调用notifyDataSetChanged后在ListView中保留位置 [英] Retaining position in ListView after calling notifyDataSetChanged

问题描述

当用户滚动到底部时，我使用 OnScrollListener 将项目动态添加到 ListView.在我将数据添加到适配器并调用 notifyDataSetChanged 之后，ListView 返回到顶部.理想情况下，我想保留在 ListView 中的位置.关于我应该如何做这件事的任何想法?

I'm using an OnScrollListener to dynamically add items to a ListView when the user scrolls to the bottom. After I add the data to the adapter and call notifyDataSetChanged though, the ListView goes back up to the top. Ideally, I would like to retain the position in the ListView. Any thoughts on how I should go about doing this?

推荐答案

这会是您想要的吗?

// save index and top position
int index = mList.getFirstVisiblePosition();
View v = mList.getChildAt(0);
int top = (v == null) ? 0 : v.getTop();

// notify dataset changed or re-assign adapter here

// restore the position of listview
mList.setSelectionFromTop(index, top);

编辑 28/09/2017:

EDIT 28/09/2017:

API 自 2015 年以来发生了很大变化.它是相似的，但现在是:

The API has changed quite a bit since 2015. It is similar, but now it would be:

// save index and top position
int index = mList.FirstVisiblePosition; //This changed
View v = mList.getChildAt(0);
int top = (v == null) ? 0 : v.Top; //this changed

// notify dataset changed or re-assign adapter here

// restore the position of listview
mList.setSelectionFromTop(index, top);

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