当多个加载程序与加载程序管理器一起使用时，android无法在方向更改时保持正确的加载程序状态

Question

I am using 4 loaders in my application to load data into a listview. When I change the orientation the loader manager always tries to load the first loader. To solve this issue I am restarting the loader in "onResume" of the application. Now the listview is populated with the data but the position of the list before orientation change in not maintained. Is there any way to maintain the loader state on orientation change ?

Answer 1

If you can't prevent the re-loading of the list, you can at least restore the position:

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    if (null != savedInstanceState) {
        mViewPosition = savedInstanceState.getInt(KEY_LIST_CUR_POS);
        mViewOffset = savedInstanceState.getInt(KEY_LIST_VIEW_OFFSET);
    } 
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.status_list, container, false);
    return(view);
}

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);

    // Restore list position.
    getListView().setSelectionFromTop(mViewPosition, mViewOffset);
}

@Override
public void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);

    // Save current view in list.
    outState.putInt(KEY_LIST_CUR_POS, mViewPosition);
    outState.putInt(KEY_LIST_VIEW_OFFSET, mViewOffset);
}

@Override
public void onPause() {
    super.onPause();

    mViewPosition = getListView().getFirstVisiblePosition();
    View v = getListView().getChildAt(0);
    mViewOffset = (v == null) ? 0 : v.getTop();
}