Android的保存和恢复CursorAdapter的国家名单 [英] Android Save and Restore List State with CursorAdapter
问题描述
我有一个由CursorAdapter的填充片段的列表视图。
I have a list view in a fragment that is populated by a CursorAdapter.
在设备旋转我要保存列表的状态，则无需进行其它调用的SQLite数据库恢复。
When the device rotates I want to save the state of the list, then restore it without having to make another call to the SQLite DB.
我如何做到这一点？
我不使用ContentProvider的或任何CursorLoaders。
I'm not using a ContentProvider or any CursorLoaders.
推荐答案
您可以挽救你的光标中的方法<一个href=\"http://developer.android.com/reference/android/app/Activity.html#onRetainNonConfigurationInstance%28%29\"相对=nofollow> onRetainNonConfigurationInstance（）您的活动或使用保存光标数据片段，并调用<一个href=\"http://developer.android.com/reference/android/app/Fragment.html#setRetainInstance%28boolean%29\"在相对=nofollow> setReatinInstance（）片段的的onCreate（）方法。
You could save your Cursor in the method onRetainNonConfigurationInstance() of your Activity or use a data fragment that holds the Cursor and call setReatinInstance() within the fragment's onCreate() method.
您然后必须重新创建的CursorAdapter 的的onCreate（）方法中。
You then have to recreate the CursorAdapter within the onCreate() method.
最后，你必须通过调用<一来存储你的的ListView 的当前可见的最上面的项目href=\"https://developer.android.com/reference/android/widget/AdapterView.html#getFirstVisiblePosition%28%29\"相对=nofollow> getFirstVisiblePosition（）在的ListView 。这个方法返回，你可以在你的活动的捆绑在的onSaveInstanceState（）方法保存一个int值。
Finally you have to store the currently visible topmost item of your ListView by calling getFirstVisiblePosition() on your ListView. This method returns an int value which you can store in a Bundle within the onSaveInstanceState() method of your Activity.
您使用了的onCreate（）方法该值（它传给了的onCreate包的一部分（））。并且适配器已被设置后，你可以调用[setSelectionFromTop（yourValue，0）]（的https://developer.android.com/reference/android/widget/ListView.html#setSelectionFromTop(int, INT））。
You use this value in the onCreate() method (it's part of the bundle passed to onCreate()). And after the adapter has been set, you call [setSelectionFromTop(yourValue, 0)](https://developer.android.com/reference/android/widget/ListView.html#setSelectionFromTop(int, int)).
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