测量Android中两个MotionEvent之间的经过时间

Question

我是Android编程的新手,所以我在问题上请求你的帮助.我试图以秒/毫秒为单位测量MouseEvent.ACTION_DOWN和MouseEvent.ACTION_UP之间的时间.

@Override
public boolean onTouchEvent(MotionEvent event) {
    long start=0;
    if (event.getAction() == MotionEvent.ACTION_DOWN) {
        // manage down press
        start=System.nanoTime();//START
        System.out.println("START");
    }
    else if (event.getAction() == MotionEvent.ACTION_MOVE) {
        // manage move
        System.out.println(event.getRawX()+","+event.getRawY());
    }
    else {
        // manage up
        long finish=System.nanoTime()//FINISH
        long seconds = (finish-start) / 1000000000;//for seconds
        Toast.makeText(this, "FINISH, duration: "+seconds, Toast.LENGTH_SHORT).show();
        System.out.println("FINISH, duration: "+seconds);
    }
    return true;
}




Logcat:
03-19 04:04:27.140: I/System.out(4348): START
03-19 04:04:27.160: I/System.out(4348): 517.0,280.0
03-19 04:04:27.190: I/System.out(4348): 517.0,280.0
03-19 04:04:27.200: I/System.out(4348): 517.0,280.0
03-19 04:04:27.220: I/System.out(4348): 517.0,280.0
03-19 04:04:27.250: I/System.out(4348): 517.0,280.0
03-19 04:04:27.260: I/System.out(4348): 517.0,280.0
03-19 04:04:27.300: I/System.out(4348): 517.0,280.0
03-19 04:04:27.310: I/System.out(4348): 517.0,280.0
03-19 04:04:27.330: I/System.out(4348): FINISH, duration: 16545

我的问题实际上是秒变量没有显示我想要的东西,我甚至不知道它的测量是否正确.对于上面的例子,持续时间是16545(???!？!？)但是它应该在1之间-3秒.我应该怎么做才能在几秒或几毫秒内正确测量两个MotionEvent之间的时间或我的例子中的错误？谢谢 !

Answer 1

long startTime;
public boolean onTouchEvent(MotionEvent event) {

    if (event.getAction() == MotionEvent.ACTION_DOWN) 
        startTime = System.nanoTime();    

    else if (event.getAction() == MotionEvent.ACTION_UP) {
        long elapseTime = System.nanoTime() - startTime;
        //do whatever u want with elapseTime now, its in nanoseconds
    }
}

Answer 2

A MotionEvent有时间戳.使用getEventTime()访问它.

事实上,由于不能保证MotionEvent被立即传送到你的代码,这个时间戳比你得到任何时候更加准确System.getCurrentTimeMillis().