android - Android Expandable ListView-如何平滑滚动到组内的子位置？

我有一个可扩展的列表视图。我的一个小组，第一组，有15个孩子。如何在单击并展开Group1时平滑滚动到第10个孩子？
谢谢。

最佳答案

重写适配器的onGroupExpanded方法并调用其中一个smoothScrollToPosition方法。类似于：

@Override
public void onGroupExpanded(int groupPosition) {
    super.onGroupExpanded(groupPosition);
    // If it's the first group
    if (groupPosition == 0) {
        int scrollTo = groupPosition + 15;
        mExpList.smoothScrollToPositionFromTop(scrollTo, 0);
    }
}

现在请记住，如果在ExpandableListView之前有其他组扩展，groupPosition将必须考虑到这一点。因此，您可能希望将所有展开的组位置（及其子级计数）保存到一个数组中，并在每次调用scrollTo和onGroupExpanded时循环它们。
可能是这样的：

@Override
public void onGroupExpanded(int groupPosition) {
    super.onGroupExpanded(groupPosition);
    groupStates.put(groupPosition, 1);
    childrenCount.put(groupPosition, getChildrenCount(groupPosition));
    // Loop the group states
    int scrollTo = 0;
    for (int i=0; i<groupStates.size(); i++) {
        int position = groupStates.keyAt(i);
        // Cancel the loop if reached a further expanded group
        if (position > groupPosition) break;

        // 1 is the group to be skipped + its children count
        scrollTo += 1 + childrenCount.get(position);
    }
    // You can select specific child of the recently expanded group, to scroll to
    int childToScrollTo = 15; // make sure is an existing child
    // -1 because positions begin at index 1
    scrollTo = scrollTo - 1 + childToScrollTo;
    mExpList.smoothScrollToPositionFromTop(scrollTo, 0);
}

@Override
public void onGroupCollapsed(int groupPosition) {
    super.onGroupCollapsed(groupPosition);
    groupStates.remove(groupPosition);
    childrenCount.remove(groupPosition);
}

但这是未经测试，所以请确保您测试它正确。