.NET Framework 4.5.2+
.NET Framework 4.5.2+
.NET Standard 2.0+

BeforePagePaintEventArgs.Canvas Property

Provides access to layout drawing surface.

Namespace: DevExpress.XtraRichEdit

Assembly: DevExpress.RichEdit.v21.1.Core.dll

Declaration

public PageCanvas Canvas { get; }

Property Value

Type Description
PageCanvas

A PageCanvas object which encapsulates the layout drawing surface.

Remarks

Use the Canvas property to access methods for drawing objects on the document layout.

Example

This code snippet illustrates the implementation of a PagePainter descendant. It draws color rectangles in place of the words and labels a floating picture with a text string drawn over it.

public class MyLayoutPainter : PagePainter
{
    public override void DrawPlainTextBox(PlainTextBox plainTextBox)
    {
        if (Form1.customDrawText == true)
        {
            Canvas.DrawRectangle(new RichEditPen(Color.FromArgb(141, 179, 226)), plainTextBox.Bounds);
        }
        else base.DrawPlainTextBox(plainTextBox);
    }

    public override void DrawFloatingPicture(LayoutFloatingPicture floatingPicture)
    {
        if (Form1.customDrawImage == true)
        {
            Rectangle bounds = floatingPicture.Bounds;
            Point startPoint = new Point(bounds.X + Canvas.ConvertToDrawingLayoutUnits(10, DocumentLayoutUnit.Pixel), bounds.Y + bounds.Height - Canvas.ConvertToDrawingLayoutUnits(40, DocumentLayoutUnit.Pixel));
            RichEditPen pEn = new RichEditPen(Color.Coral);
            pEn.Thickness = 30;
            pEn.DashStyle = RichEditDashStyle.Dash;
            Canvas.DrawEllipse(pEn, bounds);
            Canvas.DrawString("Approved", new Font("Courier New", 26), new RichEditBrush(Color.DarkMagenta), startPoint);
        }
        else
            base.DrawFloatingPicture(floatingPicture);
    }

    public override void DrawTableCell(LayoutTableCell tableCell)
    {
        if (Form1.customDrawTable == true)
        {
            Rectangle Tbounds = tableCell.Bounds;

            int x = Tbounds.X + Tbounds.Width/2 - Canvas.ConvertToDrawingLayoutUnits(20, DocumentLayoutUnit.Pixel);
            int y = Tbounds.Y + Tbounds.Height/2 - Canvas.ConvertToDrawingLayoutUnits(20, DocumentLayoutUnit.Pixel);
            Rectangle tableRectangle = new Rectangle(x,y, Canvas.ConvertToDrawingLayoutUnits(20, DocumentLayoutUnit.Pixel), 
                Canvas.ConvertToDrawingLayoutUnits(20, DocumentLayoutUnit.Pixel));

            Canvas.FillEllipse(new RichEditBrush(Color.MediumAquamarine), tableRectangle);
            base.DrawTableCell(tableCell);
        }
        else
            base.DrawTableCell(tableCell);
    }

   public override void DrawInlineDrawingObject(InlineDrawingObjectBox inlinePictureBox)
    {
        if (Form1.customDrawPicture == true)
        {
            Rectangle Ebounds = inlinePictureBox.Bounds;
            RichEditPen pen = new RichEditPen(Color.Maroon, 50);
            pen.DashStyle = RichEditDashStyle.Dot;
            Canvas.DrawLine(pen, new Point(Ebounds.X, Ebounds.Y + Ebounds.Height), new Point(Ebounds.X + Ebounds.Width, Ebounds.Y));
            Canvas.DrawLine(pen, new Point(Ebounds.X, Ebounds.Y), new Point(Ebounds.X + Ebounds.Width, Ebounds.Y + Ebounds.Height));
            Rectangle inlineRect = new Rectangle(Ebounds.X, Ebounds.Y, Ebounds.Width, Ebounds.Height);
            Canvas.DrawRectangle(new RichEditPen(Color.Aquamarine, 40), inlineRect);
        }
        else
            base.DrawInlineDrawingObject(inlinePictureBox);
    }

    public override void DrawTextBox(LayoutTextBox textBox)
    {
        if (Form1.customDrawTextBox == true)
        {
            Point[] StarPoints =
                {
            new Point(textBox.Bounds.X+textBox.Bounds.Width/2,textBox.Bounds.Y),
            new Point(textBox.Bounds.X+textBox.Bounds.Width,textBox.Bounds.Y+textBox.Bounds.Height),
            new Point(textBox.Bounds.X,textBox.Bounds.Y+textBox.Bounds.Height/2),
            new Point(textBox.Bounds.X+textBox.Bounds.Width,textBox.Bounds.Y+textBox.Bounds.Height/2),
            new Point(textBox.Bounds.X,textBox.Bounds.Y+textBox.Bounds.Height),
            new Point(textBox.Bounds.X+textBox.Bounds.Width/2,textBox.Bounds.Y)
                };
            Canvas.DrawLines(new RichEditPen(Color.HotPink, 30), StarPoints);
        }
        else
            base.DrawTextBox(textBox);
    }

    public override void DrawNumberingListWithSeparatorBox(NumberingListWithSeparatorBox numberingListWithSeparatorBox)
    {
        if (Form1.customDrawSeparator == true) Canvas.FillRectangle(new RichEditBrush(Color.DarkRed), numberingListWithSeparatorBox.Bounds);
        else base.DrawNumberingListWithSeparatorBox(numberingListWithSeparatorBox);
    }

    public override void DrawPage(LayoutPage page)
    {
        if (Form1.customDrawPage == true)
        {
            Rectangle inlineRect = new Rectangle(100, 100, 150, 200);
            Canvas.DrawRectangle(new RichEditPen(Color.Aquamarine, Canvas.ConvertToDrawingLayoutUnits(4, DocumentLayoutUnit.Pixel)), Canvas.ConvertToDrawingLayoutUnits(inlineRect, DocumentLayoutUnit.Pixel));

        }
        base.DrawPage(page);
    }
}
See Also