在Android的开发中,我们经常遇见倒计时的操作,通常使用Timer和Handler共同操作来完成。当然也可以使用Android系统控件CountDownTimer,这里我们封装成一个控件,也方便大家的使用。
首先上一张效果图吧:
说一下造成卡顿的原因,由于滑动的时候,adapter的getView频繁的创建和销毁,就会出现卡顿和数据错位问题,那么我们每一个item的倒计时就需要单独维护,这里我用的Handler与timer及TimerTask结合的方法,我们知道TimerTask运行在自己子线程,然后通过Timer的schedule()方法实现倒计时功能,最后通过Hander实现View的刷新,其核心代码如下:
public class CountDownView extends LinearLayout { @BindView(R.id.tv_day) TextView tvDay; @BindView(R.id.tv_hour) TextView tvHour; @BindView(R.id.tv_minute) TextView tvMinute; @BindView(R.id.tv_second) TextView tvSecond; @BindView(R.id.day) TextView day; @BindView(R.id.hour) TextView hour; @BindView(R.id.minute) TextView minute; private Context context; private int viewBg;//倒计时的背景 private int cellBg;//每个倒计时的背景 private int cellTextColor;//文字颜色 private int textColor;//外部:等颜色 private int textSize = 14;//外部文字大小 private int cellTextSize = 12;//cell文字大小 private TimerTask timerTask = null; private Timer timer = new Timer(); private Handler handler = new Handler() { public void handleMessage(Message msg) { countDown(); } }; public CountDownView(Context context, AttributeSet attrs) { this(context, attrs, 0); this.context = context; } public CountDownView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); this.context = context; initAttrs(attrs, defStyleAttr); initView(context); } private void initAttrs(AttributeSet attrs, int defStyle) { TypedArray typedArray = getContext().obtainStyledAttributes(attrs, R.styleable.CountDownView, defStyle,0); viewBg = typedArray.getColor(R.styleable.CountDownView_viewBg, Color.parseColor("#FFFFFF")); cellBg = typedArray.getColor(R.styleable.CountDownView_cellBg, Color.parseColor("#F4F4F4")); cellTextColor = typedArray.getColor(R.styleable.CountDownView_cellTextColor, Color.parseColor("#646464")); textColor = typedArray.getColor(R.styleable.CountDownView_TextColor, Color.parseColor("#B3B3B3")); textSize = (int) typedArray.getDimension(R.styleable.CountDownView_TextSize, UIUtils.dp2px(getContext(), 14)); cellTextSize = (int) typedArray.getDimension(R.styleable.CountDownView_cellTextSize, UIUtils.dp2px(getContext(), 12)); typedArray.recycle(); } private void initView(Context context) { LayoutInflater inflater = (LayoutInflater) context .getSystemService(Context.LAYOUT_INFLATER_SERVICE); View view = inflater.inflate(R.layout.layout_countdown_layout, this); ButterKnife.bind(view); initProperty(); } private void initProperty() { tvDay.setBackgroundColor(cellBg); tvHour.setBackgroundColor(cellBg); tvMinute.setBackgroundColor(cellBg); tvSecond.setBackgroundColor(cellBg); tvDay.setTextColor(cellTextColor); tvHour.setTextColor(cellTextColor); tvMinute.setTextColor(cellTextColor); tvSecond.setTextColor(cellTextColor); day.setTextColor(textColor); hour.setTextColor(textColor); minute.setTextColor(textColor); } public void setLeftTime(long leftTime) { if (leftTime <= 0) return; long time = leftTime / 1000; long day = time / (3600 * 24); long hours = (time - day * 3600 * 24) / 3600; long minutes = (time - day * 3600 * 24 - hours * 3600) / 60; long seconds = time - day * 3600 * 24 - hours * 3600 - minutes * 60; setTextTime(time); } public void start() { if (timerTask == null) { timerTask = new TimerTask() { @Override public void run() { handler.sendEmptyMessage(0); } }; timer.schedule(timerTask, 1000, 1000); // timer.schedule(new TimerTask() { // @Override // public void run() { // handler.sendEmptyMessage(0); // } // }, 0, 1000); } } public void stop() { if (timer != null) { timer.cancel(); timer = null; } } //保证天,时,分,秒都两位显示,不足的补0 private void setTextTime(long time) { String[] s = TimeUtils.formatTimer(time); tvDay.setText(s[0]); tvHour.setText(s[1]); tvMinute.setText(s[2]); tvSecond.setText(s[3]); } private void countDown() { if (isCarry4Unit(tvSecond)) { if (isCarry4Unit(tvMinute)) { if (isCarry4Unit(tvHour)) { if (isCarry4Unit(tvDay)) { stop(); } } } } } private boolean isCarry4Unit(TextView tv) { int time = Integer.valueOf(tv.getText().toString()); time = time - 1; if (time < 0) { time = 59; tv.setText(time + ""); return true; } else if (time < 10) { tv.setText("0" + time); return false; } else { tv.setText(time + ""); return false; } } }
另一种写法:
public class CountDownTimerView extends LinearLayout { private TextView hourView, minuteView, secondView; private LimitTimer mTimer; private Handler handler; public static final int START_LIMIT_TIME_MSG = 0x0111; public static final int END_LIMIT_TIME_MSG = 0x0112; private long endTime, leftTime; private LimitTimeListener listener=null; public CountDownTimerView(Context context) { super(context); initView(context); } public CountDownTimerView(Context context, AttributeSet attrs) { super(context, attrs); initView(context); } private void initView(Context context) { setOrientation(HORIZONTAL); setGravity(Gravity.CENTER_VERTICAL); inflate(context, R.layout.layout_countdown_layout, this); hourView = (TextView) findViewById(R.id.tv_hour); minuteView = (TextView) findViewById(R.id.tv_minute); secondView = (TextView) findViewById(R.id.tv_second); } public long getLeftTime() { return leftTime; } //设置剩余时间 public void initLeftTime(long endTime) { endTime=endTime*1000; if (null != mTimer) { mTimer.cancel(); mTimer = null; } this.endTime = endTime; mTimer = new LimitTimer(endTime, 1000); mTimer.start(); if (handler != null) { handler.sendEmptyMessage(START_LIMIT_TIME_MSG); } } /** * 如果该控件使用在碎片中,返回时,则最好还是要stop */ public void stopTimeCount() { if (null != mTimer) { mTimer.cancel(); mTimer = null; } } public Handler getHandler() { return handler; } public void setHandler(Handler handler) { this.handler = handler; } private class LimitTimer extends CountDownTimer { public LimitTimer(long millisInFuture, long countDownInterval) { super(0 != leftTime ? leftTime : endTime, countDownInterval); } @Override public void onTick(long millisUntilFinished) { leftTime = millisUntilFinished; long totalSecond = millisUntilFinished / 1000; int second = (int) (totalSecond % 60); int minute = (int) ((totalSecond / 60) % 60); int hour = (int) ((totalSecond / 3600) % 24); int day = (int) (totalSecond / (3600 * 24)); formatView(hourView, hour); formatView(minuteView, minute); formatView(secondView, second); } @Override public void onFinish() { String zero = "00"; hourView.setText(zero); minuteView.setText(zero); secondView.setText(zero); if (null != handler) { handler.sendEmptyMessage(END_LIMIT_TIME_MSG); } if (listener!=null){ listener.onTimeOver(true); } } private void formatView(TextView view, int time) { DecimalFormat df = new DecimalFormat("#00"); view.setText(df.format(time)); } } //倒计时结束监听 public void setOnLimitTimeListener(LimitTimeListener listener) { this.listener = listener; } public interface LimitTimeListener { void onTimeOver(boolean flag); } @Override protected void onDetachedFromWindow() { super.onDetachedFromWindow(); if (handler != null) { handler.removeMessages(START_LIMIT_TIME_MSG); } } }
涉及到的布局文件
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以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持脚本之家。