RecyclerView calling onCreateViewHolder and onBindViewHolder for all items at once

I have a recyclerView capable of showing the maximum of 3 items on screen, but it calls onCreateViewHolder and onBindViewHolder for all 45 items in the list, all at once (as in the LOG below).

Shouldn't it be calling those methods only as I scroll those items to the screen?

*I am using a list with 0's and 1's as a test to define which layout it should use.

My Adapter Code

public class MyRecyclerAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

int[] post_list;
private static final int TYPE_0 =0;
private static final int TYPE_1=1;
private LayoutInflater inflater;
private Context context;
Activity mActivity;

public MyRecyclerAdapter(Context context, int[] list, Activity mActivity){
    this.context=context;
    inflater=LayoutInflater.from(context);
    this.list=list;
    this.mActivity = mActivity;
}

@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    Log.e("onCreateViewHolder", "CALLED");
    if(viewType== TYPE_0){
        View view=inflater.inflate(R.layout.layout_type0, parent,false);
        Type0Holder holder=new Type0Holder(view);
        return holder;
    }
    else{
        View view=inflater.inflate(R.layout.layout_type1, parent,false);
        Type1Holder holder=new Type1Holder (view);
        return holder;
    }


}

@Override
public int getItemViewType(int position) {
    if(list[position]==0) {
        return TYPE_0;
    }
    else {
        return TYPE_1;
    }
}

@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
    if(holder instanceof Type0Holder){
        Type0Holder type0Holder = (Type0Holder) holder;
        type0Holder .mTextView.setText("Layout type 0");
        Glide.with(mActivity.getApplicationContext()).load(R.drawable.imageTest).into(type0Holder.mImageView);
    }
    else{
        Type1Holder type1Holder = (Type1Holder ) holder;
        type1Holder .mTextView.setText("Layout type 1");
        Glide.with(mActivity.getApplicationContext()).load(R.drawable.imageTest).into(type1Holder.mImageView);
    }
    Log.e("onBindViewHolder", String.valueOf(position));

}

@Override
public int getItemCount() {
    return post_list.length;
}

class Type0Holder extends RecyclerView.ViewHolder {
    TextView mTextView;
    ImageView mImageView;

    public Type0Holder (View view) {
        super(view);
        mTextView= (TextView) itemView.findViewById(R.id.text_view0);
        mImageView= (ImageView) itemView.findViewById(R.id.image_view0);

    }
}

class Type1Holder extends RecyclerView.ViewHolder {
    TextView mTextView;
    ImageView mImageView;

    public ImagePostHolder(View itemView) {
        super(itemView);
        mTextView= (TextView) itemView.findViewById(R.id.text_view1);
        mImageView= (ImageView) itemView.findViewById(R.id.image_view1);
    }
}

My Recycler xml

  <android.support.v4.widget.NestedScrollView
    android:id="@+id/nested_scroll_view"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    android:fillViewport="true"
    android:paddingBottom="3dp"
    >


    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"
        android:orientation="vertical"
        android:clipToPadding="false">


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


    </RelativeLayout>



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

My LOG showing it is calling all items at once, even the ones that are not visible.

