参见;

Control.Paint Event（System.Windows.Forms） [ ^ ]



在Paint事件处理程序中绘制C＃ - C＃HelperC＃Helper [ ^ ]



c＃ - 在mou上绘制一个矩形se click - Stack Overflow [ ^ ]

Draw like app Paint in our computer. Please help me :(  

What I have tried:

Draw like app Paint in our computer. Please help me :(  

See;
Control.Paint Event (System.Windows.Forms)[^]

Draw in a Paint event handler in C# - C# HelperC# Helper[^]

c# - Draw a rectangle on mouse click - Stack Overflow[^]