GridView如何实现拖拽排序及数据交互

这篇文章主要介绍了GridView如何实现拖拽排序及数据交互，具有一定借鉴价值，感兴趣的朋友可以参考下，希望大家阅读完这篇文章之后大有收获，下面让小编带着大家一起了解一下。

在研究项目中的一个效果的时候，查找资料过程中发现有人有这么一种需求，就是GridView在实现拖拽排序的基础上，如果是两个GridView之间实现拖拽效果，并要实现数据交互。

一、效果图：

实现这个效果需要考虑的事情：

　　① 这个UI整体的构建以及事件的传递

　　② 如何实现View的共享，穿过边界

二、实现思路：

　　对于单个GridView的拖拽效果实现是参考网上的一篇文章，很抱歉没能及时保存地址，所以这里就不贴了。

　　整体实现： 一个容器（DragChessView）里放置两个DragView(可拖拽排序Item的View)，事件全部交给DragChessView去处理，然后由他去控制事件的分配和处理。在这个容器中还在这两个DragView上面覆盖一层FrameLayout，来放置要移动的那个View，然后根据手势去移动View。DragView里面进行View的动态交换以及数据交换。

三、实现代码：

1. DragChessView代码

public class DragChessView extends FrameLayout {    private GestureDetector detector;    /**     * 点击拖动     */    public static final int DRAG_WHEN_TOUCH = 0;    /**     * 长按拖动     */    public static final int DRAG_BY_LONG_CLICK = 1;    private int mDragMode = DRAG_WHEN_TOUCH;    private boolean hasSendDragMsg = false;    private Handler handler = new Handler(new Handler.Callback() {        @Override        public boolean handleMessage(Message msg) {            switch (msg.what) {                case 0x123:                    // 启动拖拽模式                    isDragable = true;                    // 根据点击的位置生成该位置上的view镜像                    if (isTouchInTop(msg.arg2)) {                        mDragTop.setCurrentDragPosition(msg.arg1);                        copyView(mDragTop);                    } else {                        mDragBottom.setCurrentDragPosition(msg.arg1);                        copyView(mDragBottom);                    }                    hasSendDragMsg = false;                    break;                default:                    break;            }            return false;        }    });    private boolean isDragable = true;    private float[] lastLocation = null;    private View mCopyView;    private OnTouchListener l;    // 转交给GridView一些常用监听器    private AdapterView.OnItemLongClickListener itemLongClickListener;    private int mTouchArea = 0;    private View dragSlider;    private Point mMovePoint; // 记录移动走向，上到下，还是下到上    /**     * @param itemClickListener     * @描述:item 转交给gridview一些常用监听器     */    public void setOnItemClickListener(AdapterView.OnItemClickListener itemClickListener) {        mDragBottom.setOnItemClickListener(itemClickListener);    }    /**     * 长按监听器自己触发,点击拖动模式不存在长按     *     * @param     */    public void setOnItemLongClickListener(AdapterView.OnItemLongClickListener itemLongClickListener) {        this.itemLongClickListener = itemLongClickListener;    }    private boolean canAddViewWhenDragChange = true;    private int mStartPoint;    private int START_DRAG_TOP = 0;    private int START_DRAG_BOTTOM = 1;    /**     * 手势监听器,滚动和单击     */    private GestureDetector.SimpleOnGestureListener simpleOnGestureListener = new GestureDetector.SimpleOnGestureListener() {        @Override        public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {            if (hasSendDragMsg) {                hasSendDragMsg = false;                handler.removeMessages(0x123);            }            if (isDragable && mCopyView != null) {                if (lastLocation == null && e1 != null) {                    lastLocation = new float[]{e1.getRawX(), e1.getRawY()};                }                if (lastLocation == null)                    lastLocation = new float[]{0, 0};                distanceX = lastLocation[0] - e2.getRawX();                distanceY = lastLocation[1] - e2.getRawY();                lastLocation[0] = e2.getRawX();                lastLocation[1] = e2.getRawY();                mCopyView.setX(mCopyView.getX() - distanceX);                mCopyView.setY(mCopyView.getY() - distanceY);                int to = eventToPosition(e2);                mCopyView.invalidate();                if (isDragInTop()) {                    if (isDragFromBottom()) {                        if (isDragBack(isDragInTop())) { //针对已经进入bottom区域，但是又返回来的情况                            mStartPoint = START_DRAG_BOTTOM; //切换，保证移动过程中只执行一次                            canAddViewWhenDragChange = true;                        }                        if (canAddViewWhenDragChange) {// 保证移动过程中，数据只有一次的添加                            mDragTop.addSwapView(mDragBottom.getSwapData());                            mDragBottom.removeSwapView();                            canAddViewWhenDragChange = false;                            if (hideView != null)                                hideView.setVisibility(VISIBLE);                        }                        if (mDragTop.isViewInitDone()) {                            mDragTop.setCurrentDragPosition(mDragTop.getGridChildCount() - 1);                            hideView = mDragTop.getGridChildAt(mDragTop.getCurrentDragPosition());                            if (hideView != null)                                hideView.setVisibility(INVISIBLE);                            mMovePoint = getDragViewCenterPoint(mDragTop);                        }                    }                    if (mDragTop.isViewInitDone())                        dragChangePosition(mDragTop, to);                } else {                    if (isDragFromTop()) {                        if (isDragBack(isDragInTop())) {                            mStartPoint = START_DRAG_TOP;                            canAddViewWhenDragChange = true;                        }                        if (canAddViewWhenDragChange) {                            mDragBottom.addSwapView(mDragTop.getSwapData());                            mDragTop.removeSwapView();                            canAddViewWhenDragChange = false;                            if (hideView != null)                                hideView.setVisibility(VISIBLE);                        }                        if (mDragBottom.isViewInitDone()) {                            mDragBottom.setCurrentDragPosition(mDragBottom.getGridChildCount() - 1);                            hideView = mDragBottom.getGridChildAt(mDragBottom.getCurrentDragPosition());                            if (hideView != null)                                hideView.setVisibility(INVISIBLE);                            Log.e("mMovePoint", mMovePoint.x + "-----------" + mMovePoint.y);                            mMovePoint = getDragViewCenterPoint(mDragBottom);                        }                    }                    if (mDragBottom.isViewInitDone())                        dragChangePosition(mDragBottom, to);                }            }            return true;        }        @Override        public void onShowPress(MotionEvent e) {            /** 响应长按拖拽 */            if (mDragMode == DRAG_BY_LONG_CLICK) {                // 启动拖拽模式                // isDragable = true;                // 通知父控件不拦截我的事件                getParent().requestDisallowInterceptTouchEvent(true);                // 根据点击的位置生成该位置上的view镜像                int position = eventToPosition(e);                if (isCanDragMove(isTouchInTop(e) ? mDragTop : mDragBottom, position)) {                    // copyView(currentDragPosition = position);                    Message msg = handler.obtainMessage(0x123, position, (int) e.getY());                    // showpress本身大概需要170毫秒                    handler.sendMessageDelayed(msg, dragLongPressTime - 170);                    mMovePoint = new Point((int) e.getX(), (int) e.getY());                    mStartPoint = isTouchInTop(e) ? START_DRAG_TOP : START_DRAG_BOTTOM;                    hasSendDragMsg = true;                }            }        }    };    private boolean isDragBack(boolean dragInTop) {        return (dragInTop && mStartPoint == START_DRAG_TOP) || (!dragInTop && mStartPoint == START_DRAG_BOTTOM);    }    private boolean isDragFromTop() {        if (mMovePoint != null && mDragTop != null) {            if ((mMovePoint.x > mDragTop.getX() && mMovePoint.x < (mDragTop.getX() + mDragTop.getWidth())) 　　　　　　　　　　&& (mMovePoint.y > mDragTop.getY() && mMovePoint.y < (mDragTop.getY() + mDragTop.getHeight()))) {                return true;            }        }        return false;    }    private Point getDragViewCenterPoint(DragView dragView) {        Point result = new Point();        if (dragView != null) {            int height = dragView.getHeight();            int width = dragView.getWidth();            float x = dragView.getX();            float y = dragView.getY();            result.set((int) (x + width / 2), (int) (y + height / 2));        }        return result;    }    private boolean isDragFromBottom() {        if (mMovePoint != null && mDragBottom != null) {            if ((mMovePoint.x > mDragBottom.getX() && mMovePoint.x < (mDragBottom.getX() + mDragBottom.getWidth())) 　　　　　　　　　　　&& (mMovePoint.y > mDragBottom.getY() && mMovePoint.y < (mDragBottom.getY() + mDragBottom.getHeight()))) {                return true;            }        }        return false;    }    private boolean isTouchInTop(MotionEvent event) {        float y = event.getY();        return isTouchInTop(y);    }    private boolean isTouchInTop(float y) {        return y > mDragTop.getY() && y < (mDragTop.getY() + mDragTop.getHeight());    }private void dragChangePosition(DragView dragView, int to) {        if (to != dragView.getCurrentDragPosition() && isCanDragMove(dragView, to)) {            dragView.onDragPositionChange(dragView.getCurrentDragPosition(), to);        }    }    private boolean isCanDragMove(DragView dragView, int position) {        return position >= dragView.getHeadDragPosition() && position < dragView.getGridChildCount() - dragView.getFootDragPosition();    }    private FrameLayout mDragFrame;    private DragView mDragBottom;    private DragView mDragTop;    private View hideView;    private long dragLongPressTime = 600;    public DragChessView(@NonNull Context context) {        this(context, null);    }    public DragChessView(@NonNull Context context, @Nullable AttributeSet attrs) {        this(context, attrs, -1);    }    public DragChessView(@NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);        init(attrs);    }    private void init(AttributeSet attrs) {        Context context = getContext();        detector = new GestureDetector(context, simpleOnGestureListener);        detector.setIsLongpressEnabled(false);        mDragFrame = new FrameLayout(context);        dragSlider = LayoutInflater.from(context).inflate(R.layout.layout_drag_chess, this, false);        mDragTop = dragSlider.findViewById(R.id.drag_top);        mDragBottom = dragSlider.findViewById(R.id.drag_bottom);        addView(dragSlider, -1, -1);        addView(mDragFrame, -1, -1);    }    @Override    public boolean onTouchEvent(MotionEvent ev) {        if (l != null) {            l.onTouch(this, ev);        }        if (!isViewInitDone()) {            return false;        }        if (isDragable) {            handleScrollAndCreMirror(ev);        } else {            // 交给子控件自己处理            dispatchEvent(isTouchInTop(ev) ? mDragTop : mDragBottom, ev);        }        // 处理拖动        detector.onTouchEvent(ev);        if (ev.getAction() == MotionEvent.ACTION_CANCEL || ev.getAction() == MotionEvent.ACTION_UP) {            lastLocation = null;            if (hasSendDragMsg) {                hasSendDragMsg = false;                handler.removeMessages(0x123);            }        }        return true;    }    private void dispatchEvent(DragView dragView, MotionEvent ev) {        dragView.dispatchEvent(ev);    }    private boolean isDragInTop() {        if (mCopyView == null)            return false;        return (mCopyView.getY() + mCopyView.getHeight()) < (mDragTop.getY() + mDragTop.getBottom());    }    /**     * Description :拦截所有事件     */    @Override    public boolean onInterceptTouchEvent(MotionEvent ev) {        return true;    }    /**     * 处理自动滚屏,和单击生成镜像     */    private void handleScrollAndCreMirror(MotionEvent ev) {        switch (ev.getAction()) {            case MotionEvent.ACTION_DOWN:                // 通知父控件不拦截我的事件                getParent().requestDisallowInterceptTouchEvent(true);                // 根据点击的位置生成该位置上的view镜像                int position = eventToPosition(ev);                makeCopyView(isTouchInTop(ev) ? mDragTop : mDragBottom, position);                break;            case MotionEvent.ACTION_MOVE:                getParent().requestDisallowInterceptTouchEvent(true);// 通知父控件不拦截我的事件                // 内容太多时,移动到边缘会自动滚动                decodeScrollArea(isDragInTop() ? mDragTop : mDragBottom, ev);                break;            case MotionEvent.ACTION_CANCEL:            case MotionEvent.ACTION_UP:                if (hideView != null) {                    hideView.setVisibility(View.VISIBLE);                    if (onDragSelectListener != null) {                        onDragSelectListener.onPutDown(hideView);                    }                }                mDragFrame.removeAllViews();                // mDragFrame.scrollTo(0, 0);                // isNotifyByDragSort = true;                updateUI(isDragInTop() ? mDragTop : mDragBottom, ev);                mCopyView = null;                canAddViewWhenDragChange = true;                // 放手时取消拖动排序模式                if (mDragMode == DRAG_BY_LONG_CLICK) {                    isDragable = false;                }                break;            default:                break;        }    }    private void updateUI(DragView dragView, MotionEvent ev) {        if (dragView.isHasPositionChange()) {            dragView.setHasPositionChange(false);            dragView.getAdapter().notifyDataSetChanged();        } else if (mDragMode == DRAG_BY_LONG_CLICK && itemLongClickListener != null) {            dragView.onItemLongClick(itemLongClickListener);        }        // 停止滚动        if (dragView.isCanScroll()) {            int scrollStates2 = dragView.decodeTouchArea(ev);            if (scrollStates2 != 0) {                dragView.onTouchAreaChange(0);                mTouchArea = 0;            }        }    }    private void decodeScrollArea(DragView dragView, MotionEvent ev) {        if (dragView.isCanScroll()) {            int touchArea = dragView.decodeTouchArea(ev);            if (touchArea != mTouchArea) {                dragView.onTouchAreaChange(touchArea);                mTouchArea = touchArea;            }        }    }    private void makeCopyView(DragView dragView, int position) {        if (position >= dragView.getHeadDragPosition() && position < dragView.getGridChildCount() - dragView.getFootDragPosition()) {            dragView.setCurrentDragPosition(position);            copyView(dragView);        }    }    /**     * 得到事件触发点, 摸到的是哪一个item     */    public int eventToPosition(MotionEvent ev) {        if (ev != null) {            if (isTouchInTop(ev))                return mDragTop.eventToPosition(ev);            return mDragBottom.eventToPosition(ev);        }        return 0;    }    /**     * 复制一个镜像,并添加到透明层     */    private void copyView(DragView dragView) {        // TODO: 2018/4/2 创建可移动的 item        hideView = dragView.getGridChildAt(dragView.getCurrentDragPosition());        int realPosition = dragView.getGridChildPos(hideView);        DragAdapter adapter = dragView.getAdapter();        if (!adapter.isUseCopyView()) {            mCopyView = adapter.getView(realPosition, mCopyView, mDragFrame);        } else {            mCopyView = adapter.copyView(realPosition, mCopyView, mDragFrame);        }        hideView.setVisibility(View.INVISIBLE);        if (mCopyView.getParent() == null)            mDragFrame.addView(mCopyView, dragView.getmColWidth(), dragView.getmColHeight());        int[] l1 = new int[2];        int[] l2 = new int[2];        hideView.getLocationOnScreen(l1);        mDragFrame.getLocationOnScreen(l2);        // mCopyView.setX(hideView.getLeft());        // mCopyView.setY(hideView.getTop() - mCurrentY);        mCopyView.setX(l1[0] - l2[0]);        mCopyView.setY(l1[1] - l2[1]);        if (onDragSelectListener == null) {            mCopyView.setScaleX(1.2f);            mCopyView.setScaleY(1.2f);        } else {            onDragSelectListener.onDragSelect(mCopyView);        }    }    private DragSortGridView.OnDragSelectListener onDragSelectListener;    /**     * @描述:一个item view刚被拖拽和放下时起来生成镜像时调用.     */    public void setOnDragSelectListener(DragSortGridView.OnDragSelectListener onDragSelectListener) {        this.onDragSelectListener = onDragSelectListener;    }    /**     * @param mode int类型     * @描述:设置拖动的策略是点击还是长按     */    public void setDragModel(int mode) {        this.mDragMode = mode;        isDragable = mode == DRAG_WHEN_TOUCH;    }    public void setAnimFrame(ListenFrameLayout mDragFrame) {        this.mDragFrame = mDragFrame;    }    /**     * 设置长按需要用时     *     * @param time     */    public void setDragLongPressTime(long time) {        dragLongPressTime = time;    }    public void setBottomAdapter(@NotNull DragAdapter adapter) {        mDragBottom.setAdapter(adapter);    }    public boolean isViewInitDone() {        boolean result = mDragBottom.isViewInitDone();        if (mDragTop.getVisibility() == VISIBLE)            result &= mDragTop.isViewInitDone();        return result;    }    public void setTopAdapter(@NotNull DragAdapter adapter) {        mDragTop.setAdapter(adapter);    }}

