聊聊GridView实现拖拽排序及数据交互的问题聊聊GridView实现拖拽排序及数据

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：
文章图片

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
【聊聊GridView实现拖拽排序及数据交互的问题】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() {@Overridepublic 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() {@Overridepublic 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; }@Overridepublic 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); }@Overridepublic 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*/@Overridepublic 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 itemhideView = 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() {@Overridepublic 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() {@Overridepublic 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; }@Overridepublic void onInvalidated() {mChildCount = adapter.getCount(); }}; /*** 控制自动滚屏的动画监听器.*/private ValueAnimator.AnimatorUpdateListener animUpdateListener = new ValueAnimator.AnimatorUpdateListener() {@Overridepublic 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 = https://www.it610.com/article/((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); elsemGridView.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); }@Overrideprotected 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); }@Overrideprotected 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_FULLSCREENor View.SYSTEM_UI_FLAG_IMMERSIVE or View.SYSTEM_UI_FLAG_HIDE_NAVIGATIONsetContentView(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 = 3var 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：