在滚动过程中更改项

As the name implies, the views in a RecyclerView are recycled as you scroll down. This means that you need to keep the state of each item in your backing model, which in this case would be a Historyitem, and restore it in your onBindViewHolder.

1) Create position, max, and whatever other variables you need to save the state of the ProgressBar in your model.

2) Set the state of your ProgressBar based on the data in your backing model; on click, pass the position of the item to your FileDownload/StartMediaPlayer methods.

public void onBindViewHolder(final RecyclerView.ViewHolder viewHolder, int position) {
final Historyitem dataItem = stethitems.get(position);
final MyViewHolder myViewHolder = (MyViewHolder) viewHolder;
myViewHolder.progressplay.setMax(dataItem.getMax());
myViewHolder.progressplay.setProgress(dataItem.getPosition());
...
myViewHolder.stethstreamplay.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
FileDownload(dataItem.getmsg(), position);
}
});

3) Update the progress bar by updating the backing model and notifying that it was changed.

stethitems.get(position).setPosition(mPlayer.getCurrentPosition());
notifyItemChanged(position);

This is the expected behaviour of recyclerView. Since the view is recycled your items may get into random views. To overcome this you have to specify which item is put into which kind of view by yourself. This information can be kept in a SparseBooleanArray. what you can do is create a SparseBooleanArray in your adapter like this

SparseBooleanArray selectedItems = new SparseBooleanArray();

whenever your view changes, do:

selectedItems.put(viewItemIndex,true);

Now in your onBindViewHolder do

 if(selectedItems.get(position, false)){
//set progress bar of related to the view to desired position
}
else {
//do the default
}

This is the basic to solve your problem. You can adjust this logic to any kind of similar problem in recyclerView.

I had the same problem while handle a lot of data , it works with 5 because it renders the five elements that are visible on the screen but that gives prob with more elements. The thing is ..

Sometimes RecyclerView and listView just skips Populating Data. In case of RecyclerView binding function is skipped while scrolling but when you try and debug the recyclerView adapter it will work fine as it will call onBind every time , you can also see the official google developer's view The World of listView. Around 20 min -30 min they will explain that you can never assume the getView by position will be called every time.

so, I will suggest to use

RecyclerView DataBinder created by satorufujiwara.

or

RecyclerView MultipleViewTypes Binder created by yqritc.

These are other Binders available if you find those easy to work around .

This is the way to deal with MultipleView Types or if you are using large amount of data . These binders can help you just read the documentation carefully that will fix it, peace!!

This line changes progress to 0 on each bind

myViewHolder.progressplay.setProgress(0);

Save its state somewhere then load it in this same line.

Why don't you try like this,

    HashMap<String, Integer> progressHashMap = new HashMap<>();


//...
if(!progressHashMap.containsKey(downloadpath)){
progressHashMap.put(downloadpath, mPlayer.getCurrentPosition());
}


progressbar.setProgress(progressHashMap.get(downloadpath));

try this

@Override public void smoothScrollToPosition(RecyclerView    recyclerView, RecyclerView.State state,
int position) {    LinearSmoothScroller linearSmoothScroller =
new LinearSmoothScroller(recyclerView.getContext()) {
@Override
public PointF computeScrollVectorForPosition(int targetPosition) {
return LinearLayoutManager.this
.computeScrollVectorForPosition(targetPosition);
}
};    linearSmoothScroller.setTargetPosition(position);    startSmoothScroll(linearSmoothScroller); }

see this also

Please try this

1. If you are using ListView - override the following methods.

    @Override
   public int getViewTypeCount() {
   return getCount();
   }
   
   
   @Override
   public int getItemViewType(int position) {
   return position;
   }
   

2. If you are using RecyclerView - override only getItemViewType() method.

    @Override
   public int getItemViewType(int position) {
   return position;
   }
   

Add setHasStableIds(true); in your adapter constructor and Override these two methods in adapter. It also worked if anyone using a RecyclerView inside a ViewPager which is also inside a NestedScrollView.

@Override
public long getItemId(int position) {
return position;
}


@Override
public int getItemViewType(int position) {
return position;
}

Just put you recylerView in a NestedScroll View in your xml and add the property nestedScrollingEnabled = false.

And on your adapter onBindViewHolder add this line

final MyViewHolder viewHolder = (MyViewHolder)holder;

Use this viewHolder object with your views to setText or do any kind of Click events.

e.g viewHolder.txtSubject.setText("Example");

I had the similar issue and searched alot for the right answer. Basically it is more of a design of recycler view that it updates the view on the scroll because it refreshes the view.

So all you need to do is at the bind time tell it not to refresh it.

This is how your onBindViewHolder should look like

@Override
@SuppressWarnings("unchecked")
public void onBindViewHolder(final BaseViewHolder holder, final int position) {
holder.bind(mList.get(position));


// This is the mighty fix of the issue i was having
// where recycler view was updating the items on scroll.
holder.setIsRecyclable(false);
}

I have faced the same problem while I was trying to implement a recyclerview that contains a edittex and a checkbox as a row elements. I solved the scrolling value changing problem just by adding the following two lines in the adapter class.

@Override
public long getItemId(int position) {
return position;
}


@Override
public int getItemViewType(int position) {
return position;
}

I hope it will be a possible solution. Thanks

recyclerview.setItemViewCacheSize(YourList.size());

When we are changing RecyclerView items dynamically (i.e. when changing background color of a specific RecyclerView item), it could change appearance of the items in unexpected ways when scrolling due to the nature of how RecyclerView reuse its items.

However to avoid that it is possible to use android.support.v4.widget.NestedScrollView wrapped around the RecyclerView and letting the NestedScrollView handle the scrolling.

<android.support.v4.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="match_parent">


<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent">


<android.support.v7.widget.RecyclerView
android:id="@+id/recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent"/>


</LinearLayout>
</android.support.v4.widget.NestedScrollView>

And then in the code you can disable nested scrolling for the RecyclerView to smooth out scrolling by letting only the NestedScrollView to handle scrolling.

ViewCompat.setNestedScrollingEnabled(recyclerView, false);

Override the method getItemViewType in adapter. in kotlin use

override fun getItemViewType(position: Int): Int {
return position
}

If your recyclerview ViewHolder has more logic or has a different different view then you should try:

 **order_recyclerView.setItemViewCacheSize(x);**

where x is the size of the list. The above works for me, I hope it works for you too.