benutzerdefinierte zu zeichnen, legen Sie die ToolStrip.Renderer -Eigenschaft auf ein -Objekt fest, das von ToolStripRenderererbt. Die von ToolStripRenderer angegebene Zeichnung wird auf die ToolStripangewendet, sowie auf die darin enthaltenen Elemente.

Sie können auf verschiedene Weise in ToolStrip-Steuerelementen zeichnen. Wie bei anderen Windows Forms-Steuerelementen besitzen auch ToolStrip und ToolStripItem überschreibbare OnPaint-Methoden und Paint-Ereignisse. Wie beim normalen Zeichnen ist das Koordinatensystem relativ zum Clientbereich des Steuerelements, d. h. die linke obere Ecke des Steuerelements ist 0, 0. Das Paint-Ereignis und die OnPaint-Methode für ein ToolStripItem verhalten sich wie andere Ereignisse zum Zeichnen von Steuerelementen.

Die ToolStripRenderer -Klasse verfügt über überschreibbare Methoden zum Zeichnen des Hintergrunds, des Elementhintergrunds, des Elementbilds, des Elementpfeils, des Elementtexts und des ToolStripRahmens von . Die Ereignisargumente für diese Methoden zeigen verschiedene Eigenschaften wie Rechtecke, Farben und Textformate an, die Sie nach Belieben anpassen können.

Wenn Sie nur einige Aspekte anpassen möchten, wie ein Element gezeichnet wird, setzen Sie in der Regel die Option ToolStripRenderer außer Kraft.

Wenn Sie ein neues Element erstellen und alle Aspekte des Bilds steuern möchten, setzen Sie die Methode OnPaint außer Kraft. Sie können aus OnPaint heraus Methoden von ToolStripRenderer verwenden.

Standardmäßig wird ToolStrip doppelt gepuffert und nutzt die Einstellung OptimizedDoubleBuffer.

Konstruktoren

Felder

Methoden

Ereignisse

Gilt für:

Weitere Informationen

• MenuStrip
• StatusStrip
• ToolStripProfessionalRenderer
• ToolStripSystemRenderer
• Vorgehensweise: Implementieren eines benutzerdefinierten ToolStripRenderer