本文实例为大家分享了Android Recyclerview实现左滑删除的具体代码，供大家参考，具体内容如下
1.先创建一个工具类
SlideRecyclerView
public class SlideRecyclerView extends RecyclerView {
private static final String TAG = "SlideRecyclerView";
private static final int INVALID_POSITION = -1; // 触摸到的点不在子View范围内
private static final int INVALID_CHILD_WIDTH = -1; // 子ItemView不含两个子View
private static final int SNAP_VELOCITY = 600; // 最小滑动速度
private VelocityTracker mVelocityTracker; // 速度追踪器
private int mTouchSlop; // 认为是滑动的最小距离（一般由系统提供）
private Rect mTouchFrame; // 子View所在的矩形范围
private Scroller mScroller;
private float mLastX; // 滑动过程中记录上次触碰点X
private float mFirstX, mFirstY; // 首次触碰范围
private boolean mIsSlide; // 是否滑动子View
private ViewGroup mFlingView; // 触碰的子View
private int mPosition; // 触碰的view的位置
private int mMenuViewWidth; // 菜单按钮宽度
public SlideRecyclerView(Context context) {
this(context, null);
}
public SlideRecyclerView(Context context, @Nullable AttributeSet attrs) {
this(context, attrs, 0);
}
public SlideRecyclerView(Context context, @Nullable AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
mScroller = new Scroller(context);
}
@Override
public boolean onInterceptTouchEvent(MotionEvent e) {
int x = (int) e.getX();
int y = (int) e.getY();
obtainVelocity(e);
switch (e.getAction()) {
case MotionEvent.ACTION_DOWN:
if (!mScroller.isFinished()) { // 如果动画还没停止，则立即终止动画
mScroller.abortAnimation();
}
mFirstX = mLastX = x;
mFirstY = y;
mPosition = pointToPosition(x, y); // 获取触碰点所在的position
if (mPosition != INVALID_POSITION) {
View view = mFlingView;
// 获取触碰点所在的view
mFlingView = (ViewGroup) getChildAt(mPosition - ((LinearLayoutManager) getLayoutManager()).findFirstVisibleItemPosition());
// 这里判断一下如果之前触碰的view已经打开，而当前碰到的view不是那个view则立即关闭之前的view，此处并不需要担动画没完成冲突，因为之前已经abortAnimation
if (view != null && mFlingView != view && view.getScrollX() != 0) {
view.scrollTo(0, 0);
}
// 这里进行了强制的要求，RecyclerView的子ViewGroup必须要有2个子view,这样菜单按钮才会有值，
// 需要注意的是:如果不定制RecyclerView的子View，则要求子View必须要有固定的width。
// 比如使用LinearLayout作为根布局，而content部分width已经是match_parent，此时如果菜单view用的是wrap_content，menu的宽度就会为0。
if (mFlingView.getChildCount() == 2) {
mMenuViewWidth = mFlingView.getChildAt(1).getWidth();
} else {
mMenuViewWidth = INVALID_CHILD_WIDTH;
}
}
break;
case MotionEvent.ACTION_MOVE:
mVelocityTracker.computeCurrentVelocity(1000);
// 此处有俩判断，满足其一则认为是侧滑：
// 1.如果x方向速度大于y方向速度，且大于最小速度限制；
// 2.如果x方向的侧滑距离大于y方向滑动距离，且x方向达到最小滑动距离；
float xVelocity = mVelocityTracker.getXVelocity();
float yVelocity = mVelocityTracker.getYVelocity();
if (Math.abs(xVelocity) > SNAP_VELOCITY && Math.abs(xVelocity) > Math.abs(yVelocity)
|| Math.abs(x - mFirstX) >= mTouchSlop
&& Math.abs(x - mFirstX) > Math.abs(y - mFirstY)) {
mIsSlide = true;
return true;
}
break;
case MotionEvent.ACTION_UP:
releaseVelocity();
break;
}
return super.onInterceptTouchEvent(e);
}
@Override
public boolean onTouchEvent(MotionEvent e) {
if (mIsSlide && mPosition != INVALID_POSITION) {
float x = e.getX();
obtainVelocity(e);
switch (e.getAction()) {
case MotionEvent.ACTION_DOWN: // 因为没有拦截，所以不会被调用到
break;
case MotionEvent.ACTION_MOVE:
// 随手指滑动
if (mMenuViewWidth != INVALID_CHILD_WIDTH) {
float dx = mLastX - x;
