Android解析---DragGridView长按动态排序

       曾经项目需求，要实现一个类似以前ZAKER新闻阅读的DragGridView特效。不过，没要求实现横向跨屏，而是竖向跨屏。网上资源也很多，有实现横向跨屏的，可是没有找到竖向的。后来只好结合人家代码，修改一二。

贴代码！

/** * @blog http://blog.csdn.net/xiaanming *  * @author xiaanming&&wangxuanao *  */public class DragGridView extends GridView {/** * DragGridView的item长按响应的时间， 默认是1000毫秒，也可以自行设置。目前没有用到延迟。 */private long dragResponseMS = 1000;/** * 是否可以拖拽，默认不可以 */private boolean isDrag = false;private int mDownX;private int mDownY;private int moveX;private int moveY;private int nColumns = 2;/** * 是否计算状态栏的高度在内，涉及到镜像的起始位置y */private boolean isContainStatusHeight = false;private boolean isMoving = false;/** * 正在拖拽的position */private int mDragPosition;/** * 刚开始拖拽的item对应的View */private View mStartDragItemView = null;/** * 用于拖拽的镜像，这里直接用一个ImageView */private ImageView mDragImageView;/** * 震动器 */private Vibrator mVibrator;private WindowManager mWindowManager;/** * item镜像的布局参数 */private WindowManager.LayoutParams mWindowLayoutParams;/** * 我们拖拽的item对应的Bitmap */private Bitmap mDragBitmap;/** * 按下的点到所在item的上边缘的距离 */private int mPoint2ItemTop;/** * 按下的点到所在item的左边缘的距离 */private int mPoint2ItemLeft;/** * DragGridView距离屏幕顶部的偏移量 */private int mOffset2Top;/** * DragGridView距离屏幕左边的偏移量 */private int mOffset2Left;/** * 状态栏的高度 */private int mStatusHeight;/** * DragGridView自动向下滚动的边界值 */private int mDownScrollBorder;/** * DragGridView自动向上滚动的边界值 */private int mUpScrollBorder;/** * DragGridView自动滚动的速度 */private static final int speed = 20;public DragGridView(Context context) {this(context, null);}public DragGridView(Context context, AttributeSet attrs) {this(context, attrs, 0);}public DragGridView(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);mVibrator = (Vibrator) context.getSystemService(Context.VIBRATOR_SERVICE);mWindowManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);mStatusHeight = getStatusHeight(context); // 获取状态栏的高度}private Handler mHandler = new Handler();// 用来处理是否为长按的Runnableprivate Runnable mLongClickRunnable = new Runnable() {@Overridepublic void run() {isDrag = true; // 设置可以拖拽isMoving = false;mVibrator.vibrate(50); // 震动一下mStartDragItemView.setVisibility(View.INVISIBLE);// 隐藏该item// 根据我们按下的点显示item镜像createDragImage(mDragBitmap, mDownX, mDownY);}};/** * 设置响应拖拽的毫秒数，默认是1000毫秒 *  * @param dragResponseMS */public void setDragResponseMS(long dragResponseMS) {this.dragResponseMS = dragResponseMS;}/** * 长按检测事件 *  * @author wangxuanao */public boolean setOnItemLongClickListener(final MotionEvent ev) {this.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {@Overridepublic boolean onItemLongClick(AdapterView<?> arg0, View arg1,int arg2, long arg3) {// arg2和arg3一直是相等的。及点击的item的positionLog.e("LOG", "int arg2=" + arg2 + "     long arg3=" + arg3);mDownX = (int) ev.getX();mDownY = (int) ev.getY();// 获取所点击item的positionmDragPosition = arg2;if (mDragPosition == AdapterView.INVALID_POSITION) {Log.e("tag====onItemLongClick", "INVALID_POSITION");return true;}// 根据position获取该item所对应的ViewmStartDragItemView = getChildAt(mDragPosition- getFirstVisiblePosition());// 下面这几个距离大家可以参考我的博客上面的图来理解下mPoint2ItemTop = mDownY - mStartDragItemView.getTop();mPoint2ItemLeft = mDownX - mStartDragItemView.getLeft();mOffset2Top = (int) (ev.getRawY() - mDownY);mOffset2Left = (int) (ev.getRawX() - mDownX);// 获取DragGridView自动向上滚动的偏移量，小于这个值，DragGridView向下滚动mDownScrollBorder = getHeight() / 4;// 获取DragGridView自动向下滚动的偏移量，大于这个值，DragGridView向上滚动mUpScrollBorder = getHeight() * 3 / 4;// 开启mDragItemView绘图缓存mStartDragItemView.setDrawingCacheEnabled(true);// 获取mDragItemView在缓存中的Bitmap对象mDragBitmap = Bitmap.createBitmap(mStartDragItemView.getDrawingCache());// 这一步很关键，释放绘图缓存，避免出现重复的镜像mStartDragItemView.destroyDrawingCache();// 