java - 测量 Android 中两个 MotionEvents 之间耗时

Question

我是 Android 编程的新手，所以我请求您帮助解决我的问题。我正在尝试以秒/毫秒为单位测量 MouseEvent.ACTION_DOWN 和 MouseEvent.ACTION_UP 之间的时间量。

@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

My problem consist in fact that seconds variable doesn't show what I want, I even don't know if its measuring correctly.For the above example duration was 16545 (???!?!?) but it should have been between 1-3 seconds.What shall I do to measure correctly in seconds or milliseconds the time between two MotionEvents or what am I wrong in my example ? Thank you !

Answer 1

MotionEvent 有一个时间戳。使用 getEventTime() 访问它。

事实上，由于无法保证 MotionEvent 会立即传送到您的代码，因此此时间戳比您从 System.getCurrentTimeMillis() 获得的任何时间都更准确>.