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
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
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
private void startTime() {
new Timer().schedule(new TimerTask() {
@Override
public void run() {
((Activity) mContext).runOnUiThread(new Runnable() {
@Override
public 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);
}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);
}4）注意
防止更新item时防止抖动
((SimpleItemAnimator) mRecycleListView.getItemAnimator()).setSupportsChangeAnimations(false);
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() {
@Override
public void run() {
((Activity) mContext).runOnUiThread(new Runnable() {
@Override
public 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);
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = View.inflate(mContext,R.layout.count_down_item,null);
return new ViewHolder(view);
}
@Override
public 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);
}
@Override
public 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() {
@Override
public 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;
}
}
如有意见和建议，及时沟通。