在RecyclerView中设置计数器 [英] Set counter inside RecyclerView
本文介绍了在RecyclerView中设置计数器的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我有倒数计时器，如下图所示:
现在这些计时器将开始在每个项目中递减计数，我尝试了多次以更改我的Adapter计时器，但它不起作用，这是我的代码:
公共类AdapterItems扩展了RecyclerView.Adapter {
private ArrayList<TopCompetitions> mListItems = new ArrayList<>();
private ImageLoader mImageLoader;
private Context context;
private Handler handler;
/******************************************/
String current_date = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date());
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Date d1 = null;
Date d2 = null;
long diff;
long diffSeconds;
long diffMinutes;
long diffHours;
long diffDays;
String reachableDate = "";
/******************************************/
private ScheduledFuture updateFuture;
public AdapterItems(Context context) {
this.context = context;
mImageLoader = AppController.getInstance().getImageLoader();
}
public void setmListItems(ArrayList<TopCompetitions> mListItems) {
this.mListItems = mListItems;
//update the adapter to reflect the new set of mListItems
notifyDataSetChanged();
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.
from(parent.getContext()).
inflate(R.layout.custom_horizontal_row, parent, false);
return new ItemHolder(itemView);
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
final TopCompetitions currentItem = mListItems.get(position);
final ItemHolder itemHolder = (ItemHolder) holder;
/* start_date , name_com_ar , name_com_en,
question_en,answer_ar1,answer_ar2,answer_ar3
,answer_en1,answer_en2,answer_en3,right_answer;
*/
itemHolder.item_id.setText(currentItem.getPrize_id());
itemHolder.item_description.setText(currentItem.getName_com_ar());
itemHolder.start_date.setText(currentItem.getStart_date());
itemHolder.end_date.setText(currentItem.getEnd_date());
itemHolder.name_com_ar.setText(currentItem.getName_com_ar());
itemHolder.name_com_en.setText(currentItem.getName_com_en());
itemHolder.answer_en1.setText(currentItem.getAnswer_en1());
itemHolder.answer_en2.setText(currentItem.getAnswer_en2());
itemHolder.answer_en3.setText(currentItem.getAnswer_en3());
itemHolder.answer_ar1.setText(currentItem.getAnswer_ar1());
itemHolder.answer_ar2.setText(currentItem.getAnswer_ar2());
itemHolder.answer_ar3.setText(currentItem.getAnswer_ar3());
itemHolder.right_answer.setText(currentItem.getRight_answer());
itemHolder.question_en.setText(currentItem.getQuestion_en());
itemHolder.question_ar.setText(currentItem.getQuestion_ar());
itemHolder.desc_ar.setText(currentItem.getPrize_desc_ar());
itemHolder.desc_en.setText(currentItem.getPrize_desc_en());
String urlLogo = currentItem.getPrize_pic1();
loadImages(urlLogo, itemHolder);
setDefferinceTimer(itemHolder , currentItem.getEnd_date());
if (updateFuture == null) {
final Handler mainHandler = new Handler(Looper.getMainLooper());
updateFuture = Executors.newSingleThreadScheduledExecutor().scheduleAtFixedRate(new Runnable() {
@Override
public void run() {
setDefferinceTimer(itemHolder , currentItem.getEnd_date());
notifyDataSetChanged();
mainHandler.post(new Runnable() {
@Override
public void run() {
notifyDataSetChanged();
}
});
}
}, 0, 1000, TimeUnit.MILLISECONDS);
}
/* new Handler(Looper.getMainLooper()).post(new Runnable() {
@Override
public void run() {
new CountDownTimer(20000, 1000) {
public void onTick(long millisUntilFinished) {
startCountDown(itemHolder, currentItem.getEnd_date() + " 00:00:00");
notifyDataSetChanged();
}
