java - 如何暂停和恢复倒计时器？

Question

我的游戏 Activity 中有一个倒计时器，当我接到来电或某些 Activity 失去焦点时，我需要暂停它。我尝试这样做，但它不起作用(onPause方法有效，它停止计时器，但不会恢复它):

private long total = 180000;

MyCount brojacVremena = new MyCount(total, 1000);

public class MyCount extends CountDownTimer {

        public MyCount(long millisInFuture, long countDownInterval) {
            super(millisInFuture, countDownInterval);
        }

        @Override
        public void onFinish() {


        @Override
        public void onTick(long millisUntilFinished) {
            total = millisUntilFinished;
            vreme.setText("" + millisUntilFinished / 1000);

        }
        }

@Override
    protected void onResume() {
        // TODO Auto-generated method stub
        super.onResume();
        MyCount brojacVremena = new MyCount(total, 1000);
        brojacVremena.start();
    }

@Override
protected void onPause() {
    // TODO Auto-generated method stub
    super.onPause();
    brojacVremena.cancel();
}

我什至在 onPause 中尝试过这个:

@Override
    protected void onPause() {
        // TODO Auto-generated method stub
        super.onPause();
        MyCount brojacVremenaNew = new MyCount(total, 1000);
        brojacVremenaNew.cancel();
}

Answer 1

我认为您不需要扩展它，除非确实有必要。我赞同 codeMagic 所说的 - 将剩余时间存储在 onPause() 中的变量中，并且不要忘记将其保存在 onSaveInstanceState() 中或到SharedPreference。

当您的 Activity 恢复时，无论是由于配置更改还是其他原因，您可以重新创建计时器:

new CountDownTimer(millisUntilFinished, tickTime) {

     public void onTick(long millisUntilFinished) {
         millisUntilFinished -= tickTime;
         // do you wanna know for whom the bell tolls?
     }

     public void onFinish() {
         // it tolls for thee
         millisUntilFinished = 0;
     }
  }.start();  

在 onPause() 中取消此计时器，并在 onResume() 中根据剩余时间创建一个新的计时器实例:)

编辑:像这样的事情:

@Override
public void onResume(){
    super.onResume();
    millisUntilFinished = getMillisFromSharedPreference(KEY);
    if(millisUntilFinished != 0){
        new CountDownTimer(millisUntilFinished, tickTime) {

         public void onTick(long millisUntilFinished) {
             millisUntilFinished -= tickTime;
             // do you wanna know for whom the bell tolls?
         }

         public void onFinish() {
             // it tolls for thee
             millisUntilFinished = 0;
         }
        }.start();
    }
}

@Override
public void onPause(){
    super.onPause();
    saveMillisToSharedPreference(KEY,millisUntilFinished);
}