2. DragView的实现：

public class DragView extends FrameLayout {    private static final int TAG_KEY = R.id.first;    private NoScrollGridView mGridView;    private List mChilds = new ArrayList();    protected int mNumColumns = 3;    protected int mColHeight = 0;    protected int mColWidth = 0;    protected int mChildCount = 0;    protected int mMaxHeight = 0;    private boolean isViewInitDone = false;    private ListenScrollView mScrollView;    private int mCurrentY = 0;    /**     * 自动滚屏的动画     */    private ValueAnimator animator;    private DragAdapter adapter;    private int headDragPosition = 0;    private int footDragPosition = 0;    private int currentDragPosition = -1;    /**     * 是否有位置发生改变,否则不用重绘     */    private boolean hasPositionChange = false;    /**     * gridview能否滚动,是否内容太多     */    private boolean canScroll = true;    /**     * 动画时间     */    private static final long ANIM_DURING = 250;    private Object swapeData;    public DragView(@NonNull Context context) {        this(context, null);    }    public DragView(@NonNull Context context, @Nullable AttributeSet attrs) {        this(context, attrs, -1);    }    public DragView(@NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);        init();    }    private void init() {        Context context = getContext();        mGridView = new NoScrollGridView(context);        mGridView.setVerticalScrollBarEnabled(false);        mGridView.setStretchMode(GridView.STRETCH_COLUMN_WIDTH);        mGridView.setSelector(new ColorDrawable());        // View的宽高之类必须在测量,布局,绘制一系列过程之后才能获取到        mGridView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {            @Override            public void onGlobalLayout() {                if (mChilds.isEmpty()) {                    for (int i = 0; i < mGridView.getChildCount(); i++) {                        View view = mGridView.getChildAt(i);                        view.setTag(TAG_KEY, new int[]{0, 0});                        view.clearAnimation();                        mChilds.add(view);                    }                }                if (!mChilds.isEmpty()) {                    mColHeight = mChilds.get(0).getHeight();                }                mColWidth = mGridView.getColumnWidth();                if (mChildCount % mNumColumns == 0) {                    mMaxHeight = mColHeight * mChildCount / mNumColumns;                } else {                    mMaxHeight = mColHeight * (mChildCount / mNumColumns + 1);                }                canScroll = mMaxHeight - getHeight() > 0;                // 告知事件处理,完成View加载,许多属性也已经初始化了                isViewInitDone = true;            }        });        mScrollView = new ListenScrollView(context);        mGridView.setNumColumns(mNumColumns);        mScrollView.addView(mGridView, -1, -1);        addView(mScrollView, -1, -1);    }    private DataSetObserver observer = new DataSetObserver() {        @Override        public void onChanged() {            mChildCount = adapter.getCount();            // 下列属性状态清除,才会在被调用notifyDataSetChange时,在gridview测量布局完成后重新获取            mChilds.clear();            mColHeight = mColWidth = mMaxHeight = 0;            isViewInitDone = false;        }        @Override        public void onInvalidated() {            mChildCount = adapter.getCount();        }    };    /**     * 控制自动滚屏的动画监听器.     */    private ValueAnimator.AnimatorUpdateListener animUpdateListener = new ValueAnimator.AnimatorUpdateListener() {        @Override        public void onAnimationUpdate(ValueAnimator animation) {            int targetY = Math.round((Float) animation.getAnimatedValue());            if (targetY < 0) {                targetY = 0;            } else if (targetY > mMaxHeight - getHeight()) {                targetY = mMaxHeight - getHeight();            }            // mGridView.scrollTo(0, targetY);            mScrollView.smoothScrollTo(0, targetY);            // mCurrentY = targetY;        }    };    public void setAdapter(DragAdapter adapter) {        if (this.adapter != null && observer != null) {            this.adapter.unregisterDataSetObserver(observer);        }        this.adapter = adapter;        mGridView.setAdapter(adapter);        adapter.registerDataSetObserver(observer);        mChildCount = adapter.getCount();    }    /**     * @param from     * @param to     * @描述:动画效果移动View     */    public void translateView(int from, int to) {        View view = mChilds.get(from);        int fromXValue = ((int[]) view.getTag(TAG_KEY))[0];        int fromYValue = ((int[]) view.getTag(TAG_KEY))[1];        int toXValue = to % mNumColumns - from % mNumColumns + fromXValue;        int toYValue = to / mNumColumns - from / mNumColumns + fromYValue;        Animation animation = new TranslateAnimation(1, fromXValue, 1, toXValue, 1, fromYValue, 1, toYValue);        animation.setDuration(ANIM_DURING);        animation.setFillAfter(true);        view.setTag(TAG_KEY, new int[]{toXValue, toYValue});        view.startAnimation(animation);    }    /**     * @param from     * @param to     * @描述:拖动View使位置发生改变时     */    public void onDragPositionChange(int from, int to) {        if (from > to) {            for (int i = to; i < from; i++) {                translateView(i, i + 1);            }        } else {            for (int i = to; i > from; i--) {                translateView(i, i - 1);            }        }        if (!hasPositionChange) {            hasPositionChange = true;        }        if ((from >= mChilds.size() || from < 0) || (to >= mChilds.size() || to < 0))            return;        adapter.onDataModelMove(from, to);        View view = mChilds.remove(from);        mChilds.add(to, view);        currentDragPosition = to;    }    /**     * @param scrollStates     * @描述:触摸区域改变,做相应处理,开始滚动或停止滚动     */    public void onTouchAreaChange(int scrollStates) {        if (!canScroll) {            return;        }        if (animator != null) {            animator.removeUpdateListener(animUpdateListener);        }        if (scrollStates == 1) {// 从普通区域进入触发向上滚动的区域            int instance = mMaxHeight - getHeight() - mCurrentY;            animator = ValueAnimator.ofFloat(mCurrentY, mMaxHeight - getHeight());            animator.setDuration((long) (instance / 0.5f));            animator.setTarget(mGridView);            animator.addUpdateListener(animUpdateListener);            animator.start();        } else if (scrollStates == -1) {// 进入触发向下滚动的区域            animator = ValueAnimator.ofFloat(mCurrentY, 0);            animator.setDuration((long) (mCurrentY / 0.5f));            animator.setTarget(mGridView);            animator.addUpdateListener(animUpdateListener);            animator.start();        }    }    /**     * @param ev 事件     * @return 0中间区域, 1底部,-1顶部     * @描述: 检查当前触摸事件位于哪个区域, 顶部1/5可能触发下滚,底部1/5可能触发上滚     */    public int decodeTouchArea(MotionEvent ev) {        if (ev.getY() > (getHeight() + getY()) * 4 / (double) 5) {            return 1;        } else if (ev.getY() < (getHeight() + getY()) / (double) 5) {            return -1;        } else {            return 0;        }    }    public boolean isViewInitDone() {        return isViewInitDone;    }    /**     * 设置前几个item不可以改变位置     */    public void setNoPositionChangeItemCount(int count) {        headDragPosition = count;    }    /**     * 设置后几个item不可以改变位置     */    public void setFootNoPositionChangeItemCount(int count) {        footDragPosition = count;    }    public int getHeadDragPosition() {        return headDragPosition;    }    public int getFootDragPosition() {        return footDragPosition;    }    public int getGridChildCount() {        return mChilds.size();    }    public View getGridChildAt(int position) {        if (position < 0 || position >= mChilds.size())            return null;        return mChilds.get(position);    }    public int getGridChildPos(View view) {        return mGridView.indexOfChild(view);    }    public void setCurrentDragPosition(int currentDragPosition) {        this.currentDragPosition = currentDragPosition;    }    public int getCurrentDragPosition() {        return currentDragPosition;    }    public int getmColHeight() {        return mColHeight;    }    public int getmColWidth() {        return mColWidth;    }    public DragAdapter getAdapter() {        return adapter;    }    public boolean isHasPositionChange() {        return hasPositionChange;    }    public void setHasPositionChange(boolean hasPositionChange) {        this.hasPositionChange = hasPositionChange;    }    public boolean isCanScroll() {        return canScroll;    }    public void setOnItemClickListener(AdapterView.OnItemClickListener onItemClickListener) {        mGridView.setOnItemClickListener(onItemClickListener);    }    public void onItemLongClick(AdapterView.OnItemLongClickListener itemLongClickListener) {        itemLongClickListener.onItemLongClick(mGridView, childAt(currentDragPosition), currentDragPosition, 0);    }    public View childAt(int index) {        return mGridView.getChildAt(index);    }    public void dispatchEvent(MotionEvent ev) {        if (canScroll)            mScrollView.dispatchTouchEvent(ev);        else            mGridView.dispatchTouchEvent(ev);    }    public int eventToPosition(MotionEvent ev) {        if (ev != null) {            int m = (int) ev.getX() / mColWidth;            int n = (int) (ev.getY() - getY() + mCurrentY) / mColHeight;            int position = n * mNumColumns + m;            if (position >= mChildCount) {                return mChildCount - 1;            } else {                return position;            }        }        return 0;    }    public void addSwapView(Object data) {        adapter.addNewData(data);    }    public Object getSwapData() {        return adapter.getSwapData(currentDragPosition);    }    public void removeSwapView() {        if (adapter != null) {            adapter.removeData(currentDragPosition);            adapter.notifyDataSetChanged();        }    }    class ListenScrollView extends ScrollView {        public ListenScrollView(Context context) {            super(context);        }        @Override        protected void onScrollChanged(int l, int t, int oldl, int oldt) {            super.onScrollChanged(l, t, oldl, oldt);            mCurrentY = getScrollY();        }    }    class NoScrollGridView extends GridView {        public NoScrollGridView(Context context) {            super(context);        }        /**         * @return         * @描述:兼容老版本的getColumWidth         * @作者 [pWX273343] 2015年7月1日         */        public int getColumnWidth() {            return getWidth() / getNumColumns();        }        public NoScrollGridView(Context context, AttributeSet attrs) {            super(context, attrs);        }        @Override        protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {            int mExpandSpec = MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE >> 2, MeasureSpec.AT_MOST);            super.onMeasure(widthMeasureSpec, mExpandSpec);        }    }}

