（1）在MFC中用单文本框创建程序；

（2）创建菜单栏最重要是要有控制画线开始的 begin和画线结束的stop.

（3）在拖动屏幕的时候画的线仍然在而不是消失了。

（4）在菜单栏DrawLine 中选择的Begin 时开始画线命令，当线段的一端碰到系统指定的边框时自动向相反的方向画线；

（5）在选择Stop命令的时候画线停止，当选择 begin命令的时候继续画线。

（6）关键是在停止之后继续画线的时候线的起始坐标是停止时的，而不是最原始画线的坐标。

（7）画线过程中线的颜色随着时间在变化，长度也要在控制的范围内变化，画过的线能够保留并且可以覆盖，线与线之间存在适当的距离，以便观察起来视觉效果会好一点；

（8）最后选择菜单栏DrawLine 中的Stop 命令停止画线。

-1) with a single text box to create the program in MFC

(2) create the menu bar is the most important is to have the control line to begin and draw a line over stop.

(3) when dragging the screen painting line is still not disappeared.

(4) began to draw a line command option in the menu bar in DrawLine Begin, when the line is encountered the system specified frame automatically to draw a line in the opposite direction

(5) in the choice of painting line Stop command when to stop, continue to draw the line when you select the begin command.

(6) the key is the starting line coordinate time to draw lines on the stop after is stopped, not the original painting line coordinates.

(7) line drawing process of color change over time, length is changed in the control range, painted lines can be retained and can cover, there is a proper distance between the line and the line, in order to observe the visual effect will be better

(8) finally, select the menu bar in DrawLine Stop stop paintin