android GridView 拖拽Item及滾屏實現

針對以前修改的，進行了再修改。
這次就能很好的實現了長按，然後向下拖動，背景的Item也向上的效果。
注要對如下函數進行了修改：
private void onDrag(int x, int y){if (dragImageView != null){windowParams.alpha = 0.6f;windowParams.x = x - dragPointX + dragOffsetX;windowParams.y = y - dragPointY + dragOffsetY;// L.l("=================windowParams.y=====000========"+windowParams.y);windowManager.updateViewLayout(dragImageView, windowParams);}int tempScrollX = x - dragPointX + dragOffsetX;int tempScrollY = y - dragPointY + dragOffsetY;int rangeY = itemHeight;int maxHeight = getHeight() - rangeY;int position = pointToPosition(x, y);int gridViewCount = this.getCount();int allContainCount = gridViewCount;int leftCount = gridViewCount % numColumns;if (leftCount != 0){allContainCount += (numColumns - leftCount);}int upMaxPosition = allContainCount - numColumns;L.l("==========position:" + position + "  max:" + upMaxPosition+ "  count:" + this.getChildCount() + "  rangy:" + rangeY);// 如果position大於最大的itemif (position >= upMaxPosition || position < numColumns){L.l("=====last line=======postion:" + position);setEnabled(false);}else{L.l("=====good========tempScrollY:" + tempScrollY + " rangeY:"+ rangeY + " maxHeight:" + maxHeight);if (tempScrollY < rangeY)// 假如漂浮的view已經進入第一行,則把當前的gridView滑出一個{L.l("=====gridView scroll down=======:" + tempScrollY);setEnabled(true);int position2 = getFirstVisiblePosition();smoothScrollToPosition(position2 - 1);// scrollTo(0, -itemHeight);}elseif (tempScrollY > maxHeight){L.l("=====gridView scroll up=======:" + tempScrollY);setEnabled(true);int position1 = getLastVisiblePosition();smoothScrollToPosition(position1 + 1);// scrollTo(0, itemHeight);}}}自此完全搞定Item拖拽。下載代碼連結:http://download.csdn.net/detail/synwith/4082316