ToolStripRenderer Classe

Definizione

public ref class ToolStripRenderer abstract

public abstract class ToolStripRenderer

type ToolStripRenderer = class

Public MustInherit Class ToolStripRenderer

Ereditarietà

Object

ToolStripRenderer

Derivato

System.Windows.Forms.ToolStripProfessionalRenderer

System.Windows.Forms.ToolStripSystemRenderer

Esempio

L'esempio di codice seguente illustra come implementare una classe ToolStripRenderer personalizzata. La GridStripRenderer classe personalizza tre aspetti dell'aspetto GridStrip del controllo: GridStrip bordo, ToolStripButton bordo e ToolStripButton immagine. Per un elenco di codice completo, vedere Procedura: Implementare un oggetto ToolStripRenderer personalizzato.

// 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

Commenti

Utilizzare la ToolStripRenderer classe per applicare uno stile o un tema specifico a un oggetto ToolStrip. Anziché disegnare un ToolStrip oggetto e gli ToolStripItem oggetti contenuti, impostare la ToolStrip.Renderer proprietà su un oggetto che eredita da ToolStripRenderer. Il disegno specificato da ToolStripRenderer viene applicato a ToolStrip, nonché agli elementi in esso contenuti.

È possibile eseguire un disegno personalizzato nei ToolStrip controlli in diversi modi. Come per altri controlli Windows Forms, e hanno sia metodi che Paint eventi di cui è possibile eseguire l'override ToolStripOnPaint.ToolStripItem Come nel quadro regolare, il sistema di coordinate è relativo all'area client del controllo; ovvero, l'angolo superiore sinistro del controllo è 0, 0. L'evento e OnPaint il Paint metodo per un ToolStripItem comportamento simile ad altri eventi di disegno del controllo.

La ToolStripRenderer classe include metodi sottoponibili a override per disegnare lo sfondo, lo sfondo dell'elemento, l'immagine dell'elemento, la freccia dell'elemento, il testo dell'elemento e il bordo dell'oggetto ToolStrip. Gli argomenti dell'evento per questi metodi espongono diverse proprietà, ad esempio rettangoli, colori e formati di testo che è possibile modificare in base alle esigenze.

Per regolare solo alcuni aspetti del modo in cui viene disegnato un elemento, in genere si esegue l'override di ToolStripRenderer.

Se si scrive un nuovo elemento e si desidera controllare tutti gli aspetti del disegno, eseguire l'override del OnPaint metodo . Dall'interno OnPaintdi è possibile usare i metodi di ToolStripRenderer.

Per impostazione predefinita, viene ToolStrip eseguito il doppio buffer, sfruttando l'impostazione OptimizedDoubleBuffer .

Costruttori

Campi

Metodi

Eventi

Si applica a

Vedi anche

• MenuStrip
• StatusStrip
• ToolStripProfessionalRenderer
• ToolStripSystemRenderer
• Procedura: Implementare un oggetto ToolStripRenderer personalizzato