public void onFinish() {
//counterTextView.setText("done!");
}
}.start();
}
});
*/
}
public void setDefferinceTimer(final RecyclerView.ViewHolder holder , String itemEndDate){
final ItemHolder itemHolder = (ItemHolder) holder;
current_date = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date());
// reachableDate = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(itemEndDate);
try {
d1 = format.parse(current_date);
d2 = format.parse(itemEndDate+" 00:00:00");
} catch (ParseException e) {
e.printStackTrace();
}
diff = d2.getTime() - d1.getTime();
diffSeconds = diff / 1000 % 60;
diffMinutes = diff / (60 * 1000) % 60;
diffHours = diff / (60 * 60 * 1000) % 24;
diffDays = diff / (24 * 60 * 60 * 1000);
itemHolder.days_tf.setText(""+diffDays);
itemHolder.hours_tf.setText(""+diffHours);
itemHolder.minutes_tf.setText(""+diffMinutes);
itemHolder.seconds_tf.setText(""+diffSeconds);
}
private void loadImages(String urlThumbnail, final RecyclerView.ViewHolder holder) {
final ItemHolder itemHolder = (ItemHolder) holder;
mImageLoader.get(urlThumbnail, new ImageLoader.ImageListener() {
@Override
public void onResponse(ImageLoader.ImageContainer response, boolean isImmediate) {
itemHolder.item_image.setImageBitmap(response.getBitmap());
//holder.salon_gender.setImageBitmap(response.getBitmap());
}
@Override
public void onErrorResponse(VolleyError error) {
}
});
}
@Override
public int getItemCount() {
return mListItems.size();
}
private class ItemHolder extends RecyclerView.ViewHolder {
public TextView item_id, item_description, end_date,
start_date, name_com_ar, name_com_en, question_ar,
question_en, answer_ar1, answer_ar2, answer_ar3, answer_en1,
answer_en2, answer_en3, right_answer , desc_ar , desc_en;
public TextView days_tf, hours_tf, minutes_tf, seconds_tf;
public CircleImageView item_image;
public ItemHolder(View itemView) {
super(itemView);
start_date = (TextView) itemView.findViewById(R.id.start_date);
end_date = (TextView) itemView.findViewById(R.id.end_date);
name_com_ar = (TextView) itemView.findViewById(R.id.name_com_ar);
name_com_en = (TextView) itemView.findViewById(R.id.name_com_en);
question_en = (TextView) itemView.findViewById(R.id.question_en);
question_ar = (TextView) itemView.findViewById(R.id.question_ar);
desc_ar = (TextView) itemView.findViewById(R.id.desc_ar);
desc_en = (TextView) itemView.findViewById(R.id.desc_en);
answer_ar1 = (TextView) itemView.findViewById(R.id.answer_ar1);
answer_ar2 = (TextView) itemView.findViewById(R.id.answer_ar2);
answer_ar3 = (TextView) itemView.findViewById(R.id.answer_ar3);
answer_en1 = (TextView) itemView.findViewById(R.id.answer_en1);
answer_en2 = (TextView) itemView.findViewById(R.id.answer_en2);
answer_en3 = (TextView) itemView.findViewById(R.id.answer_en3);
right_answer = (TextView) itemView.findViewById(R.id.right_answer);
item_id = (TextView) itemView.findViewById(R.id.item_id);
item_description = (TextView) itemView.findViewById(R.id.item_description);
item_image = (CircleImageView) itemView.findViewById(R.id.item_image);
days_tf = (TextView) itemView.findViewById(R.id.days_tf);
hours_tf = (TextView) itemView.findViewById(R.id.hours_tf);
minutes_tf = (TextView) itemView.findViewById(R.id.minutes_tf);
seconds_tf = (TextView) itemView.findViewById(R.id.seconds_tf);
}
}
解决方案
编辑
这里有一个示例，可用于更新RecyclerView中的可见项目.我假设您为RecyclerView的布局使用 LinearLayoutManager ./p>
首先，从您的代码中删除CountDownTimer.它的问题在于它使用主线程的循环程序来遍历消息(实际上，它使用当前线程"，但是由于您在主线程中对其进行了初始化，因此当前线程现在是主线程)而且只能安排一个有限的时间间隔.
