创建一个vi，实现对按钮状态的指示和按钮“按下”持续时间的简单计算功能，按下按钮时，对应的指示灯亮，对应的数字量显示控件中开始计时。松开按钮时，指示灯灭，计时停止。(Create a VI to realize the instructions of the button state and the simple computing function of the button "press" the duration. When the button is pressed, the corresponding indicator lights up, and the corresponding digital quantity displays the timing in the control. When the button is loosened, the light is put out and the timing is stopped.)