我已经阅读了很多关于如何在RecyclerView
设备旋转时保留当前滚动位置的建议。我现在发现,当我使用时com.android.support:recyclerview-v7:23.0.+
,当前位置实际上是保存在savedInstanceState
. 它似乎也被恢复了,但它只是“稍微正确地”恢复了。
我正在经历这个:我以纵向模式滚动到列表的底部,然后切换到横向。当前位置已正确恢复(当然,有些项目不可见 - 我可以继续滚动)!
没有任何进一步的滚动,我旋转回纵向,恢复的位置比我实际认为的位置高出几项。列表不再滚动到底部。
我的问题是:我还能做些什么来实际存储和恢复正确的滚动位置?
这是的布局RecyclerView
:
<android.support.v4.widget.SwipeRefreshLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/swipeLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="...">
<android.support.v7.widget.RecyclerView
android:id="@+id/itemsView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbars="vertical" />
</android.support.v4.widget.SwipeRefreshLayout>
这是单个项目的缩短布局:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingTop="8dp"
android:paddingBottom="8dp"
android:paddingLeft="12dp"
android:paddingRight="12dp">
<!-- This linear layout aligns type indicator to the left and text content to the right -->
<LinearLayout
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content">
...
</LinearLayout>
</LinearLayout>
承载 的片段RecyclerView
具有以下代码:
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
View v = inflater.inflate(R.layout.calendar_fragment, container, false);
ButterKnife.bind(this, v);
mSwipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
@Override
public void onRefresh() {
...
}
});
if (mLayoutManager == null)
{
mLayoutManager = new LinearLayoutManager(getActivity());
mLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
}
// Get cached information or access storage
if (savedInstanceState != null)
{
// Initialize the area and the adapter from the saved state
mArea = savedInstanceState.getParcelable("AREA");
Entry[] entries = (Entry[])savedInstanceState.getParcelableArray("ITEMS");
mDataAdapter = new MyAdapter(this, mArea, entries);
}
else
{
// Initialize the area and the adapter form scratch
mArea = getAreaByPreference();
mDataAdapter = new MyAdapter(this, mArea);
}
// Initialize the RecyclerView
mItemsView.setHasFixedSize(true);
mItemsView.setAdapter(mDataAdapter);
mItemsView.setLayoutManager(mLayoutManager);
return v;
}