获取 ListView 的滚动位置

main.java

public int getScrollY() {
    View c = mListView.getChildAt(0);
    if (c == null) {
        return 0;
    }

    int firstVisiblePosition = mListView.getFirstVisiblePosition();
    int top = c.getTop();

    int headerHeight = 0;
    if (firstVisiblePosition >= 1) {
        headerHeight = mPlaceHolderView.getHeight();
    }

    return -top + firstVisiblePosition * c.getHeight() + headerHeight;
}