NestedScrollview中的Recylerview（包含大量项目）会让Android崩溃

Question

我在NestedScrollView中有Recyclerview。现在我有20个项目要在Recylerview中填充，但它显示的UI在其主线程上工作太多，并且不断被崩溃或被要求等待消息。任何建议都会受到赞赏。

    UI:
    <?xml version="1.0" encoding="utf-8"?>

    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/view_main"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@drawable/bg">

        <android.support.v4.widget.NestedScrollView

            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:fillViewport="true">


                        <android.support.v7.widget.RecyclerView

                            android:id="@+id/recylerview"
                            android:layout_width="match_parent"
                            android:layout_height="wrap_content"
                            android:divider="@null"
                            android:orientation="horizontal" />

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



//List Item:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:id="@+id/view_main"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
>

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="4dp">


        <RelativeLayout
            android:id="@+id/rl_img"
            android:layout_width="@dimen/img_wextra"
            android:layout_height="wrap_content"
            android:background="@drawable/rl_bg"
            android:layout_alignBottom="@+id/ll_info"
            android:layout_alignTop="@+id/tv_title"
            android:orientation="horizontal">

            <ImageView
                android:id="@+id/img"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_centerHorizontal="true"
                android:layout_centerVertical="true"
                android:padding="4dp"
                android:maxHeight="30dp"
                android:maxWidth="30dp"
                android:scaleType="fitXY" />


            <ProgressBar
                android:id="@+id/pb_img"
                android:layout_width="@dimen/pb_size"
                android:layout_height="@dimen/pb_size"
                android:layout_centerHorizontal="true"
                android:layout_centerVertical="true"
                android:visibility="visible"

                />


        </RelativeLayout>

        <ImageView
            android:id="@+id/img_arrow"
            android:layout_width="@dimen/frwd_size"
            android:layout_height="@dimen/frwd_size"
            android:layout_alignParentEnd="true"
            android:layout_alignParentRight="true"
            android:layout_centerVertical="true"
            android:src="@drawable/icon_next" />


        <me.grantland.widget.AutofitTextView
            android:id="@+id/tv_title"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignLeft="@+id/ll_info"
            android:layout_toLeftOf="@+id/img_arrow"

            android:textColor="@color/item_heading"
            android:textSize="@dimen/text_size_medium" />


        <me.grantland.widget.AutofitTextView
            android:id="@+id/tv_name"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignLeft="@+id/ll_info"
            android:layout_below="@+id/tv_title"
            android:layout_toLeftOf="@+id/img_arrow"

            android:textSize="@dimen/text_size_small" />

        <me.grantland.widget.AutofitTextView
            android:id="@+id/tv_data"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignLeft="@+id/ll_info"
            android:layout_below="@+id/tv_name"
            android:layout_toLeftOf="@+id/img_arrow"

            android:textSize="@dimen/text_size_small" />


        <LinearLayout
            android:id="@+id/ll_info"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_above="@+id/ll_btns"
            android:layout_alignLeft="@+id/ll_btns"
            android:layout_below="@+id/tv_loc"
            android:layout_marginLeft="4dp"
            android:layout_marginTop="4dp"
            android:layout_toLeftOf="@+id/img_arrow"
            android:layout_toRightOf="@+id/rl_img"
            android:orientation="horizontal">

            <LinearLayout
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:orientation="vertical">

                <TextView
                    android:id="@+id/tv_title_1"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_weight="1.5"

                    android:textColor="@color/text_heading_color"
                    android:textSize="@dimen/text_size_small" />

                <TextView
                    android:id="@+id/tv_title_2"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_weight="1.5"

                    android:textColor="@color/text_heading_color"
                    android:textSize="@dimen/text_size_small" />




                <TextView
                    android:id="@+id/tv_title_3"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_weight="1.5"

                    android:textColor="@color/text_heading_color"
                    android:textSize="@dimen/text_size_small" />



                <TextView
                    android:id="@+id/tv_title_4"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_weight="1.5"

                    android:textColor="@color/text_heading_color"
                    android:textSize="@dimen/text_size_small" />

            </LinearLayout>


            <LinearLayout
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:orientation="vertical">