现在是新的部分.假设有一个片段启动了RecyclerView及其所有相关部分.假设这些是您片段中可用的字段:
private AdapterItems myAdapter;
private LinearLayoutManager layoutManager;
private ScheduledFuture updateFuture;
然后，在完成所有视图，适配器和其他初始化之后，将以下部分放入您的onCreateView(...)中:
if (updateFuture == null) {
final Handler mainHandler = new Handler(Looper.getMainLooper());
updateFuture = Executors.newSingleThreadScheduledExecutor().scheduleAtFixedRate(new Runnable() {
@Override
public void run() {
final int firstVisible = layoutManager.findFirstVisibleItemPosition();
final int lastVisible = layoutManager.findLastVisibleItemPosition();
mainHandler.post(new Runnable() {
@Override
public void run() {
myAdapter.notifyItemRangeChanged(firstVisible, lastVisible - firstVisible + 1);
}
});
}
}, 0, 1000, TimeUnit.MILLISECONDS);
}
这里有一些代码说明.我们创建了一个新的单线程 ScheduledExecutorService，可用于以固定速率调度可运行对象(适配器上的android/support/v7/widget/RecyclerView.Adapter.html#notifyItemChanged％28int％29"rel =" nofollow> notifyItemChanged(position) .
I have count down timer as image below :
now these timers will start count down in each item, i tried many times to change this from my Adapter and it's not work,here is my code:
Edit :
public class AdapterItems extends RecyclerView.Adapter {
private ArrayList<TopCompetitions> mListItems = new ArrayList<>();
private ImageLoader mImageLoader;
private Context context;
private Handler handler;
/******************************************/
String current_date = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date());
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Date d1 = null;
Date d2 = null;
long diff;
long diffSeconds;
long diffMinutes;
long diffHours;
long diffDays;
String reachableDate = "";
/******************************************/
private ScheduledFuture updateFuture;
public AdapterItems(Context context) {
this.context = context;
mImageLoader = AppController.getInstance().getImageLoader();
}
public void setmListItems(ArrayList<TopCompetitions> mListItems) {
this.mListItems = mListItems;
//update the adapter to reflect the new set of mListItems
notifyDataSetChanged();
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.
from(parent.getContext()).
inflate(R.layout.custom_horizontal_row, parent, false);
return new ItemHolder(itemView);
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
final TopCompetitions currentItem = mListItems.get(position);
final ItemHolder itemHolder = (ItemHolder) holder;
/* start_date , name_com_ar , name_com_en,
question_en,answer_ar1,answer_ar2,answer_ar3
,answer_en1,answer_en2,answer_en3,right_answer;
*/
itemHolder.item_id.setText(currentItem.getPrize_id());
itemHolder.item_description.setText(currentItem.getName_com_ar());
itemHolder.start_date.setText(currentItem.getStart_date());
itemHolder.end_date.setText(currentItem.getEnd_date());
itemHolder.name_com_ar.setText(currentItem.getName_com_ar());
itemHolder.name_com_en.setText(currentItem.getName_com_en());
itemHolder.answer_en1.setText(currentItem.getAnswer_en1());
itemHolder.answer_en2.setText(currentItem.getAnswer_en2());
itemHolder.answer_en3.setText(currentItem.getAnswer_en3());
itemHolder.answer_ar1.setText(currentItem.getAnswer_ar1());
itemHolder.answer_ar2.setText(currentItem.getAnswer_ar2());
itemHolder.answer_ar3.setText(currentItem.getAnswer_ar3());
itemHolder.right_answer.setText(currentItem.getRight_answer());
itemHolder.question_en.setText(currentItem.getQuestion_en());
itemHolder.question_ar.setText(currentItem.getQuestion_ar());
itemHolder.desc_ar.setText(currentItem.getPrize_desc_ar());
itemHolder.desc_en.setText(currentItem.getPrize_desc_en());
String urlLogo = currentItem.getPrize_pic1();
