如何在android中每次按键使用dispatchKeyEvent调用按键？答案

【问题标题】：how to call key press using dispatchKeyEvent once per key press in android?如何在android中每次按键使用dispatchKeyEvent调用按键？
【发布时间】：2021-10-11 09:23:34
【问题描述】：

在下面的代码中，每次按下键码 144 时，我想在按键向下和向上之间的时间差大于 1000 毫秒时执行一些功能。但是我注意到，当 keydown 超过 100 毫秒左右时，它会继续重复调用 keydown，而不是等待 keyup 侦听器并最终计算差异，因为它计算与上次 keydown 时间的差异。如何以这样一种方式进行编程，即监听器应该只调用一次按键，直到触发kep up事件

@覆盖 public boolean dispatchKeyEvent(KeyEvent event) {

         long diff=0;

        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                down = System.currentTimeMillis();
                Log.e("current_down",String.valueOf((down)));

                break;
            case MotionEvent.ACTION_UP:
                Log.e("current_down2",String.valueOf((down)));

                //this is the time in milliseconds
                diff = (System.currentTimeMillis()- down);
               


                break;
        }

        int keyCode = event.getKeyCode();
        Log.e("javan",String.valueOf((keyCode)));





        if (event.getAction() == KeyEvent.ACTION_UP && keyCode == 144) {


          if(diff >1000){


            //do something 

  }
        }

【问题讨论】：

标签： java android keypress

【解决方案1】：

long diff = 0; // these two values should be declared at the start of the
long down = 0; // method
switch (event.getAction()) {
    case MotionEvent.ACTION_DOWN:
        if(down == 0) {
            down = System.currentTimeMillis(); // save current time if nothing is saved
            Log.e("current_down",String.valueOf((down)));
        }
        break;
    case MotionEvent.ACTION_UP:
        Log.e("current_down2",String.valueOf((down)));

        //this is the time in milliseconds
        diff = (System.currentTimeMillis()- down);
        down = 0; // if you need the value of down afterwards, 
                  // you can create another variable and save it there,
                  // this should be reset to 0 after action up for your case
}

现在，当然还有其他方法，但我想不到这个。

【讨论】：