Android GridView 拖拽Item及滾屏實現

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：

1. private void onDrag(int x, int y)
2. {
3. if (dragImageView != null)
4. {
5. windowParams.alpha = 0.6f;
6. windowParams.x = x - dragPointX + dragOffsetX;
7. windowParams.y = y - dragPointY + dragOffsetY;
8. // L.l("=================windowParams.y=====000========"+windowParams.y);
9. windowManager.updateViewLayout(dragImageView, windowParams);
10. }
12. int tempScrollX = x - dragPointX + dragOffsetX;
13. int tempScrollY = y - dragPointY + dragOffsetY;
15. int rangeY = itemHeight;
16. int maxHeight = getHeight() - rangeY;
18. int position = pointToPosition(x, y);
20. int gridViewCount = this.getCount();
21. int allContainCount = gridViewCount;
22. int leftCount = gridViewCount % numColumns;
23. if (leftCount != 0)
24. {
25. allContainCount += (numColumns - leftCount);
26. }
27. int upMaxPosition = allContainCount - numColumns;
28. L.l("==========position:" + position + " max:" + upMaxPosition
29. + " count:" + this.getChildCount() + " rangy:" + rangeY);
31. // 如果position大於最大的item
32. if (position >= upMaxPosition || position < numColumns)
33. {
35. L.l("=====last line=======postion:" + position);
36. setEnabled(false);
37. }
38. else
39. {
40. L.l("=====good========tempScrollY: " + tempScrollY + " rangeY:"
41. + rangeY + " maxHeight:" + maxHeight);
43. 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
44. {
45. L.l("=====gridView scroll down=======:" + tempScrollY);
46. setEnabled(true);
47. int position2 = getFirstVisiblePosition();
48. smoothScrollToPosition(position2 - 1);
49. // scrollTo(0, -itemHeight);
50. }
51. else
52. if (tempScrollY > maxHeight)
53. {
54. L.l("=====gridView scroll up=======:" + tempScrollY);
55. setEnabled(true);
56. int position1 = getLastVisiblePosition();
57. smoothScrollToPosition(position1 + 1);
58. // scrollTo(0, itemHeight);
59. }
60. }
62. }

自此完全搞定Item拖拽。