loadImages(urlLogo, itemHolder);
setDefferinceTimer(itemHolder , currentItem.getEnd_date());
if (updateFuture == null) {
final Handler mainHandler = new Handler(Looper.getMainLooper());
updateFuture = Executors.newSingleThreadScheduledExecutor().scheduleAtFixedRate(new Runnable() {
@Override
public void run() {
setDefferinceTimer(itemHolder , currentItem.getEnd_date());
notifyDataSetChanged();
mainHandler.post(new Runnable() {
@Override
public void run() {
notifyDataSetChanged();
}
});
}
}, 0, 1000, TimeUnit.MILLISECONDS);
}
/* new Handler(Looper.getMainLooper()).post(new Runnable() {
@Override
public void run() {
new CountDownTimer(20000, 1000) {
public void onTick(long millisUntilFinished) {
startCountDown(itemHolder, currentItem.getEnd_date() + " 00:00:00");
notifyDataSetChanged();
}
public void onFinish() {
//counterTextView.setText("done!");
}
}.start();
}
});
*/
}
public void setDefferinceTimer(final RecyclerView.ViewHolder holder , String itemEndDate){
final ItemHolder itemHolder = (ItemHolder) holder;
current_date = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date());
// reachableDate = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(itemEndDate);
try {
d1 = format.parse(current_date);
d2 = format.parse(itemEndDate+" 00:00:00");
} catch (ParseException e) {
e.printStackTrace();
}
diff = d2.getTime() - d1.getTime();
diffSeconds = diff / 1000 % 60;
diffMinutes = diff / (60 * 1000) % 60;
diffHours = diff / (60 * 60 * 1000) % 24;
diffDays = diff / (24 * 60 * 60 * 1000);
itemHolder.days_tf.setText(""+diffDays);
itemHolder.hours_tf.setText(""+diffHours);
itemHolder.minutes_tf.setText(""+diffMinutes);
itemHolder.seconds_tf.setText(""+diffSeconds);
}
private void loadImages(String urlThumbnail, final RecyclerView.ViewHolder holder) {
final ItemHolder itemHolder = (ItemHolder) holder;
mImageLoader.get(urlThumbnail, new ImageLoader.ImageListener() {
@Override
public void onResponse(ImageLoader.ImageContainer response, boolean isImmediate) {
itemHolder.item_image.setImageBitmap(response.getBitmap());
//holder.salon_gender.setImageBitmap(response.getBitmap());
}
@Override
public void onErrorResponse(VolleyError error) {
}
});
}
@Override
public int getItemCount() {
return mListItems.size();
}
private class ItemHolder extends RecyclerView.ViewHolder {
public TextView item_id, item_description, end_date,
start_date, name_com_ar, name_com_en, question_ar,
question_en, answer_ar1, answer_ar2, answer_ar3, answer_en1,
answer_en2, answer_en3, right_answer , desc_ar , desc_en;
public TextView days_tf, hours_tf, minutes_tf, seconds_tf;
public CircleImageView item_image;
public ItemHolder(View itemView) {
super(itemView);
start_date = (TextView) itemView.findViewById(R.id.start_date);
end_date = (TextView) itemView.findViewById(R.id.end_date);
name_com_ar = (TextView) itemView.findViewById(R.id.name_com_ar);
name_com_en = (TextView) itemView.findViewById(R.id.name_com_en);
question_en = (TextView) itemView.findViewById(R.id.question_en);
question_ar = (TextView) itemView.findViewById(R.id.question_ar);
desc_ar = (TextView) itemView.findViewById(R.id.desc_ar);
desc_en = (TextView) itemView.findViewById(R.id.desc_en);
answer_ar1 = (TextView) itemView.findViewById(R.id.answer_ar1);
answer_ar2 = (TextView) itemView.findViewById(R.id.answer_ar2);
answer_ar3 = (TextView) itemView.findViewById(R.id.answer_ar3);
answer_en1 = (TextView) itemView.findViewById(R.id.answer_en1);
answer_en2 = (TextView) itemView.findViewById(R.id.answer_en2);
answer_en3 = (TextView) itemView.findViewById(R.id.answer_en3);
right_answer = (TextView) itemView.findViewById(R.id.right_answer);
