自定义RecyclerView实现QQ侧滑删除按钮

【本文转载自Android 基于RecyclerView的Item侧滑删除】
通过自定义RecyclerView实现的效果为item左滑显示删除按钮，点击删除，暴露俩个接口用于调用。实测可用

这里贴出了自定义的RecyclerView,布局文件及ViewHolder没有贴出来

import android.content.Context;import android.support.annotation.Nullable;import android.support.v7.widget.RecyclerView;import android.util.AttributeSet;import android.view.MotionEvent;import android.view.VelocityTracker;import android.view.View;import android.view.animation.LinearInterpolator;import android.widget.RelativeLayout;import android.widget.Scroller;import android.widget.TextView;public class MyRecyclerView extends RecyclerView {    private Context mContext;    //上一次的触摸点    private int mLastX, mLastY;    //当前触摸的item的位置    private int mPosition;    //item对应的布局    private RelativeLayout mItemLayout;    //删除按钮    private TextView mDelete;    //最大滑动距离(即删除按钮的宽度)    private int mMaxLength;    //是否在垂直滑动列表    private boolean isDragging;    //item是在否跟随手指移动    private boolean isItemMoving;    //item是否开始自动滑动    private boolean isStartScroll;    //删除按钮状态   0：关闭 1：将要关闭 2：将要打开 3：打开    private int mDeleteBtnState;    //检测手指在滑动过程中的速度    private VelocityTracker mVelocityTracker;    private Scroller mScroller;    private OnItemClickListener mListener;    public MyRecyclerView(Context context) {        this(context, null);    }    public MyRecyclerView(Context context, @Nullable AttributeSet attrs) {        this(context, attrs, 0);    }    public MyRecyclerView(Context context, @Nullable AttributeSet attrs, int defStyle) {        super(context, attrs, defStyle);        mContext = context;        mScroller = new Scroller(context, new LinearInterpolator());        mVelocityTracker = VelocityTracker.obtain();    }    @Override    public boolean onTouchEvent(MotionEvent e) {        mVelocityTracker.addMovement(e);        int x = (int) e.getX();        int y = (int) e.getY();        switch (e.getAction()) {            case MotionEvent.ACTION_DOWN:                if (mDeleteBtnState == 0) {                    View view = findChildViewUnder(x, y);                    if (view == null) {                        return false;                    }                    MyViewHolder viewHolder = (MyViewHolder ) getChildViewHolder(view);                    mItemLayout = viewHolder.rv_News;                    mPosition = viewHolder.getAdapterPosition();                    mDelete = (TextView) mItemLayout.findViewById(R.id.tv_Delete);                    mMaxLength = mDelete.getWidth();                    mDelete.setOnClickListener(new OnClickListener() {                        @Override                        public void onClick(View v) {                            mListener.onDeleteClick(mPosition);                            mItemLayout.scrollTo(0, 0);                            mDeleteBtnState = 0;                        }                    });                } else if (mDeleteBtnState == 3) {                    mScroller.startScroll(mItemLayout.getScrollX(), 0, -mMaxLength, 0, 200);                    invalidate();                    mDeleteBtnState = 0;                    return false;                } else {                    return false;                }                break;            case MotionEvent.ACTION_MOVE:                int dx = mLastX - x;                int dy = mLastY - y;                int scrollX = mItemLayout.getScrollX();                if (Math.abs(dx) > Math.abs(dy)) {//左边界检测                    isItemMoving = true;                    if (scrollX + dx <= 0) {                        mItemLayout.scrollTo(0, 0);                        return true;                    } else if (scrollX + dx >= mMaxLength) {//右边界检测                        mItemLayout.scrollTo(mMaxLength, 0);                        return true;                    }                    mItemLayout.scrollBy(dx, 0);//item跟随手指滑动                }                break;            case MotionEvent.ACTION_UP:                if (!isItemMoving && !isDragging && mListener != null) {//item点击事件                    mListener.onItemClick(mItemLayout, mPosition);                }                isItemMoving = false;                mVelocityTracker.computeCurrentVelocity(1000);//计算手指滑动的速度                float xVelocity = mVelocityTracker.getXVelocity();//水平方向速度（向左为负）                float yVelocity = mVelocityTracker.getYVelocity();//垂直方向速度                int deltaX = 0;                int upScrollX = mItemLayout.getScrollX();                if (Math.abs(xVelocity) > 100 && Math.abs(xVelocity) > Math.abs(yVelocity)) {                    if (xVelocity <= -100) {//左滑速度大于100，则删除按钮显示                        deltaX = mMaxLength - upScrollX;                        mDeleteBtnState = 2;                    } else if (xVelocity > 100) {//右滑速度大于100，则删除按钮隐藏                        deltaX = -upScrollX;                        mDeleteBtnState = 1;                    }                } else {                    if (upScrollX >= mMaxLength / 2) {//item的左滑动距离大于删除按钮宽度的一半，则显示删除按钮                        deltaX = mMaxLength - upScrollX;                        mDeleteBtnState = 2;                    } else if (upScrollX < mMaxLength / 2) {//否则隐藏                        deltaX = -upScrollX;                        mDeleteBtnState = 1;                    }                }                //item自动滑动到指定位置                mScroller.startScroll(upScrollX, 0, deltaX, 0, 200);                isStartScroll = true;                invalidate();                mVelocityTracker.clear();                break;        }        mLastX = x;        mLastY = y;        return super.onTouchEvent(e);    }    @Override    public void computeScroll() {        if (mScroller.computeScrollOffset()) {            mItemLayout.scrollTo(mScroller.getCurrX(), mScroller.getCurrY());            invalidate();        } else if (isStartScroll) {            isStartScroll = false;            if (mDeleteBtnState == 1) {                mDeleteBtnState = 0;            }            if (mDeleteBtnState == 2) {                mDeleteBtnState = 3;            }        }    }    @Override    protected void onDetachedFromWindow() {        mVelocityTracker.recycle();        super.onDetachedFromWindow();    }    @Override    public void onScrollStateChanged(int state) {        super.onScrollStateChanged(state);        isDragging = state == SCROLL_STATE_DRAGGING;    }    public void setOnItemClickListener(OnItemClickListener listener) {        mListener = listener;    }    public interface OnItemClickListener {        /**         * item点击回调         *         * @param view         * @param position         */        void onItemClick(View view, int position);        /**         * 删除按钮回调         *         * @param position         */        void onDeleteClick(int position);    }}

代码到此为止，这个是在网上找了很多自定义RecyclerView实现侧滑删除里最好用的，如侵删。