Android 列表倒计时的实现的示例代码（CountDownTimer）

  private CountDownTimer timer = new CountDownTimer(30000, 1000) { 
    //根据间隔时间来不断回调此方法，这里是每隔1000ms调用一次
    @Override 
    public void onTick(long millisUntilFinished) { 
      //todo millisUntilFinished为剩余时间，也就是30000 - n*1000
    } 
    
    //结束倒计时调用  
    @Override 
    public void onFinish() { 
      //todo
    } 
}; 

//开始倒计时
timer.start();

//取消倒计时（译者：取消后，再次启动会重新开始倒计时）
timer.cancel();;

class CountDownAdapter(private var activity: ListActivity, private var data: ArrayList<Date , private var systemDate: Date) : BaseAdapter() {
private val timeMap = HashMap<TextView, MyCountDownTimer ()
private val handler = Handler()
private val runnable = object : Runnable {
override fun run() {
if (systemDate != null) {
systemDate.time = systemDate.time + 1000
Log.i("xujf", "服务器时间线程===" + systemDate + "==for==" + this)
handler.postDelayed(this, 1000)
}
}
}
init {
handler.postDelayed(runnable, 1000)
}
override fun getView(position: Int, convertView: View?, parent: ViewGroup?): View {
var v: View
var tag: ViewHolder
var vo = data[position]
if (null == convertView) {
v = activity.layoutInflater.inflate(R.layout.item_count_down, null)
tag = ViewHolder(v)
v.tag = tag
} else {
v = convertView
tag = v.tag as ViewHolder
}
//获取控件对应的倒计时控件是否存在, 存在就取消, 解决时间重叠问题
var tc: MyCountDownTimer? = timeMap[tag.tvTime]
if (tc != null) {
tc.cancel()
tc = null
}
//计算时间差
val time = getDistanceTimeLong(systemDate, vo)
//创建倒计时，与控件绑定
val cdu = MyCountDownTimer(position, time, 1000, tag.tvTime)
cdu.start()
//[醒目]此处需要map集合将控件和倒计时类关联起来
timeMap.put(tag.tvTime, cdu)
return v
}
/**
* 退出时清空所有item的计时器
*/
fun cancelAllTimers() {
var s: Set<MutableMap.MutableEntry<TextView, MyCountDownTimer  ? = timeMap.entries
var it: Iterator<* ? = s!!.iterator()
while (it!!.hasNext()) {
try {
val pairs = it.next() as MutableMap.MutableEntry<*, * 
var cdt: MyCountDownTimer? = pairs.value as MyCountDownTimer
cdt!!.cancel()
cdt = null
} catch (e: Exception) {
}
}
it = null
s = null
timeMap.clear()
}
fun removeTimer(){
handler?.removeCallbacks(runnable)
}
fun reSetTimer(date: Date) {
removeTimer()
systemDate = date
handler.postDelayed(runnable, 1000)
}
override fun getItem(position: Int): Any = data[position]
override fun getItemId(position: Int): Long = 0L
override fun getCount(): Int = data.size
internal inner class ViewHolder(view: View) {
var tvTime = view.findViewById<TextView (R.id.tv_time)
}
/**
* 倒计时类，每间隔countDownInterval时间调用一次onTick()
* index参数可去除，在这里只是为了打印log查看倒计时是否运行
*/
private inner class MyCountDownTimer(internal var index: Int, millisInFuture: Long,
internal var countDownInterval: Long, internal var tv: TextView
) : CountDownTimer(millisInFuture, countDownInterval) {
override fun onTick(millisUntilFinished: Long) {
//millisUntilFinished为剩余时间长
Log.i("xujf", "====倒计时还活着===第 $index 项item======")
//设置时间格式
val m = millisUntilFinished / countDownInterval
val hour = m / (60 * 60)
val minute = (m / 60) % 60
val s = m % 60
tv.text = "倒计时 (${hour}小时${minute}分${s}秒)"
}
override fun onFinish() {
tv.text = "倒计时结束"
//todo 可以做一些刷新动作
}
}
/**
* 时间工具，返回间隔时间长
*/
fun getDistanceTimeLong(one: Date, two: Date): Long {
var diff = 0L
try {
val time1 = one.time
val time2 = two.time
if (time1 < time2) {
diff = time2 - time1
} else {
diff = time1 - time2
}
} catch (e: Exception) {
e.printStackTrace()
}
return diff
}
}

class ListActivity : AppCompatActivity() {
private val list: ArrayList<Date  = ArrayList()
private var countDownAdapter: CountDownAdapter? = null
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_list)
getDate()
setDate()
}
private fun setDate() {
if (countDownAdapter == null) {
countDownAdapter = CountDownAdapter(this, list, Date())
lv_count_down.adapter = countDownAdapter
lv_count_down.onItemClickListener = AdapterView.OnItemClickListener { adapterView, view, i, l - 
val intent = Intent(ListActivity@this, Main2Activity::class.java)
startActivity(intent)
}
} else {
//刷新数据时，重置本地服务器时间
countDownAdapter!!.reSetTimer(Date())
countDownAdapter!!.notifyDataSetChanged()
}
}
private fun getDate() {
for (i in 1..20) {
var date = Date(Date().time + i * 1000 * 60 * 30)
list.add(date)
}
}
override fun onDestroy() {
countDownAdapter?.cancelAllTimers()
countDownAdapter?.removeTimer()
super.onDestroy()
}
}

countDownAdapter?.cancelAllTimers()
countDownAdapter?.removeTimer()