使用Handler延迟dragResponseMS执行mLongClickRunnable// mHandler.postDelayed(mLongClickRunnable, dragResponseMS);// 不延迟加载mHandler.post(mLongClickRunnable);return false;}});return super.onInterceptTouchEvent(ev);}@Overridepublic boolean onInterceptTouchEvent(MotionEvent ev) {if (ev.getAction() == MotionEvent.ACTION_DOWN) {return setOnItemLongClickListener(ev);}return super.onInterceptTouchEvent(ev);}@Overridepublic boolean onTouchEvent(MotionEvent ev) {// Log.e("LOG", "=========onTouchEvent=======");if (isDrag && mDragImageView != null) {switch (ev.getAction()) {case MotionEvent.ACTION_MOVE:moveX = (int) ev.getX();moveY = (int) ev.getY();// 拖动itemonDragItem(moveX, moveY);break;case MotionEvent.ACTION_UP:onStopDrag();isDrag = false;mHandler.removeCallbacks(mLongClickRunnable); // 线程结束mHandler.removeCallbacks(mScrollRunnable);break;}return true;}return super.onTouchEvent(ev);}/** * 创建拖动的镜像 *  * @param bitmap * @param downX *            按下的点相对父控件的X坐标 * @param downY *            按下的点相对父控件的X坐标 */private void createDragImage(Bitmap bitmap, int downX, int downY) {DragAdapter adapter = (DragAdapter) this.getAdapter();adapter.showDropItem(false);mWindowLayoutParams = new WindowManager.LayoutParams();mWindowLayoutParams.format = PixelFormat.TRANSLUCENT; // 图片之外的其他地方透明mWindowLayoutParams.gravity = Gravity.TOP | Gravity.LEFT;mWindowLayoutParams.x = downX - mPoint2ItemLeft + mOffset2Left;if (isContainStatusHeight) {mWindowLayoutParams.y = downY - mPoint2ItemTop + mOffset2Top- mStatusHeight; // 状态栏高度 可选} else {mWindowLayoutParams.y = downY - mPoint2ItemTop + mOffset2Top;}Log.e("tag", "mWindowLayoutParams   x=" + mWindowLayoutParams.x+ "   y=" + mWindowLayoutParams.y);mWindowLayoutParams.alpha = 0.55f; // 透明度mWindowLayoutParams.width = WindowManager.LayoutParams.WRAP_CONTENT;mWindowLayoutParams.height = WindowManager.LayoutParams.WRAP_CONTENT;mWindowLayoutParams.flags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE| WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE;mDragImageView = new ImageView(getContext());mDragImageView.setImageBitmap(bitmap);mWindowManager.addView(mDragImageView, mWindowLayoutParams);}/** * 从界面上面移动拖动镜像 */private void removeDragImage() {if (mDragImageView != null) {mWindowManager.removeView(mDragImageView);mDragImageView = null;}}/** * 拖动item，在里面实现了item镜像的位置更新，item的相互交换以及GridView的自行滚动 *  * @param x * @param y */private void onDragItem(int moveX, int moveY) {mWindowLayoutParams.x = moveX - mPoint2ItemLeft + mOffset2Left;if (isContainStatusHeight) {mWindowLayoutParams.y = moveY - mPoint2ItemTop + mOffset2Top- mStatusHeight;// 状态栏高度 可选} else {mWindowLayoutParams.y = moveY - mPoint2ItemTop + mOffset2Top;}mWindowManager.updateViewLayout(mDragImageView, mWindowLayoutParams); // 更新镜像的位置onSwapItem(moveX, moveY);// GridView自动滚动mHandler.post(mScrollRunnable);}/** * 当moveY的值大于向上滚动的边界值，触发GridView自动向上滚动 当moveY的值小于向下滚动的边界值，触犯GridView自动向下滚动 * 否则不进行滚动 */private Runnable mScrollRunnable = new Runnable() {@Overridepublic void run() {int scrollY;if (moveY > mUpScrollBorder) {scrollY = speed;mHandler.postDelayed(mScrollRunnable, 25);} else if (moveY < mDownScrollBorder) {scrollY = -speed;mHandler.postDelayed(mScrollRunnable, 25);} else {scrollY = 0;mHandler.removeCallbacks(mScrollRunnable);}// 当我们的手指到达GridView向上或者向下滚动的偏移量的时候，可能我们手指没有移动，但是DragGridView在自动的滚动// 所以我们在这里调用下onSwapItem()方法来交换itemonSwapItem(moveX, moveY);smoothScrollBy(scrollY, 10);}};/** * 交换item,并且控制item之间的显示与隐藏效果 *  * @param moveX * @param moveY */private void onSwapItem(int moveX, int moveY) {// 获取我们手指移动到的那个item的positionfinal int tempPosition = pointToPosition(moveX, moveY);// 假如tempPosition 改变了并且tempPosition不等于-1,则进行交换if (tempPosition != mDragPosition&& tempPosition != AdapterView.INVALID_POSITION) {// getChildAt(tempPosition -// getFirstVisiblePosition()).setVisibility(// View.INVISIBLE);// 拖动到了新的item,新的item隐藏掉//// getChildAt(mDragPosition - getFirstVisiblePosition())// .setVisibility(View.VISIBLE);// 之前的item显示出来if (!isMoving) {final int dropPosition = tempPosition- getFirstVisiblePosition();int dragPosition = mDragPosition - getFirstVisiblePosition();final int startPosition = mDragPosition;final int endPosition = tempPosition;Log.e("log", "tempPosition===" + tempPosition+ "   dropPosition===" + dropPosition+ "   dragPosition===" + dragPosition);int MoveNum = dropPosition - dragPosition;int holdPosition;if (dragPosition == dropPosition)MoveNum = 0;if (MoveNum != 0) {int itemMoveNum = Math.abs(MoveNum);float Xoffset, Yoffset;Log.e("log", "itemMoveNum===" + itemMoveNum);for (int i = 0; i < itemMoveNum; i++) {Log.e("log", "i===" + i);if (MoveNum > 0) {holdPosition = dragPosition + 1;Xoffset = (dragPosition / nColumns == holdPosition/ nColumns) ? (-1) : (nColumns - 1);Yoffset = (dragPosition / nColumns == holdPosition/ nColumns) ? 0 : (-1);} else {holdPosition = dragPosition - 1;Xoffset = (dragPosition / nColumns == holdPosition/ nColumns) ? 1 : (-(nColumns - 1));Yoffset = (dragPosition / nColumns == holdPosition/ nColumns) ? 0 : 1;}ViewGroup moveView = (ViewGroup) getChildAt(holdPosition);Log.e("log", "holdPosition===" + holdPosition);Animation animation = getMoveAnimation(Xoffset, Yoffset);moveView.startAnimation(animation);dragPosition = holdPosition;final DragAdapter adapter = (DragAdapter) this.getAdapter();isMoving = true;if (i == itemMoveNum - 1)animation.setAnimationListener(new Animation.AnimationListener() {@Overridepublic void onAnimationStart(Animation animation) {}@Overridepublic void onAnimationRepeat(Animation animation) {}@Overridepublic void onAnimationEnd(Animation animation) {adapter.exchange(startPosition,endPosition);isMoving = false;Log.e("log","isMoving=false====================================");}});}}}Log.e("log", "mDragPosition=" + mDragPosition+ "=====tempPosition=" + tempPosition);mDragPosition = tempPosition;}}/** * 动画交换交换item *  * @param dropPosition * @param dragPosition */public void OnMove(int dropPosition, int dragPosition) {}/** * 停止拖拽我们将之前隐藏的item显示出来，并将镜像移除 */private void onStopDrag() {// View view = getChildAt(mDragPosition - getFirstVisiblePosition());// if (view != null) {// view.setVisibility(View.VISIBLE);// }DragAdapter adapter = (DragAdapter) this.getAdapter();adapter.showDropItem(true);adapter.notifyDataSetChanged();removeDragImage();}/** * 获取状态栏的高度 *  * @param context * @return */private static int getStatusHeight(Context context) {int statusHeight = 0;Rect localRect = new Rect();((Activity) context).getWindow().getDecorView().getWindowVisibleDisplayFrame(localRect);statusHeight = localRect.top;if (0 == statusHeight) {Class<?> localClass;try {localClass = Class.forName("com.android.internal.R$dimen");Object localObject = localClass.newInstance();int i5 = Integer.parseInt(localClass.getField("status_bar_height").get(localObject).toString());statusHeight = context.getResources().getDimensionPixelSize(i5);} catch (Exception e) {e.printStackTrace();}}return statusHeight;}/** * 移动动画 *  * @author wangxuanao *  */public Animation getMoveAnimation(float x, float y) {TranslateAnimation go = new TranslateAnimation(Animation.RELATIVE_TO_SELF, 0, Animation.RELATIVE_TO_SELF, x,Animation.RELATIVE_TO_SELF, 0, Animation.RELATIVE_TO_SELF, y);go.setFillAfter(true);go.setDuration(300);return go;}}

运行截图：

       此demo支持长按滑动。支持动画效果，支持向下跨屏滑动。不过在跨屏滑动的时候存在bug。有兴趣的同学可以修改一下。源代码下载