此程序实现了全局鼠标钩子，其他钩子也可如法炮制，还实现了一个圆形的透明窗口用于动态显示当前系统时间，并且始终跟随鼠标。-this program achieved the global mouse hook, the hook has other wineries. also achieving a circular transparent window for the dynamic display of the current system time, and always follow t

通过鼠标钩子勾住鼠标所在位置控件，获取该控件的句柄。(Through the mouse hook to hook the mouse position control, access to the handle of the control.)