if wanted create form drawing area in traditional windows form, extend panel class , override onpaint method custom drawing, so: public class specialpanel : system.windows.forms.panel { protected override void onpaint(painteventargs e) { graphics g = e.graphics; g.drawellipse(new pen(color.red), 50, 80, 50, 10); } } but in wpf if attempt extend canvas class there no onpaint method override public class specialcanvas : canvas //error no onpaint method { public override onpaint(painteventargs e) { } } if wanted draw canvas in way similar this: canvas.setleft(shape.shape, r.next(1, 1150)); canvas.settop(shape.shape, r.next(1, 500)); solidcolorbrush b = new solidcolorbrush(windows.ui.color.fromargb(255, (byte)r.next(1, 255), (byte)r.next(1, 255), (byte)r.next(1, 255))); shape.shape.fill = b; shape.shape.stroke = b; cann.children.add(shape.shape); where cann canvas object , shape.shape...