Android将倒计时做到极致

r囧r小猫 2023-10-03 20:27 12阅读 0赞

public class CountDownTimer {
    
        private int mTimes;
        private int allTimes;
        private final long mCountDownInterval;
        private final Handler mHandler;
        private OnTimerCallBack mCallBack;
        private boolean isStart;
        private long startTime;
    
        public CountDownTimer(int times, long countDownInterval){
            this.mTimes = times;
            this.mCountDownInterval = countDownInterval;
            mHandler = new Handler();
        }
    
        public synchronized void start(OnTimerCallBack callBack){
            this.mCallBack = callBack;
            if (isStart || mCountDownInterval <= 0){
                return;
            }
    
            isStart = true;
            if (callBack != null){
                callBack.onStart();
            }
            startTime = SystemClock.elapsedRealtime();
    
            if (mTimes <= 0){
                finishCountDown();
                return;
            }
            allTimes = mTimes;
    
            mHandler.postDelayed(runnable, mCountDownInterval);
        }
    
        private final Runnable runnable = new Runnable() {
            @Override
            public void run() {
                mTimes--;
                if (mTimes > 0){
                    if (mCallBack != null){
                        mCallBack.onTick(mTimes);
                    }
    
                    long nowTime = SystemClock.elapsedRealtime();
                    long delay = (nowTime - startTime) - (allTimes - mTimes) * mCountDownInterval;
                    // 处理跳秒
                    while (delay > mCountDownInterval){
                        mTimes --;
                        if (mCallBack != null){
                            mCallBack.onTick(mTimes);
                        }
    
                        delay -= mCountDownInterval;
                        if (mTimes <= 0){
                            finishCountDown();
                            return;
                        }
                    }
    
                    mHandler.postDelayed(this, 1000 - delay);
                }else {
                    finishCountDown();
                }
            }
        };
    
        private void finishCountDown(){
            if (mCallBack != null){
                mCallBack.onFinish();
            }
            isStart = false;
        }
    
        public void cancel(){
            mHandler.removeCallbacksAndMessages(null);
            isStart = false;
        }
    
        public interface OnTimerCallBack{
    
            void onStart();
    
            void onTick(int times);
    
            void onFinish();
    
        }
    
    }

[Android将倒计时做到极致 - 掘金][Android_ -]

[Android_ -]: https://juejin.cn/post/7140652166980567076#heading-1