                <TextView
                    android:id="@+id/tv_userName"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_weight=".5"

                    android:maxLines="1"
                    android:text="0000000"
                    android:textColor="@color/colorBlack"
                    android:textSize="@dimen/text_size_small" />


                <TextView
                    android:id="@+id/tv_userdes"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_weight=".5"

                    android:maxLines="1"
                    android:text="0000000"
                    android:textColor="@color/colorBlack"
                    android:textSize="@dimen/text_size_small" />


                <TextView
                    android:id="@+id/tv_usernum"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_weight=".5"
                    android:maxLines="1"
                    android:text="0000000"
                    android:textColor="@color/colorBlack"
                    android:textSize="@dimen/text_size_small" />



                <TextView
                    android:id="@+id/tv_userrating"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_weight=".5"
                    android:maxLines="1"
                    android:text="0000000"
                    android:textColor="@color/colorBlack"
                    android:textSize="@dimen/text_size_small" />


            </LinearLayout>


        </LinearLayout>


    </RelativeLayout>
</RelativeLayout>


    Code:

         recylerview.setLayoutManager(new LinearLayoutManager(getContext(), LinearLayoutManager.VERTICAL, false));
            recylerview.setItemAnimator(new DefaultItemAnimator());
            recylerview.setNestedScrollingEnabled(false);
            recylerview.addItemDecoration(new SimpleDividerItemDecoration(getActivity()));
            ItemOffsetDecoration itemDecoration = new ItemOffsetDecoration(getActivity(), R.dimen.item_offset_mini);
            recylerview.addItemDecoration(itemDecoration);


    recylerview.setAdapter(itemAdapter);

//Adapter
public class ItemAdapter extends RecyclerView.Adapter<ItemAdapter.ItemViewHolder> {

    public interface OnItemClickListener {
        void onItemClick(ItemModel item);
    }

    private List<ItemModel> items;
    private Context context;
    private OnItemClickListener listener;


    public ItemAdapter(Context context, List<ItemModel> items, OnItemClickListener listener) {
        this.items = items;
        this.context = context;
        this.listener = listener;
    }

    @Override
    public ItemAdapter.ItemViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
        View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.item, viewGroup, false);
        return new ItemViewHolder(view);
    }

    @Override
    public void onBindViewHolder(ItemAdapter.ItemViewHolder viewHolder, int i) {

        viewHolder.bind(items.get(i), listener);


        viewHolder.tv_title.setText(items.get(i).getTitle());
        viewHolder.tv_name.setText(items.get(i).getItemTitle());
        viewHolder.tv_loc.setText(items.get(i).getItemLoc());
        viewHolder.tv_name.setTextColor(Color.BLACK);
        viewHolder.tv_loc.setTextColor(Color.BLACK);


        viewHolder.tv_userName.setText(items.get(i).getUserName());
        viewHolder.tv_userdes.setText(items.get(i).getUserDes());


        FragmentUtils.setBOLDFont(viewHolder.tv_title);
        FragmentUtils.setFont(viewHolder.tv_name);
        FragmentUtils.setFont(viewHolder.tv_loc);



        FragmentUtils.setFont(viewHolder.tv_title_1);
        FragmentUtils.setFont(viewHolder.tv_title_2);
        FragmentUtils.setFont(viewHolder.tv_title_3);
        FragmentUtils.setFont(viewHolder.tv_title_4);

        // Loading profile image
        if (items.get(i).getImage().size() != 0) {

            Drawable myIcon = context.getResources().getDrawable( R.drawable.not_found );
            ImageUtils.displayImageFromUrl(context, items.get(i).getImage().get(0).getThumbnail(), viewHolder.img,myIcon, new RequestListener<Drawable>() {
                @Override
                public boolean onLoadFailed(@android.support.annotation.Nullable GlideException e, Object model, Target<Drawable> target, boolean isFirstResource) {
                    viewHolder.pb_img.setVisibility(View.GONE);
                    return false;
                }

                @Override
                public boolean onResourceReady(Drawable resource, Object model, Target<Drawable> target, DataSource dataSource, boolean isFirstResource) {
                    viewHolder.pb_img.setVisibility(View.GONE);
                    return false;
                }
            });

        } else {
            ImageUtils.displayImageFromResources(context, viewHolder.img, R.drawable.not_found);
            viewHolder.pb_img.setVisibility(View.GONE);
        }

