.NET MAUI Graphics Drawing

Use this skill when implementing custom drawing in .NET MAUI apps using Microsoft.Maui.Graphics and GraphicsView.

GraphicsView and IDrawable

GraphicsView is the canvas host control. Assign an IDrawable implementation to its Drawable property.

<GraphicsView Drawable="{StaticResource myDrawable}"
              HeightRequest="300"
              WidthRequest="300" />

public class MyDrawable : IDrawable
{
    public void Draw(ICanvas canvas, RectF dirtyRect)
    {
        // All drawing happens here
    }
}

• ICanvas provides all drawing methods.
• RectF dirtyRect is the area that needs redrawing.
• Call graphicsView.Invalidate() to trigger a redraw from outside the drawable.

Drawing Shapes

Lines

canvas.StrokeColor = Colors.Blue;
canvas.StrokeSize = 2;
canvas.DrawLine(10, 10, 200, 10);

Rectangles

canvas.StrokeColor = Colors.Black;
canvas.DrawRectangle(10, 10, 100, 50);
canvas.FillColor = Colors.LightBlue;
canvas.FillRectangle(10, 10, 100, 50);
canvas.DrawRoundedRectangle(10, 10, 100, 50, 12);
canvas.FillRoundedRectangle(10, 10, 100, 50, 12);

Ellipses

canvas.DrawEllipse(10, 10, 100, 80);
canvas.FillEllipse(10, 10, 100, 80);

Arcs

canvas.DrawArc(10, 10, 100, 100, 0, 180, clockwise: true, closed: false);

Paths with PathF

Use PathF for complex shapes built from segments.

var path = new PathF();
path.MoveTo(10, 10);
path.LineTo(100, 10);
path.LineTo(100, 100);
path.QuadTo(50, 150, 10, 100);   // control point, end point
path.CubicTo(0, 80, 0, 40, 10, 10); // cp1, cp2, end
path.Close();
canvas.StrokeColor = Colors.Red;
canvas.DrawPath(path);
canvas.FillColor = Colors.Orange;
canvas.FillPath(path);

• MoveTo(x, y) — move without drawing.
• LineTo(x, y) — straight line to point.
• QuadTo(cx, cy, x, y) — quadratic Bézier curve.
• CubicTo(c1x, c1y, c2x, c2y, x, y) — cubic Bézier curve.
• Close() — close the path back to the start.

Drawing Text

canvas.FontColor = Colors.Black;
canvas.FontSize = 18;
canvas.Font = Microsoft.Maui.Graphics.Font.Default;
// DrawString with bounding rect and alignment
canvas.DrawString("Hello", 10, 10, 200, 40,
    HorizontalAlignment.Center,
    VerticalAlignment.Center);

// DrawString at a point (no bounding box)
canvas.DrawString("World", 10, 60, HorizontalAlignment.Left);

• Set FontColor, FontSize, and Font before calling DrawString.
• Overloads accept either a point or a bounding rectangle with alignment.

Canvas State Properties

Set these properties before draw calls to control appearance.

Stroke

canvas.StrokeColor = Colors.Navy;
canvas.StrokeSize = 4;
canvas.StrokeDashPattern = new float[] { 6, 3 };     // dash, gap
canvas.StrokeLineCap = LineCap.Round;                 // Butt, Round, Square
canvas.StrokeLineJoin = LineJoin.Round;               // Miter, Round, Bevel
canvas.FillColor = Colors.CornflowerBlue;

Shadows

canvas.SetShadow(
    offset: new SizeF(5, 5),
    blur: 4,
    color: Colors.Gray);

canvas.FillRectangle(20, 20, 100, 60); // drawn with shadow
canvas.SetShadow(SizeF.Zero, 0, null); // remove shadow

Clipping

Restrict drawing to a region.

// Clip to rectangle
canvas.ClipRectangle(20, 20, 100, 100);
// Clip to arbitrary path
var clipPath = new PathF();
clipPath.AppendCircle(80, 80, 50);
canvas.ClipPath(clipPath);
// Subtract a region from the current clip
canvas.SubtractFromClip(40, 40, 30, 30);

Canvas State Management

Use SaveState / RestoreState to isolate drawing settings.

canvas.SaveState();
canvas.StrokeColor = Colors.Red;
canvas.StrokeSize = 6;
canvas.DrawRectangle(10, 10, 80, 80);
canvas.RestoreState();
// StrokeColor, StrokeSize, clip, shadow, etc. are restored

• Always pair SaveState and RestoreState.
• Saves/restores: stroke, fill, font, shadow, clip, and transforms.
• Nest calls for layered state isolation.

Triggering Redraws

graphicsView.Invalidate();

• Invalidate() queues a redraw; the framework calls IDrawable.Draw on the next frame.
• Do not call Draw directly; always use Invalidate().
• Avoid calling Invalidate() in a tight loop; batch state changes before invalidating.

Quick Reference

Method / Property	Purpose
DrawLine	Stroke a line between two points
DrawRectangle / FillRectangle	Stroke or fill a rectangle
DrawRoundedRectangle / FillRoundedRectangle	Rounded-corner rectangle
DrawEllipse / FillEllipse	Stroke or fill an ellipse
DrawArc	Stroke an arc segment
DrawPath / FillPath	Stroke or fill a PathF
DrawString	Render text with alignment
SetShadow	Apply drop shadow to subsequent draws
ClipRectangle / ClipPath	Restrict drawing region
SubtractFromClip	Remove area from clip
SaveState / RestoreState	Push/pop canvas state
graphicsView.Invalidate()	Request a redraw