Android listView scroll 恢复滚动位置

private int mPosition;
private int lvChildTop;

@Override
public void onPause() {
// TODO Auto-generated method stub
super.onPause();

SharedPreferences mySharedPreferences = activity.getSharedPreferences(MY_PREFS, Activity.MODE_PRIVATE);
SharedPreferences.Editor edit = mySharedPreferences.edit();
edit.putInt("mPositionChildTop", lvChildTop);
edit.putInt("mPosition", mPosition);

edit.commit();
}

@Override
public void onResume() {
// TODO Auto-generated method stub
super.onResume();

SharedPreferences mySharedPreferences = activity.getSharedPreferences(MY_PREFS, Activity.MODE_PRIVATE); // MY_PREFES 是声明的字符串
lvChildTop = mySharedPreferences.getInt("mPositionChildTop", 0);
mPosition = mySharedPreferences.getInt("mPosition", 0);
listMessage.setSelectionFromTop(mPosition, lvChildTop); // listMessage 是listview ，
}

private OnScrollListener lvScrollListener = new OnScrollListener() {

@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
// TODO Auto-generated method stub
// 不滚动时保存当前滚动到的位置
if (scrollState == OnScrollListener.SCROLL_STATE_IDLE) {
mPosition = listMessage.getFirstVisiblePosition();
View v = listMessage.getChildAt(0);
lvChildTop = (v == null) ? 0 : v.getTop();
}
}

@Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
// TODO Auto-generated method stub

}
};