Question

一般任务：我想实施“拖拽和放大将“和”滑动到“解雇”功能下放到FirebaseRecyclerAdapter。它应该是这样的： Drag and swipe .gif expample. 首先，我将创建一个允许传递事件回调的接口：

public interface ItemTouchHelperAdapter {
boolean onItemMove(int fromPosition, int toPosition);
void onItemDismiss(int position);  }

创建ItemTouchHelperCallback，该界面允许侦听“移动”和“滑动”事件：

public class ItemTouchHelperCallback extends ItemTouchHelper.Callback  {
private final ItemTouchHelperAdapter mAdapter;
public ItemTouchHelperCallback(ItemTouchHelperAdapter adapter) {
    mAdapter = adapter;
}

@Override
public boolean isLongPressDragEnabled() {
    return true;
}

@Override
public boolean isItemViewSwipeEnabled() {
    return true;
}
@Override
public int getMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
    int dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN;
    int swipeFlags = ItemTouchHelper.START | ItemTouchHelper.END;
    return makeMovementFlags(dragFlags, swipeFlags);
}

@Override
public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
    mAdapter.onItemMove(viewHolder.getAdapterPosition(),target.getAdapterPosition());
    return true;
}

@Override
public void onSwiped(RecyclerView.ViewHolder viewHolder, int direction) {
    mAdapter.onItemDismiss(viewHolder.getAdapterPosition());
}}

最后创建FirebaseRecyclerAdapter，它实现了之前创建的ItemTouchHelperAdapter：

public class PurchaseListAdapter extends FirebaseRecyclerAdapter<Purchase, PurchaseListHolder> implements ItemTouchHelperAdapter {
public PurchaseListAdapter(Class<Purchase> modelClass, int modelLayout, Class<PurchaseListHolder> viewHolderClass, Query ref) {
    super(modelClass, modelLayout, viewHolderClass, ref);
}

@Override
protected void populateViewHolder(PurchaseListHolder viewHolder, final Purchase model, final int position) {
    viewHolder.mName.setText(model.getName());
}

@Override
protected void onChildChanged(ChangeEventListener.EventType type, int index, int oldIndex) {
    super.onChildChanged(type, index, oldIndex);
}

@Override
public boolean onItemMove(int fromPosition, int toPosition) {
   // TODO: Add functionality for swapping items in FirebaseDatabase
    return true;
}

@Override
public void onItemDismiss(int position) {
    getRef(position).removeValue();
}}

“swipe-to-dismiss”（onItemDismiss）的功能非常好用。但我无法弄清楚如何实现onItemMove函数。理想情况下，它应该在Firebase数据库中滑动项目，但我找不到办法。

也许有人知道任何其他方式实现RecyclerView“刷卡到解雇”和“药物和丢弃”功能，这将与Firebase一起使用？

如何使用FirebaseRecyclerAdapter交换Firebase数据库中的项目？

0 个答案: