我的项目有不同的布局,有时我通过在布局中拖动项目在RecyclerView之上创建一个差距或间隙.当我回滚到RecyclerView的顶部时,一些项目被重新排序,并且它们的空白被填充.
行为被捕获在这里：
行为被捕获在这里：
填补空白是可以的.拖动时项目更改位置也可以.问题在于滚动到顶部.滚动结束时会重新排序 – 我没有触摸屏幕.
这是我如何创建回收记录和布局管理器
recyclerView = (RecyclerView)layout.findViewById(R.id.recycler_view);
stagaggeredGridLayoutManager =
new StaggeredGridLayoutManager(
getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE ? 3 : 2,StaggeredGridLayoutManager.VERTICAL);
recyclerView.setLayoutManager(stagaggeredGridLayoutManager);
stagaggeredList = getListItemData();
StatisticsGridViewAdapter rcAdapter = new StatisticsGridViewAdapter(this.getActivity(),stagaggeredList,recyclerView);
ItemTouchHelper.Callback callback = new StatisticsTouchHelperCallback(rcAdapter);
touchHelper = new ItemTouchHelper(callback);
touchHelper.attachToRecyclerView(recyclerView);
recyclerView.setAdapter(rcAdapter);
ItemTouchHelper类
public class StatisticsTouchHelperCallback extends ItemTouchHelper.Callback {
private final ItemTouchHelperAdapter touchHelperAdapter;
@Override
public boolean isLongPressDragEnabled() {
return true;
}
@Override
public boolean isItemViewSwipeEnabled() {
return false;
}
@Override
public int getMovementFlags(RecyclerView recyclerView,RecyclerView.ViewHolder viewHolder) {
int dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN |
ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT;
int swipeFlags = ItemTouchHelper.START | ItemTouchHelper.END;
return makeMovementFlags(dragFlags,swipeFlags);
}
@Override
public boolean onMove(RecyclerView recyclerView,RecyclerView.ViewHolder viewHolder,RecyclerView.ViewHolder target) {
touchHelperAdapter.onItemMove(viewHolder.getAdapterPosition(),target.getAdapterPosition());
return false;
}
@Override
public void onSwiped(RecyclerView.ViewHolder viewHolder,int direction) {
touchHelperAdapter.onItemDismiss(viewHolder.getAdapterPosition());
}
public StatisticsTouchHelperCallback(ItemTouchHelperAdapter adapter) {
touchHelperAdapter = adapter;
}
}
RecyclerView适配器
public class StatisticsGridViewAdapter extends RecyclerView.Adapter<StatisticsGridItemViewHolder> implements ItemTouchHelperAdapter {
private List<Statistic> itemList;
private Context context;
@Override
public StatisticsGridItemViewHolder onCreateViewHolder(ViewGroup parent,int viewType) {
View layoutView = LayoutInflater.from(parent.getContext()).inflate(itemList.get(viewType).getStatisticType().getStringResourcesId(),null);
StatisticsGridItemViewHolder rcv = new StatisticsGridItemViewHolder(layoutView,viewType);
return rcv;
}
@Override
public void onBindViewHolder(final StatisticsGridItemViewHolder holder,int position) {
holder.getMenu().setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
PopupMenu popup = new PopupMenu(v.getContext(),holder.getMenu());
popup.getMenuInflater().inflate(R.menu.statistics__widget__popup_menu,popup.getMenu());
Menu menu = popup.getMenu();
MenuItem item = menu.add(R.string.statistics__widget__menu_item__pin_to_dashboard);
//item.setOnMenuItemClickListener()
popup.show();
}
});
}
@Override
public int getItemCount() {
return this.itemList.size();
}
@Override
public boolean onItemMove(int fromPosition,int toPosition) {
if (fromPosition < toPosition) {
for (int i = fromPosition; i < toPosition; i++) {
Collections.swap(itemList,i,i + 1);
}
} else {
for (int i = fromPosition; i > toPosition; i--) {
Collections.swap(itemList,i - 1);
}
}
notifyItemMoved(fromPosition,toPosition);
return true;
}
@Override
public void onItemDismiss(int position) {
itemList.remove(position);
notifyItemRemoved(position);
}
@Override
public int getItemViewType(int position) {return itemList.get(position).getStatisticType().getPosition();
}
public StatisticsGridViewAdapter(Context context,List<Statistic> itemList) {
this.itemList = itemList;
this.context = context;
}
}
interface ItemTouchHelperAdapter {
boolean onItemMove(int fromPosition,int toPosition);
void onItemDismiss(int position);
}
现在我使用12种不同的布局,结构相同.只有高度不同才能模拟最终的小部件.
项目布局示例
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<LinearLayout
android:id="@+id/statistics__widget__main_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@drawable/order_tile_final"
android:layout_marginLeft="5dp"
android:layout_marginRight="5dp"
android:layout_marginTop="2dp"
android:layout_marginBottom="7dp"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="17dp"
android:orientation="horizontal">
<TextView
android:id="@+id/widget_title"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="@string/statistics__widget__forms_filled_title"
style="@style/tablet_common_font__main_3"
android:paddingTop="10dp"
android:layout_weight="1"/>
<ImageView
android:id="@+id/widget_menu"
android:layout_width="wrap_content"
android:layout_height="23dp"
android:layout_marginTop="7dp"
android:paddingTop="5dp"
android:layout_marginRight="8dp"
android:src="@drawable/a_menu_dark"/>
</LinearLayout>
<TextView
android:id="@+id/widget_value"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
style="@style/tablet_common_font__headline_2"
android:layout_marginLeft="17dp"
android:layout_marginBottom="6dp"/>
</LinearLayout>
</LinearLayout>
解决方法
我认为这是
StaggeredGridLayoutManager的常见行为：
When scroll state is changed to SCROLL_STATE_IDLE,StaggeredGrid will check if there are gaps in the because of full span items. If it finds,it will re-layout and move items to correct positions with animations.
您可以通过将战略改为GAP_HANDLING_NONE来阻止填补差距的行为：
stagaggeredGridLayoutManager.setGapStrategy(
StaggeredGridLayoutManager.GAP_HANDLING_NONE);