10-23 15:15:46.093 28766-28766/com.example..E/CREATE HOLDER: CALLED
10-23 15:15:46.113 28766-28766/com.example..E/HOLDER: 0
10-23 15:15:46.113 28766-28766/com.example..E/CREATE HOLDER: CALLED
10-23 15:15:46.113 28766-28766/com.example..E/HOLDER: 1
10-23 15:15:46.113 28766-28766/com.example.. E/CREATE HOLDER: CALLED
10-23 15:15:46.123 28766-28766/com.example..E/HOLDER: 2
10-23 15:15:46.123 28766-28766/com.example..E/CREATE HOLDER: CALLED
10-23 15:15:46.123 28766-28766/com.example..E/HOLDER: 3
10-23 15:15:46.123 28766-28766/com.example..E/CREATE HOLDER: CALLED
10-23 15:15:46.133 28766-28766/com.example..E/HOLDER: 4
10-23 15:15:46.133 28766-28766/com.example..E/CREATE HOLDER: CALLED
10-23 15:15:46.133 28766-28766/com.example..E/HOLDER: 5
10-23 15:15:46.143 28766-28766/com.example..E/CREATE HOLDER: CALLED
10-23 15:15:46.143 28766-28766/com.example..E/HOLDER: 6
10-23 15:15:46.143 28766-28766/com.example..E/CREATE HOLDER: CALLED
10-23 15:15:46.143 28766-28766/com.example..E/HOLDER: 7
10-23 15:15:46.153 28766-28766/com.example..E/CREATE HOLDER: CALLED
10-23 15:15:46.153 28766-28766/com.example..E/HOLDER: 8
10-23 15:15:46.153 28766-28766/com.example..E/CREATE HOLDER: CALLED
10-23 15:15:46.153 28766-28766/com.example..E/HOLDER: 9
10-23 15:15:46.163 28766-28766/com.example..E/CREATE HOLDER: CALLED
10-23 15:15:46.163 28766-28766/com.example..E/HOLDER: 10
10-23 15:15:46.163 28766-28766/com.example..E/CREATE HOLDER: CALLED
10-23 15:15:46.163 28766-28766/com.example..E/HOLDER: 11
10-23 15:15:46.173 28766-28766/com.example..E/CREATE HOLDER: CALLED
10-23 15:15:46.173 28766-28766/com.example..E/HOLDER: 12
10-23 15:15:46.173 28766-28766/com.example..E/CREATE HOLDER: CALLED
10-23 15:15:46.183 28766-28766/com.example..E/HOLDER: 13
10-23 15:15:46.183 28766-28766/com.example..E/CREATE HOLDER: CALLED
10-23 15:15:46.183 28766-28766/com.example..E/HOLDER: 14
10-23 15:15:46.183 28766-28766/com.example..E/CREATE HOLDER: CALLED
10-23 15:15:46.183 28766-28766/com.example..E/HOLDER: 15
10-23 15:15:46.193 28766-28766/com.example..E/CREATE HOLDER: CALLED
10-23 15:15:46.193 28766-28766/com.example..E/HOLDER: 16
10-23 15:15:46.193 28766-28766/com.example..E/CREATE HOLDER: CALLED
10-23 15:15:46.193 28766-28766/com.example..E/HOLDER: 17
    10-23 15:15:46.203 28766-28766/com.example..E/CREATE HOLDER: CALLED
10-23 15:15:46.203 28766-28766/com.example..E/HOLDER: 18
10-23 15:15:46.203 28766-28766/com.example..E/CREATE HOLDER: CALLED
10-23 15:15:46.213 28766-28766/com.example.. E/HOLDER: 19
    10-23 15:15:46.213 28766-28766/com.example.. E/CREATE HOLDER: CALLED
    10-23 15:15:46.213 28766-28766/com.example.. E/HOLDER: 20
    10-23 15:15:46.213 28766-28766/com.example.. E/CREATE HOLDER: CALLED
    10-23 15:15:46.213 28766-28766/com.example.. E/HOLDER: 21
10-23 15:15:46.223 28766-28766/com.example.. E/CREATE HOLDER: CALLED
10-23 15:15:46.223 28766-28766/com.example.. E/HOLDER: 22
10-23 15:15:46.223 28766-28766/com.example.. E/CREATE HOLDER: CALLED
10-23 15:15:46.233 28766-28766/com.example.. E/HOLDER: 23
10-23 15:15:46.233 28766-28766/com.example.. E/CREATE HOLDER: CALLED
10-23 15:15:46.233 28766-28766/com.example.. E/HOLDER: 24
10-23 15:15:46.233 28766-28766/com.example.. E/CREATE HOLDER: CALLED