if (mFlingView.getScrollX() + dx <= mMenuViewWidth
&& mFlingView.getScrollX() + dx > 0) {
mFlingView.scrollBy((int) dx, 0);
}
mLastX = x;
}
break;
case MotionEvent.ACTION_UP:
if (mMenuViewWidth != INVALID_CHILD_WIDTH) {
int scrollX = mFlingView.getScrollX();
mVelocityTracker.computeCurrentVelocity(1000);
// 此处有两个原因决定是否打开菜单：
// 1.菜单被拉出宽度大于菜单宽度一半；
// 2.横向滑动速度大于最小滑动速度；
// 注意：之所以要小于负值，是因为向左滑则速度为负值
if (mVelocityTracker.getXVelocity() < -SNAP_VELOCITY) { // 向左侧滑达到侧滑最低速度，则打开
mScroller.startScroll(scrollX, 0, mMenuViewWidth - scrollX, 0, Math.abs(mMenuViewWidth - scrollX));
} else if (mVelocityTracker.getXVelocity() >= SNAP_VELOCITY) { // 向右侧滑达到侧滑最低速度，则关闭
mScroller.startScroll(scrollX, 0, -scrollX, 0, Math.abs(scrollX));
} else if (scrollX >= mMenuViewWidth / 2) { // 如果超过删除按钮一半，则打开
mScroller.startScroll(scrollX, 0, mMenuViewWidth - scrollX, 0, Math.abs(mMenuViewWidth - scrollX));
} else { // 其他情况则关闭
mScroller.startScroll(scrollX, 0, -scrollX, 0, Math.abs(scrollX));
}
invalidate();
}
mMenuViewWidth = INVALID_CHILD_WIDTH;
mIsSlide = false;
mPosition = INVALID_POSITION;
releaseVelocity(); // 这里之所以会调用，是因为如果前面拦截了，就不会执行ACTION_UP,需要在这里释放追踪
break;
}
return true;
} else {
// 此处防止RecyclerView正常滑动时，还有菜单未关闭
closeMenu();
// Velocity，这里的释放是防止RecyclerView正常拦截了，但是在onTouchEvent中却没有被释放；
// 有三种情况：1.onInterceptTouchEvent并未拦截，在onInterceptTouchEvent方法中，DOWN和UP一对获取和释放；
// 2.onInterceptTouchEvent拦截，DOWN获取，但事件不是被侧滑处理，需要在这里进行释放；
// 3.onInterceptTouchEvent拦截，DOWN获取，事件被侧滑处理，则在onTouchEvent的UP中释放。
releaseVelocity();
}
return super.onTouchEvent(e);
}
private void releaseVelocity() {
if (mVelocityTracker != null) {
mVelocityTracker.clear();
mVelocityTracker.recycle();
mVelocityTracker = null;
}
}
private void obtainVelocity(MotionEvent event) {
if (mVelocityTracker == null) {
mVelocityTracker = VelocityTracker.obtain();
}
mVelocityTracker.addMovement(event);
}
public int pointToPosition(int x, int y) {
if (null == getLayoutManager()) return INVALID_POSITION;
int firstPosition = ((LinearLayoutManager) getLayoutManager()).findFirstVisibleItemPosition();
Rect frame = mTouchFrame;
if (frame == null) {
mTouchFrame = new Rect();
frame = mTouchFrame;
}
final int count = getChildCount();
for (int i = count - 1; i >= 0; i--) {
final View child = getChildAt(i);
if (child.getVisibility() == View.VISIBLE) {
child.getHitRect(frame);
if (frame.contains(x, y)) {
return firstPosition + i;
}
}
}
return INVALID_POSITION;
}
@Override
public void computeScroll() {
if (mScroller.computeScrollOffset()) {
mFlingView.scrollTo(mScroller.getCurrX(), mScroller.getCurrY());
invalidate();
}
}
/**
* 将显示子菜单的子view关闭
* 这里本身是要自己来实现的，但是由于不定制item，因此不好监听器点击事件，因此需要调用者手动的关闭
*/
public void closeMenu() {
if (mFlingView != null && mFlingView.getScrollX() != 0) {
mFlingView.scrollTo(0, 0);
}
}
}
2.主布局
3.子布局
adapter_shoppingtrollery
4.适配器
ShoppingtrolleyAdapter