    }

    @Override
    public int getItemCount() {
        return items.size();
    }

    public class ItemViewHolder extends RecyclerView.ViewHolder {


        @BindView(R.id.tv_title)
        public TextView tv_title;

        @BindView(R.id.tv_name)
        public TextView tv_name;

        @BindView(R.id.tv_des)
        public TextView tv_des;

        @BindView(R.id.tv_userName)
        public TextView tv_userName;

        @BindView(R.id.tv_userLoc)
        public TextView tv_userLoc;



        @BindView(R.id.img)
        public ImageView img;

        @BindView(R.id.pb_img)
        public ProgressBar pb_img;


        @BindView(R.id.tv_title_1)
        public TextView tv_title_1;

        @BindView(R.id.tv_title_2)
        public TextView tv_title_2;

        @BindView(R.id.tv_title_3)
        public TextView tv_title_3;

        @BindView(R.id.tv_title_4)
        public TextView tv_title_4;


        public ItemViewHolder(View view) {
            super(view);
            ButterKnife.bind(this, view);
        }

        public void bind(final ItemModel item, final OnItemClickListener listener) {
            itemView.setOnClickListener(new View.OnClickListener() {

                @Override
                public void onClick(View v) {
                    listener.onItemClick(item);
                }

            });

        }
    }
}


///Log:

    01-23 10:14:19.343 11462-11467/com.app I/art: Do full code cache collection, code=252KB, data=241KB
    01-23 10:14:19.344 11462-11467/com.app I/art: Starting a blocking GC JitCodeCache
    01-23 10:14:19.344 11462-11467/com.app I/art: After code cache collection, code=213KB, data=181KB
    01-23 10:14:20.212 11462-11467/com.app I/art: Do partial code cache collection, code=250KB, data=207KB
    01-23 10:14:20.213 11462-11467/com.app I/art: After code cache collection, code=250KB, data=207KB
    01-23 10:14:20.213 11462-11467/com.app I/art: Increasing code cache capacity to 1024KB
    01-23 10:14:27.706 11462-11462/com.app I/Choreographer: Skipped 505 frames!  The application may be doing too much work on its main thread.
    01-23 10:14:35.519 11462-11462/com.app I/Choreographer: Skipped 464 frames!  The application may be doing too much work on its main thread.
    01-23 10:14:43.019 11462-11462/com.app I/Choreographer: Skipped 449 frames!  The application may be doing too much work on its main thread.
    01-23 10:14:50.488 11462-11462/com.app I/Choreographer: Skipped 447 frames!  The application may be doing too much work on its main thread.

Answer 1

这种情况正在发生，因为<RecyclerView>标记的wrap_content标记为<NestedScrollView>。这意味着您的1000个项目中的每一个都将为其创建一个视图持有者，从而导致数千个视图被充气和填充。我想即使你等待所有这一切发生，你的应用程序也会因OutOfMemoryError而崩溃。

显而易见的问题是，您希望在NestedScrollView中使用RecyclerView。如果你有这个：

<RelativeLayout
    ...>

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

</RelativeLayout>

RecyclerView实际上可以执行视图回收，您的应用应该会响应。

Answer 2

是的@Ben是正确的RecyclerView是VERTICAL而且wrap_content加上1000个项目在NestedScrollView

中使用它是没有意义的

尝试在RecyclerView或Relativelayout

中使用Linearlayout

另外，我可以看到你已经match_parent给了ImageView并再次以这种方式在父布局中给出了高度，每次调整大小都是UI中的额外负载

另请注意，maxWidth和maxHeight无法使用match_parent

<RelativeLayout
            android:id="@+id/rl_img"
            android:layout_width="@dimen/img_wextra"
            android:layout_height="wrap_content"
            android:background="@drawable/rl_bg"
            android:layout_alignBottom="@+id/ll_info"
            android:layout_alignTop="@+id/tv_title"
            android:orientation="horizontal">
        <ImageView
            android:id="@+id/img"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_centerHorizontal="true"
            android:layout_centerVertical="true"
            android:padding="4dp"
            android:maxHeight="30dp"
            android:maxWidth="30dp"
            android:scaleType="fitXY" />

对placeholder使用Progressbar而不是Imageview，还有一件事情更好。