3. DragAdapter的代码：

public abstract class DragAdapter extends BaseAdapter {    /**     * @param from     * @param to     * @描述:当从from排序被拖到to排序时的处理方式,请对相应的数据做处理。     */    public abstract void onDataModelMove(int from, int to);    /**     * 复制View使用的方法,默认直接使用getView方法获取     *     * @param position     * @param convertView     * @param parent     * @return     */    public View copyView(int position, View convertView, ViewGroup parent) {        return null;    }    /**     * 是否启用copyView方法     *     * @return true 使用copyView复制 false 使用getView直接获取镜像     */    public boolean isUseCopyView() {        return false;    }    public abstract Object getSwapData(int position);    public abstract void removeData(int position);    public void addNewData(Object data) {    }}

4.使用MainActivity:

class GridDragShortActivity : AppCompatActivity() {    override fun onCreate(savedInstanceState: Bundle?) {        super.onCreate(savedInstanceState)        window.attributes.systemUiVisibility = View.SYSTEM_UI_FLAG_FULLSCREEN or View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN 　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　or View.SYSTEM_UI_FLAG_IMMERSIVE or View.SYSTEM_UI_FLAG_HIDE_NAVIGATION        setContentView(R.layout.activity_grid_drag_short)        //长按item响应该item的拖动排序,默认是触摸就开始拖动        drag_main.setDragModel(DragSortGridView.DRAG_BY_LONG_CLICK)        //设置每行个数//        drag_main.numColumns = 3        var arrayList = ArrayList()        var list = ArrayList()        for (i in 0..29) {            arrayList.add("" + i)        }        for (i in 0..29) {            list.add(('A' + i).toString())        }        drag_main.setBottomAdapter(CustomAdapter(list, this))        drag_main.setTopAdapter(CustomAdapter(arrayList, this))    }}

布局：activity_main.xml

布局 layout_drag_chess.xml:

在实际使用中，可以更据需要再去拓展使用，代码演变过程中的另一个效果，来看看，以它结束这篇：

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