10-23 15:15:46.233 28766-28766/com.example.. E/HOLDER: 25
10-23 15:15:46.243 28766-28766/com.example.. E/CREATE HOLDER: CALLED
10-23 15:15:46.243 28766-28766/com.example.. E/HOLDER: 26
10-23 15:15:46.243 28766-28766/com.example.. E/CREATE HOLDER: CALLED
10-23 15:15:46.243 28766-28766/com.example.. E/HOLDER: 27
10-23 15:15:46.253 28766-28766/com.example.. E/CREATE HOLDER: CALLED
10-23 15:15:46.253 28766-28766/com.example.. E/HOLDER: 28
10-23 15:15:46.253 28766-28766/com.example.. E/CREATE HOLDER: CALLED
10-23 15:15:46.253 28766-28766/com.example.. E/HOLDER: 29
10-23 15:15:46.263 28766-28766/com.example.. E/CREATE HOLDER: CALLED
10-23 15:15:46.263 28766-28766/com.example.. E/HOLDER: 30
10-23 15:15:46.263 28766-28766/com.example.. E/CREATE HOLDER: CALLED
10-23 15:15:46.263 28766-28766/com.example.. E/HOLDER: 31
10-23 15:15:46.273 28766-28766/com.example.. E/CREATE HOLDER: CALLED
10-23 15:15:46.283 28766-28766/com.example.. E/HOLDER: 32
10-23 15:15:46.283 28766-28766/com.example.. E/CREATE HOLDER: CALLED
10-23 15:15:46.283 28766-28766/com.example.. E/HOLDER: 33
10-23 15:15:46.293 28766-28766/com.example.. E/CREATE HOLDER: CALLED
10-23 15:15:46.313 28766-28766/com.example.. E/HOLDER: 34
10-23 15:15:46.313 28766-28766/com.example.. E/CREATE HOLDER: CALLED
10-23 15:15:46.323 28766-28766/com.example.. E/HOLDER: 35
10-23 15:15:46.323 28766-28766/com.example.. E/CREATE HOLDER: CALLED
10-23 15:15:46.323 28766-28766/com.example.. E/HOLDER: 36
10-23 15:15:46.333 28766-28766/com.example.. E/CREATE HOLDER: CALLED
10-23 15:15:46.333 28766-28766/com.example.. E/HOLDER: 37
10-23 15:15:46.333 28766-28766/com.example.. E/CREATE HOLDER: CALLED
10-23 15:15:46.343 28766-28766/com.example.. E/HOLDER: 38
10-23 15:15:46.343 28766-28766/com.example.. E/CREATE HOLDER: CALLED
10-23 15:15:46.343 28766-28766/com.example.. E/HOLDER: 39
10-23 15:15:46.343 28766-28766/com.example.. E/CREATE HOLDER: CALLED
10-23 15:15:46.353 28766-28766/com.example.. E/HOLDER: 40
10-23 15:15:46.353 28766-28766/com.example.. E/CREATE HOLDER: CALLED
10-23 15:15:46.353 28766-28766/com.example.. E/HOLDER: 41
10-23 15:15:46.353 28766-28766/com.example.. E/CREATE HOLDER: CALLED
10-23 15:15:46.363 28766-28766/com.example.. E/HOLDER: 42
10-23 15:15:46.363 28766-28766/com.example.. E/CREATE HOLDER: CALLED
10-23 15:15:46.363 28766-28766/com.example.. E/HOLDER: 43
10-23 15:15:46.373 28766-28766/com.example.. E/CREATE HOLDER: CALLED
10-23 15:15:46.373 28766-28766/com.example.. E/HOLDER: 44
10-23 15:15:46.373 28766-28766/com.example.. E/CREATE HOLDER: CALLED
10-23 15:15:46.383 28766-28766/com.example.. E/HOLDER: 45

UPDATE 1 - I found out that the reason my recyclerView is not recycling is because it is inside a NestedScrowView, so how do I make it recycle the view even if its inside the NestedScrowView?

I had the same problem. In my case NestedScrollView is the root for Bottom Sheet and I replaced it with a FrameLayout, and it worked.

If you can, you should try using a FrameLayout

Disable nestedScrolling on RecyclerView:

mRecyclerView.setNestedScrollingEnabled(false);

来源：https://stackoverflow.com/questions/40206040/recyclerview-calling-oncreateviewholder-and-onbindviewholder-for-all-items-at-on

标签

android

performance

android-recyclerview

nestedscrollview