Android开发-小技巧汇总

一.获取listview滚动距离（item高度相同）

 public int getScrollY(AbsListView view) {
        View c = view.getChildAt(0);
        if (c == null) {
            return 0;
        }
        int firstVisiblePosition = view.getFirstVisiblePosition();
        int top = c.getTop();
        return -top + firstVisiblePosition * c.getHeight();
    }

 

二.获取listview滚动距离（适用于item高度不同）

private int getScrollY(AbsListView listView) {
    View c = listView.getChildAt(0); //this is the first visible row
    int scrollY = -c.getTop();
    listViewItemHeights.put(listView.getFirstVisiblePosition(), c.getHeight());
    for (int i = 0; i < listView.getFirstVisiblePosition(); ++i) {
        if (listViewItemHeights.get(i) != null) // (this is a sanity check)
            scrollY += listViewItemHeights.get(i); //add all heights of the views that are gone
    }
    return scrollY;
}

 

三.获取listview中的item View视图

private View getItemView(int position, AbsListView listView) {
    final int firstListItemPosition = listView.getFirstVisiblePosition();
    final int lastListItemPosition = firstListItemPosition + listView.getChildCount() - 1;

    if (position < firstListItemPosition || position > lastListItemPosition) {
        return listView.getAdapter().getView(position, null, listView);
    } else {
        final int childIndex = position - firstListItemPosition;
        return listView.getChildAt(childIndex);
    }
}