利用RecyclerView实现一个非常简单的列表倒计时

一、先上效果图

二、GitHub

代码地址，欢迎指正https://github.com/MNXP/Countdown

三、思路

 在adapter中设置timer倒计时，然后利用RecyclerView更新单个item特性实现
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四、实现

1）变量

 useTime倒计时时间timeFlag用来判断是否有倒计时，倒计时结束更新UI
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2）倒计时

遍历list，设置时间useTime-1000，然后判断时间和timeFlag更新显示
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   private void startTime() {new Timer().schedule(new TimerTask() {@Overridepublic void run() {((Activity) mContext).runOnUiThread(new Runnable() {@Overridepublic void run() {for (int i = 0; i < mTimeDownBeanList.size(); i++) {long useTime = mTimeDownBeanList.get(i).getUseTime();if (useTime > 1000) {useTime -= 1000;mTimeDownBeanList.get(i).setUseTime(useTime);if (useTime <= 1000 && mTimeDownBeanList.get(i).isTimeFlag()) {mTimeDownBeanList.get(i).setTimeFlag(false);CountDownAdapter.this.notifyItemChanged(i);}else {mTimeDownBeanList.get(i).setTimeFlag(true);CountDownAdapter.this.notifyItemChanged(i);}}}}});}}, 0, 1000);}
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3）常规操作（设置倒计时时间）

  private void setTime(ViewHolder holder, int position) throws ParseException{TimeDownBean timeDownBean = mTimeDownBeanList.get(position);if (timeDownBean.getUseTime() > 1000) {holder.timeTv.setVisibility(View.VISIBLE);long useTime = timeDownBean.getUseTime();useTime = useTime / 1000;setTimeShow(useTime, holder);}else {holder.timeTv.setVisibility(View.GONE);}}private void setTimeShow(long useTime, ViewHolder holder) {int hour = (int) (useTime / 3600 );int min = (int) (useTime / 60 % 60);int second = (int) (useTime % 60);int day = (int) (useTime / 3600 / 24);String mDay, mHour, mMin, mSecond;//天，小时，分钟，秒second--;if (second < 0) {min--;second = 59;if (min < 0) {min = 59;hour--;}}if (hour < 10) {mHour = "0" + hour;} else {mHour = "" + hour;}if (min < 10) {mMin = "0" + min;} else {mMin = "" + min;}if (second < 10) {mSecond = "0" + second;} else {mSecond = "" + second;}String strTime = "上架倒计时 " +mHour + ":" + mMin + ":" + mSecond + "";holder.timeTv.setText(strTime);}
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4）注意

防止更新item时防止抖动
((SimpleItemAnimator) mRecycleListView.getItemAnimator()).setSupportsChangeAnimations(false);
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5）Adapter完整代码

public class CountDownAdapter extends RecyclerView.Adapter {private Context mContext;private List<TimeDownBean> mTimeDownBeanList;public CountDownAdapter(Context context,List<TimeDownBean> mTimeDownBeanList){this.mContext = context;this.mTimeDownBeanList = mTimeDownBeanList;startTime();}/*** 列表倒计时*/private void startTime() {new Timer().schedule(new TimerTask() {@Overridepublic void run() {((Activity) mContext).runOnUiThread(new Runnable() {@Overridepublic void run() {for (int i = 0; i < mTimeDownBeanList.size(); i++) {long useTime = mTimeDownBeanList.get(i).getUseTime();if (useTime > 1000) {useTime -= 1000;mTimeDownBeanList.get(i).setUseTime(useTime);if (useTime <= 1000 && mTimeDownBeanList.get(i).isTimeFlag()) {mTimeDownBeanList.get(i).setTimeFlag(false);CountDownAdapter.this.notifyItemChanged(i);}else {mTimeDownBeanList.get(i).setTimeFlag(true);CountDownAdapter.this.notifyItemChanged(i);}}}}});}}, 0, 1000);}@Overridepublic RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {View view = View.inflate(mContext,R.layout.count_down_item,null);return new ViewHolder(view);}@Overridepublic void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {if (holder instanceof ViewHolder){ViewHolder viewHolder = (ViewHolder) holder;TimeDownBean timeDownBean = mTimeDownBeanList.get(position);viewHolder.contentTv.setText(timeDownBean.getContent());try {setTime(viewHolder, position);} catch (ParseException e) {e.printStackTrace();}}}private void setTime(ViewHolder holder, int position) throws ParseException{TimeDownBean timeDownBean = mTimeDownBeanList.get(position);if (timeDownBean.getUseTime() > 1000) {holder.timeTv.setVisibility(View.VISIBLE);long useTime = timeDownBean.getUseTime();useTime = useTime / 1000;setTimeShow(useTime, holder);}else {holder.timeTv.setVisibility(View.GONE);}}private void setTimeShow(long useTime, ViewHolder holder) {int hour = (int) (useTime / 3600 );int min = (int) (useTime / 60 % 60);int second = (int) (useTime % 60);int day = (int) (useTime / 3600 / 24);String mDay, mHour, mMin, mSecond;//天，小时，分钟，秒second--;if (second < 0) {min--;second = 59;if (min < 0) {min = 59;hour--;}}if (hour < 10) {mHour = "0" + hour;} else {mHour = "" + hour;}if (min < 10) {mMin = "0" + min;} else {mMin = "" + min;}if (second < 10) {mSecond = "0" + second;} else {mSecond = "" + second;}String strTime = "上架倒计时 " +mHour + ":" + mMin + ":" + mSecond + "";holder.timeTv.setText(strTime);}@Overridepublic int getItemCount() {return mTimeDownBeanList!=null?mTimeDownBeanList.size():0;}private class ViewHolder extends RecyclerView.ViewHolder{private TextView contentTv;private TextView timeTv;private ViewHolder(View itemView) {super(itemView);init(itemView);itemView.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {if (itemClickListener!=null){itemClickListener.onItemClick(v,getLayoutPosition());}}});}private void init(View itemView) {contentTv = (TextView)itemView.findViewById(R.id.content_tv);timeTv = (TextView)itemView.findViewById(R.id.time_tv);}}//对外部暴漏点击事件接口public interface OnItemClickListener{void onItemClick(View v,int position);}public OnItemClickListener itemClickListener;public void setItemClickListener(OnItemClickListener itemClickListener) {this.itemClickListener = itemClickListener;}
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如有意见和建议，及时沟通。