画直线

1.以鼠标左键的按下为 起点 ,保持按下状态,移动鼠标,直到放开鼠标键作为 终点 ,画一条静态直线.

2.在鼠标移动过程中应该从 起点 向鼠标的 当前位置 画一条动态的直线.绘制动态直线的方法是,先删除前一条直线,然后画一条新的直线.在鼠标移动过程中会不断接收到许多WM_MOUSEMOVE消息,其中LOWORD(lParam)和HIWORD(lParam)分别存放鼠标的当前X,Y值.

-1. draw a straight line with the left mouse button pressed for the " starting point" , keep it pressed, move the mouse until you release the mouse button as the " destination" , draw a straight line static. 2. In the process of moving the mouse should be　the " starting point " to the mouse,"　draw a dynamic linear current location. " draw dynamic linear approach is a straight line before the first remove, and then draw a new line. in the mouse to move the process will continue to receive many WM_MOUSEMOVE message, which LOWORD ( lParam) and HIWORD (lParam) were stored the mouse' s current X, Y values.