Introduction - If you have any usage issues, please Google them yourself
Design a simple MFC program, which position the mouse left click to draw a rectangle, rectangle size is random. Design: (1) in a program to define a rectangular array, used to store a randomly generated rectangle. (2) to the mouse click position as the center, random function rand () produces a number of side length generates a rectangle and rectangle stored in a rectangular array. (3) and then generates a WM_PAINT message, and in the corresponding message handler redraw all the rectangles in the array. (Source code for a very complete notes to facilitate readers to understand the program)