RecyclerView does not Recycling Views when use it

2019-03-08 23:07发布

问题:

I'm using RecyclerView inside NestedScrollView. Also i set setNestedScrollingEnabled to false for recyclerview

to support lower API

ViewCompat.setNestedScrollingEnabled(mRecyclerView, false);

Now! When user scrolled the view every thing seems okay, but!!! views in recyclerview does not recycled!!! and Heap size grows swiftly!!

Update: RecyclerView layout manager is StaggeredLayoutManager

fragment_profile.xml:

<android.support.design.widget.CoordinatorLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/coordinator"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

        <android.support.design.widget.AppBarLayout
            android:id="@+id/appbar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar" >
        </android.support.design.widget.AppBarLayout>

        <android.support.v4.widget.SwipeRefreshLayout
            android:id="@+id/profileSwipeRefreshLayout"
            android:layout_width="match_parent"
            android:layout_height="match_parent" >

                <!-- RecyclerView and NestedScrollView -->
                <include layout="@layout/fragment_profile_details" />

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

</android.support.design.widget.CoordinatorLayout>

fragment_profile_details.xml:

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/rootLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    android:orientation="vertical" >

        <android.support.v4.widget.NestedScrollView
            android:id="@+id/nested_scrollbar"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_gravity="fill_vertical"
            app:layout_behavior="@string/appbar_scrolling_view_behavior"
            android:fillViewport="true"
            android:scrollbars="none" >

                <LinearLayout
                    android:id="@+id/nested_scrollbar_linear"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:descendantFocusability="blocksDescendants"
                    android:orientation="vertical" >

                        <android.support.v7.widget.CardView
                            android:id="@+id/profileCardview"
                            android:layout_width="match_parent"
                            android:layout_height="wrap_content"
                            app:cardBackgroundColor="@color/card_backgroind"
                            app:cardCornerRadius="0dp"
                            app:cardElevation="0dp" >

                            <!-- Profile related stuff like avatar and etc. --->

                        </android.support.v7.widget.CardView>

                        <android.support.v7.widget.RecyclerView
                            android:id="@+id/list_view"
                            android:layout_width="match_parent"
                            android:layout_height="wrap_content"
                            android:layout_marginBottom="@dimen/four"
                            android:layout_marginEnd="@dimen/four"
                            android:layout_marginLeft="@dimen/four"
                            android:layout_marginRight="@dimen/four"
                            android:layout_marginStart="@dimen/four"
                            android:layout_marginTop="@dimen/four"
                            app:layout_behavior="@string/appbar_scrolling_view_behavior"
                            android:clipToPadding="false" />

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

ProfileFragment.java:

mAdapter        = new MainAdapter(getActivity(), glide, Data);

listView        = (RecyclerView) view.findViewById(R.id.list_view);

ViewCompat.setNestedScrollingEnabled(listView, false);  
listView.setAdapter(mAdapter);

mStaggeredLM    = new StaggeredGridLayoutManager(2, StaggeredGridLayoutManager.VERTICAL);
mStaggeredLM.setGapStrategy(StaggeredGridLayoutManager.GAP_HANDLING_MOVE_ITEMS_BETWEEN_SPANS);

listView.setLayoutManager(mStaggeredLM);

mScroll.setOnScrollChangeListener(new OnScrollChangeListener() {

        @Override
        public void onScrollChange(NestedScrollView arg0, int arg1, int arg2, int arg3, int arg4) {

            View view   = (View) mScroll.getChildAt(mScroll.getChildCount() - 1);
            int diff    = (view.getBottom() - ( mScroll.getHeight() + mScroll.getScrollY()));

            if(diff == 0){

                int visibleItemCount            = mStaggeredLM.getChildCount();
                int totalItemCount              = mStaggeredLM.getItemCount();

                int[] lastVisibleItemPositions  = mStaggeredLM.findLastVisibleItemPositions(null);
                int lastVisibleItemPos  = getLastVisibleItem(lastVisibleItemPositions);

                Log.e("getChildCount", String.valueOf(visibleItemCount));
                Log.e("getItemCount", String.valueOf(totalItemCount));
                Log.e("lastVisibleItemPos", String.valueOf(lastVisibleItemPos));

                if ((visibleItemCount + 5) >= totalItemCount) {

                    mLoadMore.setVisibility(View.VISIBLE);
                    Log.e("LOG", "Last Item Reached!");
                }

                mMore = true;
                mFresh = false;
                mRefresh = false;
                getPosts();
            }

        }

    });

P.s : I've set load more to scroll view, because recyclerview do it continuously and none stoppable!

Any help is appreciated

回答1:

This is because we have a recycler view which has scroll behaviour inside a scroll view. (scroll inside a scroll)

I think the best way to resolve this issue is to your profileCardview as a header in your recycler view and then remove the nested scroll view.

If it were a listview then it was as simple as listView.addHeaderView(profileCardView) but for the Recycler view there is no addheadview equivalent. Hence you could refer the below link to change your implementation.

Is there an addHeaderView equivalent for RecyclerView?



回答2:

For a RecyclerView or ListView the height should be constant, because if it will not a constant size then how it will manage the maximum number of visible rows in memory. Try by changing RecyclerView attribute android:layout_height="match_parent" instead of "wrap_content". It should improve your memory management.