今天我们就来实现RecyclerView的侧滑删除和长按拖拽功能,实现这两个功能我们只需要一个类—— ItemTouchHelper
Google官方文档上是这么介绍的:
This is a utility class to add swipe to dismiss and drag & drop support to RecyclerView.意思就是:这是一个支持RecyclerView滑动删除和拖拽的实用工具类
接下来接着上一节“RecyclerView实现Listview-1”实现侧滑删除和长按拖拽
1、在ThirdTabFragment中定义
private ItemTouchHelper mItemTouchHeler;
2、在OnCreateView中的 recyclerView.setAdapter(adapter)下面接着写代码
ItemTouchHelper.Callback callback = new ItemTouchHelper.SimpleCallback(ItemTouchHelper.UP | ItemTouchHelper.DOWN, ItemTouchHelper.RIGHT) {
@Override
public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
int fromPosition = viewHolder.getAdapterPosition();//得到拖动ViewHolder的position
int toPosition = target.getAdapterPosition();//得到目标ViewHolder的position
if (fromPosition < toPosition) {
//分别把中间所有的item的位置重新交换
for (int i = fromPosition; i < toPosition; i++) {
Collections.swap(data, i, i + 1);
}
} else {
for (int i = fromPosition; i > toPosition; i--) {
Collections.swap(data, i, i - 1);
}
}
adapter.notifyItemMoved(fromPosition, toPosition);
return true;
}
@Override
public void onSwiped(RecyclerView.ViewHolder viewHolder, int direction) {
int position = viewHolder.getAdapterPosition();
data.remove(position);
adapter.notifyItemRemoved(position);
}
};
mItemTouchHeler = new ItemTouchHelper(callback);
mItemTouchHeler.attachToRecyclerView(recyclerView);
但是这里面的数据data变为下面List,不在是String[]类型
List<String> data = new ArrayList<String>();
for (int i = 0; i < 100; ++i) {
data.add(new String("item") + i);
}
3、MyAdapter中数据也改为如下:
public List<String> mDataset;
public MyAdapter(List<String> data) {
this.mDataset=data;
}
OnBindViewHolder中的代码
holder.textView.setText(mDataset.get(i));
getItemCount()中的代码
return mDataset.size();