public class ShoppingtrolleyAdapter extends RecyclerView.Adapter{ Context context; List list; private OnItemClickListener mOnItemClickListener; public ShoppingtrolleyAdapter(Context context) { this.context = context; list = new ArrayList<>(); } public void setList(List list) { this.list = list; notifyDataSetChanged(); } public void setOnItemClickListener(OnItemClickListener onItemClickListener) { mOnItemClickListener = onItemClickListener; } public interface OnItemClickListener { void onItemClick(View view, int position); } @NonNull @NotNull @Override public ShoppingtrolleyAdapter.Myvh onCreateViewHolder(@NonNull @NotNull ViewGroup parent, int viewType) { View view = LayoutInflater.from(context).inflate(R.layout.adapter_shoppingtrollery,parent,false); return new ShoppingtrolleyAdapter.Myvh(view); } @SuppressLint("SetTextI18n") @Override public void onBindViewHolder(@NonNull @NotNull ShoppingtrolleyAdapter.Myvh holder, int position) { //左滑删除事件 holder.shoppingtrollery_delete.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if (mOnItemClickListener != null) { mOnItemClickListener.onItemClick(v, position); } } }); } @Override public int getItemCount() { return list.size(); } public class Myvh extends RecyclerView.ViewHolder { private final CheckBox shoppingtrollery_ischeck; private final ImageView shoppingtrollery_iv; private final TextView shoppingtrollery_name; private final TextView shoppingtrollery_type; private final TextView shoppingtrollery_price; private final TextView shoppingtrollery_subtract; private final TextView shoppingtrollery_count; private final TextView shoppingtrollery_add; private final TextView shoppingtrollery_delete; public Myvh(@NonNull @NotNull View itemView) { super(itemView); shoppingtrollery_ischeck = itemView.findViewById(R.id.shoppingtrollery_ischeck); shoppingtrollery_iv = itemView.findViewById(R.id.shoppingtrollery_iv); shoppingtrollery_name = itemView.findViewById(R.id.shoppingtrollery_name); shoppingtrollery_type = itemView.findViewById(R.id.shoppingtrollery_type); shoppingtrollery_price = itemView.findViewById(R.id.shoppingtrollery_price); shoppingtrollery_subtract = itemView.findViewById(R.id.shoppingtrollery_subtract); shoppingtrollery_count = itemView.findViewById(R.id.shoppingtrollery_count); shoppingtrollery_add = itemView.findViewById(R.id.shoppingtrollery_add); shoppingtrollery_delete = itemView.findViewById(R.id.shoppingtrollery_delete); } } }
5.主页代码
/**
* 购物车列表
*/
private void setlistdata() {
SlideRecyclerView shoppingtrolley_rv = findViewById(R.id.shoppingtrolley_rv);
// 创建布局管理
LinearLayoutManager layoutManager = new LinearLayoutManager(this);
layoutManager.setOrientation(LinearLayoutManager.VERTICAL);
shoppingtrolley_rv.setLayoutManager(layoutManager);
//模拟数据
List list = new ArrayList<>();
list.add("a");
list.add("a");
list.add("a");
list.add("a");
list.add("a");
ShoppingtrolleyAdapter shoppingtrolleyAdapter = new ShoppingtrolleyAdapter(this);
shoppingtrolleyAdapter.setList(list);
shoppingtrolley_rv.setAdapter(shoppingtrolleyAdapter);
//左滑删除
shoppingtrolleyAdapter.setOnItemClickListener(new ShoppingtrolleyAdapter.OnItemClickListener() {
@Override
public void onItemClick(View view, int position) {
list.remove(position);
shoppingtrolleyAdapter.notifyDataSetChanged();
//Toast.makeText(ShoppingtrolleyActivity.this, ""+position, Toast.LENGTH_SHORT).show();
}
});
}
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脚本之家。