先看看效果图
主要思想：
1、监听触碰事件
2、用WindowManager添加拖曳的图片
3、用Collections.swap()交换List数据
自定义代码：
public class DragGridVeiw extends GridView { private final int PRESS_TIME = 1000;//长按时间 private int mDownX;//触碰时的X坐标 private int mDownY;//触碰时的Y坐标 private int mMoveX;//移动时的X坐标 private int mMoveY;//移动时的Y坐标 private int mOffset2Top;//DragGridView距离屏幕顶部的偏移量 private int mOffset2Left;//DragGridView距离屏幕左边的偏移量 private int mPointToItemTop;//触碰点距离ItemView的上边距 private int mPointToItemLeft;//触碰点距离ItemView的左边距 private int mStatusHeight;//状态栏高度 private boolean isDraging;//是否正在拖曳 private Bitmap mBitmap;//ItemView的图片 private int mTouchPostiion;//触碰的位置 private View mTouchItemView;//触碰的ItemView private Vibrator mVibrator;//震动器 private ImageView mDragImageView;//拖曳的View private WindowManager mWindowManager;//窗口管理器 private WindowManager.LayoutParams mWindowLayoutParams;//窗口管理器布局 private OnChanageListener onChanageListener;//交换事件监听器 private Handler mHandler = new Handler(); public DragGridVeiw(Context context) { this(context, null); } public DragGridVeiw(Context context, AttributeSet attrs) { this(context, attrs, 0); } public DragGridVeiw(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); mStatusHeight = getStatusHeight(context); mVibrator = (Vibrator) context.getSystemService(Context.VIBRATOR_SERVICE); mWindowManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE); } @Override public boolean dispatchTouchEvent(MotionEvent ev) { switch (ev.getAction()) { case MotionEvent.ACTION_DOWN: //使用Handler延迟dragResponseMS执行mLongClickRunnable mHandler.postDelayed(mLongClickRunnable, PRESS_TIME); mDownX = (int) ev.getX(); mDownY = (int) ev.getY(); //根据按下的X,Y坐标获取所点击item的position mTouchPostiion = pointToPosition(mDownX, mDownY); if (mTouchPostiion == AdapterView.INVALID_POSITION) { return super.dispatchTouchEvent(ev); } //根据position获取该item所对应的View mTouchItemView = getChildAt(mTouchPostiion - 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 mPointToItemTop = mDownY - mTouchItemView.getTop(); mPointToItemLeft = mDownX - mTouchItemView.getLeft(); mOffset2Top = (int) (ev.getRawY() - mDownY); mOffset2Left = (int) (ev.getRawX() - mDownX); //开启mDragItemView绘图缓存 mTouchItemView.setDrawingCacheEnabled(true); //获取mDragItemView在缓存中的Bitmap对象 mBitmap = Bitmap.createBitmap(mTouchItemView.getDrawingCache()); //这一步很关键，释放绘图缓存，避免出现重复的镜像 mTouchItemView.destroyDrawingCache(); break; case MotionEvent.ACTION_MOVE: int moveX = (int) ev.getX(); int moveY = (int) ev.getY(); //拖曳点超出GridView区域则取消拖曳事件 if (ev.getY() > getHeight() || ev.getY() < 0) { onStopDrag(); } //如果我们在按下的item上面移动，只要超过item的边界就移除mRunnable if (!isTouchInItem(mTouchItemView, moveX, moveY)) { mHandler.removeCallbacks(mLongClickRunnable); } break; case MotionEvent.ACTION_UP: mHandler.removeCallbacks(mLongClickRunnable); break; } return super.dispatchTouchEvent(ev); } @Override public boolean onTouchEvent(MotionEvent ev) { if (isDraging && mDragImageView != null) { switch (ev.getAction()) { case MotionEvent.ACTION_MOVE: mMoveX = (int) ev.getX(); mMoveY = (int) ev.getY(); //拖动item onDragItem(mMoveX, mMoveY); break; case MotionEvent.ACTION_UP: onStopDrag(); break; } return true; } return super.onTouchEvent(ev); } //处理长按事件的线程 private Runnable mLongClickRunnable = new Runnable() { @Override public void run() { isDraging = true; //设置可以拖拽 mVibrator.vibrate(50); //震动一下 mTouchItemView.setVisibility(View.INVISIBLE);//隐藏该ItemView //根据我们按下的点显示ItemView镜像 createDragView(mBitmap, mDownX, mDownY); } }; //添加拖动View private void createDragView(Bitmap bitmap, int downX, int downY) { 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 - mPointToItemTop + mOffset2Left; mWindowLayoutParams.y = downY - mPointToItemTop + mOffset2Top - mStatusHeight; mWindowLayoutParams.alpha = 0.6f; //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); } private void removeDragView() { if (mDragImageView != null) { mWindowManager.removeView(mDragImageView); mDragImageView = null; } } //是否点击在GridView的item上面 private boolean isTouchInItem(View dragView, int x, int y) { int leftOffset = dragView.getLeft(); int topOffset = dragView.getTop(); if (x < leftOffset || x > leftOffset + dragView.getWidth()) { return false; } if (y < topOffset || y > topOffset + dragView.getHeight()) { return false; } return true; } //拖动事件处理 private void onDragItem(int moveX, int moveY) { mWindowLayoutParams.x = moveX - mPointToItemLeft + mOffset2Left; mWindowLayoutParams.y = moveY - mPointToItemTop + mOffset2Top - mStatusHeight; mWindowManager.updateViewLayout(mDragImageView, mWindowLayoutParams); //更新DragView的位置 onSwapItem(moveX, moveY);//Item的相互交换 } //交换item,并且控制item之间的显示与隐藏效果 private void onSwapItem(int moveX, int moveY) { //获取我们手指移动到的那个item的position 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 != mTouchPostiion && tempPosition != AdapterView.INVALID_POSITION) { getChildAt(tempPosition - getFirstVisiblePosition()).setVisibility(View.INVISIBLE);//拖动到了新的item,新的item隐藏掉 getChildAt(mTouchPostiion - getFirstVisiblePosition()).setVisibility(View.VISIBLE);//之前的item显示出来 if (onChanageListener != null) { onChanageListener.onChange(mTouchPostiion, tempPosition); } mTouchPostiion = tempPosition; } } //停止拖拽我们将之前隐藏的item显示出来，并将DragView移除 private void onStopDrag() { isDraging = false; getChildAt(mTouchPostiion - getFirstVisiblePosition()).setVisibility(View.VISIBLE); removeDragView(); } //Item交换事件监听 public void setOnChangeListener(OnChanageListener onChanageListener) { this.onChanageListener = onChanageListener; } //获取状态栏高度 private 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; } //当item交换位置的时候回调的方法，我们只需要在该方法中实现数据的交换即可 public interface OnChanageListener { public void onChange(int from, int to); } }
使用方法：
List<HashMap<String, Object>> dataSourceList = new ArrayList<>(); dragVeiw = (DragGridVeiw) findViewById(R.id.view_drag); for (int i = 0; i < 8; i++) { HashMap<String, Object> itemHashMap = new HashMap<>(); itemHashMap.put("item_image", R.drawable.sample_1); itemHashMap.put("item_text", "拖拽 " + Integer.toString(i)); dataSourceList.add(itemHashMap); } final SimpleAdapter mSimpleAdapter = new SimpleAdapter(this, dataSourceList, R.layout.item_drag, new String[]{"item_image", "item_text"}, new int[]{R.id.item_image, R.id.item_text}); dragVeiw.setAdapter(mSimpleAdapter); dragVeiw.setOnChangeListener(new DragGridVeiw.OnChanageListener() { @Override public void onChange(int from, int to) { HashMap<String, Object> temp = dataSourceList.get(from); //这里的处理需要注意下 if (from < to) { for (int i = from; i < to; i++) { Collections.swap(dataSourceList, i, i + 1); } } else if (from > to) { for (int i = from; i > to; i--) { Collections.swap(dataSourceList, i, i - 1); } } dataSourceList.set(to, temp); mSimpleAdapter.notifyDataSetChanged(); } });
附录：
Log.v("-->getWidth", String.valueOf(getWidth()));//DragView的宽度 Log.v("-->getHeight", String.valueOf(getHeight()));//DragView的高度 Log.v("-->getLeft", String.valueOf(getLeft()));//DragView左边距离屏幕左侧的长度 Log.v("-->getTop", String.valueOf(getTop()));///DragView上边距离屏幕顶部的长度 Log.v("-->getRawX", String.valueOf(ev.getRawX()));//触碰点相对于屏幕的X坐标 Log.v("-->getRawY", String.valueOf(ev.getRawY()));//触碰点相对于屏幕的Y坐标 Log.v("-->getX", String.valueOf(ev.getX()));//触碰点相对于DragView的X坐标 Log.v("-->getY", String.valueOf(ev.getY()));//触碰点相对于DragView的Y坐标 Log.v("-->getItemWidth", String.valueOf(mTouchItemView.getWidth()));//DragView中ItemView的宽度 Log.v("-->getItemHeight", String.valueOf(mTouchItemView.getHeight()));//DragView中ItemView的高度 Log.v("-->getItemLeft", String.valueOf(mTouchItemView.getLeft()));//DragView中ItemView左边距离DragView左侧的长度 Log.v("-->getItemTop", String.valueOf(mTouchItemView.getTop()));//DragView中ItemView上边距离DragView顶部的长度
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。