Android使用ItemTouchHelper实现侧滑删除和拖拽
本文实例为大家分享了如何使用ItemTouchHelper实现侧滑删除和拖拽的具体代码，供大家参考，具体内容如下
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1. 定义一个简单bean类:
public class ImgText {
public int resId;
public String des;
}2. 实现一个RecyclerView.Adapter
public class SwipeRecyclerAdapter extends RecyclerView.Adapter{ private List mList; public SwipeRecyclerAdapter(List list) { mList = list; } @Override public MyHolder onCreateViewHolder(ViewGroup parent, int viewType) { View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_swipe_recycler, parent, false); return new MyHolder(view); } @Override public void onBindViewHolder(MyHolder holder, int position) { ImgText imgText = mList.get(position); holder.img.setImageResource(imgText.resId); holder.des.setText(imgText.des); } @Override public int getItemCount() { return mList.size(); } public class MyHolder extends RecyclerView.ViewHolder { private ImageView img; private TextView des; public MyHolder(View itemView) { super(itemView); img = (ImageView) itemView.findViewById(R.id.img); des = (TextView) itemView.findViewById(R.id.text); } } }
3.绘制分割线:
public class DividerItemDecoration extends RecyclerView.ItemDecoration {
private static final int[] ATTRS = new int[]{android.R.attr.listDivider};
public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;
public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL;
private Drawable mDivider;
private int mOrientation;
public DividerItemDecoration(Context context, int orientation) {
final TypedArray a = context.obtainStyledAttributes(ATTRS);
mDivider = a.getDrawable(0);
a.recycle();
setOrientation(orientation);
}
public void setOrientation(int orientation) {
if (orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST) {
throw new IllegalArgumentException("invalid orientation");
}
mOrientation = orientation;
}
@Override
public void onDraw(Canvas c, RecyclerView parent) {
if (mOrientation == VERTICAL_LIST) {
drawVertical(c, parent);
} else {
drawHorizontal(c, parent);
}
}
public void drawVertical(Canvas c, RecyclerView parent) {
final int left = parent.getPaddingLeft();
final int right = parent.getWidth() - parent.getPaddingRight();
final int childCount = parent.getChildCount();
for (int i = 0; i < childCount; i++) {
final View child = parent.getChildAt(i);
RecyclerView v = new RecyclerView(
parent.getContext());
final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
.getLayoutParams();
final int top = child.getBottom() + params.bottomMargin;
final int bottom = top + mDivider.getIntrinsicHeight();
mDivider.setBounds(left, top, right, bottom);
mDivider.draw(c);
}
}
public void drawHorizontal(Canvas c, RecyclerView parent) {
final int top = parent.getPaddingTop();
final int bottom = parent.getHeight() - parent.getPaddingBottom();
final int childCount = parent.getChildCount();
for (int i = 0; i < childCount; i++) {
final View child = parent.getChildAt(i);
final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
.getLayoutParams();
final int left = child.getRight() + params.rightMargin;
final int right = left + mDivider.getIntrinsicHeight();
mDivider.setBounds(left, top, right, bottom);
mDivider.draw(c);
}
}
@Override
public void getItemOffsets(Rect outRect, int itemPosition,
RecyclerView parent) {
if (mOrientation == VERTICAL_LIST) {
outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
} else {
outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
}
}
}4. 实现ItemTouchHelper.Callback接口:
public class SwipeCallbackextends ItemTouchHelper.Callback { private RecyclerView.Adapter mAdapter; private List mList; public SwipeCallback(RecyclerView.Adapter adapter, List list) { mAdapter = adapter; mList = list; } @Override public boolean isLongPressDragEnabled() { return true; } @Override public boolean isItemViewSwipeEnabled() { return true; } @Override public int getMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) { int dragFlag=ItemTouchHelper.UP|ItemTouchHelper.DOWN; int swipeFlags=ItemTouchHelper.END|ItemTouchHelper.START; return makeMovementFlags(dragFlag,swipeFlags); } //用于移动item的位置 @Override public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) { Collections.swap(mList, viewHolder.getAdapterPosition(), target.getAdapterPosition()); mAdapter.notifyItemMoved(viewHolder.getAdapterPosition(), target.getAdapterPosition()); return true; } //一般用于滑动删除 @Override public void onSwiped(RecyclerView.ViewHolder viewHolder, int direction) { mList.remove(viewHolder.getAdapterPosition()); mAdapter.notifyItemRemoved(viewHolder.getAdapterPosition()); } }
5.编写侧滑删除和拖拽Activity
public class SwipeRecyclerViewActivity extends AppCompatActivity {
private RecyclerView mRecyclerView;
private List mList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_swipe_recycler);
mRecyclerView= (RecyclerView) findViewById(R.id.recycler);
mList=new ArrayList<>();
for (int i = 0; i < 20; i++) {
ImgText it= new ImgText();
it.resId=R.mipmap.ic_launcher;
it.des=i+"侧滑删除文字";
mList.add(it);
}
final SwipeRecyclerAdapter adapter= new SwipeRecyclerAdapter(mList);
RecyclerView.LayoutManager manager= new LinearLayoutManager(this,LinearLayoutManager.VERTICAL,false);
mRecyclerView.setLayoutManager(manager);
mRecyclerView.setItemAnimator(new DefaultItemAnimator());
mRecyclerView.addItemDecoration(new DividerItemDecoration(this, DividerItemDecoration.VERTICAL_LIST));
mRecyclerView.setAdapter(adapter);
ItemTouchHelper swipeItemHelper= new ItemTouchHelper(new SwipeCallback<>(adapter,mList));
swipeItemHelper.attachToRecyclerView(mRecyclerView);
}
} 以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持创新互联。
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