c# - How to find draw on System.Windows.Controls.*? -

i'm digging in wpf application written in c#.
need draw selection rectangle, 1 use select more 1 item (like files in folder).
have few objects, of types system.windows.controls.control, system.windows.controls.contentcontrol , system.windows.frameworkelement.
assume, need override event onpaint, ondraw or redraw/repaint.

can use object draw rectangle , how?

wpf , winforms different aspect. in winforms can override onpaint draw directly drawing context using graphics object in event handler.

in wpf, there onrender method, seemingly behaves onpaint:

protected override void onrender(drawingcontext dc) {     solidcolorbrush mysolidcolorbrush  = new solidcolorbrush();     mysolidcolorbrush.color = colors.limegreen;     pen mypen = new pen(brushes.blue, 10);     rect myrect = new rect(0, 0, 500, 500);     dc.drawrectangle(mysolidcolorbrush, mypen, myrect); } 

however, in wpf every visual element object, cannot draw directly anything. "drawing" methods of drawingcontext do, inserting objects visual tree, rendered later along other elements.

using onrender not best idea, , has really bad performance comparing fast graphics operations. in wpf better use custom controls or templates instead.