item_id = (TextView) itemView.findViewById(R.id.item_id);
item_description = (TextView) itemView.findViewById(R.id.item_description);
item_image = (CircleImageView) itemView.findViewById(R.id.item_image);
days_tf = (TextView) itemView.findViewById(R.id.days_tf);
hours_tf = (TextView) itemView.findViewById(R.id.hours_tf);
minutes_tf = (TextView) itemView.findViewById(R.id.minutes_tf);
seconds_tf = (TextView) itemView.findViewById(R.id.seconds_tf);
}
}
解决方案
Edit
Here's a sample that can be used to update the visible items in your RecyclerView. I assume you use LinearLayoutManager for your RecyclerView's layout.
First of all, remove CountDownTimer from your code. The problem with it is that it uses the main thread's looper to loop through the messages (actually it uses the "current thread" but since you initialize it in your main thread, current thread is main thread now) and it can only be scheduled for a finite interval.
Now the new part. Assume there's your fragment that inits the RecyclerView and all its related parts. Let's say that these are the fields available in your fragment:
private AdapterItems myAdapter;
private LinearLayoutManager layoutManager;
private ScheduledFuture updateFuture;
Then put the following part into your onCreateView(...) after you're done with all the view, adapter and other initializations:
if (updateFuture == null) {
final Handler mainHandler = new Handler(Looper.getMainLooper());
updateFuture = Executors.newSingleThreadScheduledExecutor().scheduleAtFixedRate(new Runnable() {
@Override
public void run() {
final int firstVisible = layoutManager.findFirstVisibleItemPosition();
final int lastVisible = layoutManager.findLastVisibleItemPosition();
mainHandler.post(new Runnable() {
@Override
public void run() {
myAdapter.notifyItemRangeChanged(firstVisible, lastVisible - firstVisible + 1);
}
});
}
}, 0, 1000, TimeUnit.MILLISECONDS);
}
Here's a little explanation of the code. We create a new single threaded ScheduledExecutorService which can be used to schedule runnables at fixed rate (scheduleAtFixedRate(...)). Every 1000 milliseconds from the call of this method, there's going to be a new execution.
Now the inner part. Every layout manager (except the base class LayoutManager) has two very important methods: findFirstVisibleItemPosition() and findLastVisibleItemPosition(). As the names show, these can be used to find the first and last visible items' position in the adapter. Then we use these informations to call the RecyclerView's adapter's (myAdapter) notifyItemRangeChanged(...) which will update only the given items' view in the range by calling onBindViewHolder(...) automatically.
Note the mainHandler which is used to call the notifyItemRangeChanged(...) method on the UI thread as you cannot update the UI from a non-UI thread (and the one created by the ScheduledExecutorService is non-UI).
Don't forget to cancel your ScheduledFuture when you don't need the updates anymore by calling its cancel() method (e.g. in your fragment's onDestroyView()).
if (updateFuture != null) {
updateFuture.cancel(true);
updateFuture = null;
}
Original
You have your Items class which, I assume, contains all the data (images, text, etc.) for the list items. You should put the target date to this class as well, this way all your items can have different target dates. If you want to update this date later on, you'll have to change it in the appropriate Items instance and call notifyItemChanged(position) on your adapter.
这篇关于在RecyclerView中设置计数器的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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