在Picturebox中的C＃内绘图

I want to be able to allow users of my program to click on a button, for example, a button for freehand rectangles to be drawn onto a picturebox. I need code for allowing me to first draw on the picturebox, and secondly for all the shapes that can possibly be drawn free hand in c#, e.g. line, ellipse, freehand drawing, text.I want to be able to allow users of my program