我有一个列表视图即得到进一步意见，要求补充说，这是由一个BaseAdapter维护。 我怎样才能保持在更新后滚动位置？
我知道这已经被问了几次，但每次，相同的解决方案已经被提出来的，我都试过了，这是调用adapter.notifyDataSetChanged(); 更新包含列表内容的ArrayList中后。
我怎么能保证滚动位置保持？
Answer 1:
实施OnScrollListener您的活动类，然后使用下面的代码：
int currentFirstVisibleItem, currentVisibleItemCount, currentTotalItemCount;
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
this.currentFirstVisibleItem = firstVisibleItem;
this.currentVisibleItemCount = visibleItemCount;
this.currentTotalItemCount = totalItemCount;
}
public void onScrollStateChanged(AbsListView view, int scrollState) {
this.currentScrollState = scrollState;
this.isScrollCompleted();
}
private void isScrollCompleted() {
if (currentFirstVisibleItem + currentVisibleItemCount >= currentTotalItemCount) {
if (this.currentVisibleItemCount > 0
&& this.currentScrollState == SCROLL_STATE_IDLE) {
//Do your work
}
}
}
如果您使用AsyncTask用于更新数据，那么您可以在您的以下PostExecute()以保持滚动位置：
list.setAdapter(adapter);
list.setSelectionFromTop(currentFirstVisibleItem, 0);
我希望这有帮助。
Answer 2:
我采取的办法是调用ListView.setSelection(position)滚动到期望的position在更新之后。
这取决于你是从调用它，您可能需要调用requestFocusFromTouch调用之前setSelection ，以确保得到适当位置的项目。
Answer 3:
这个代码将会帮助你....
// get position of listview
int index = listView.getFirstVisiblePosition();
View v = listView.getChildAt(0);
int top = (v == null) ? 0 : v.getTop();
// notify dataset changed or re-assign adapter here
//re-assign the position of listview after setting the adapter again
listView.setSelectionFromTop(index, top);
干杯:)
Answer 4:
你可以试试这个：
//Get the top position from the first visible element
int fVisible = list.getFirstVisiblePosition();
View vFirst = list.getChildAt(0);
int pos = 0;
if (vFirst != null) pos = vFirst.getTop();
//Restore the position
list.setSelectionFromTop(fVisible, pos);
Answer 5:
你可以如下做到。 如果你想与滚动加载更多的数据，底部也将有一些变化。
int currentFirstVisibleItem, currentScrollState;
int countChange = 0;
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
Log.d("Scroll", "Scrolling");
this.currentFirstVisibleItem = firstVisibleItem;
countChange = 0;//during touching you can decide not to refresh by scroll
}
public void onScrollStateChanged(AbsListView view, int scrollState) {
Log.d("Scroll", "Changed");
this.currentScrollState = scrollState;
if (scrollState == SCROLL_STATE_TOUCH_SCROLL) {
countChange = 0;
}
if (++countChange > 1) {
//scroll to top and release touch change=2. Simple scroll and release touch change=1
this.isScrollCompleted();
countChange = 0;
}
}
private void isScrollCompleted() {
Log.d("Load", "Reload");
if (currentFirstVisibleItem == 0) {
//Your loading go here
}
}
文章来源: Android ListView - scrolls back to top on update
