我不知道如何将 bean 类的对象保存在 onSavedInstance 中,并通过检查 savedInstanceState 为 null 在 onCreate 中检索它。
到目前为止,我一直在尝试此代码,但无法保存/检索值:-
public class BookActivity extends Activity{
private ArrayList<Bitmap> bitmaps = null;
private ArrayList<Book> bookData = null; //Book is the bean class
private TextView bookTitle = null;
private ArrayList<Feature> bookIds = null; // Another bean class
@Override
public void onSaveInstanceState(Bundle savedInstanceState) {
savedInstanceState.putSerializable("bookThumb", bookData);
savedInstanceState.putSerializable("bookBitmaps", bitmaps);
savedInstanceState.putSerializable("featureBook", bookIds);
super.onSaveInstanceState(savedInstanceState);
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.penguin_main);
if(savedInstanceState!=null){
bookData = (ArrayList<String>) savedInstanceState.getSerializable("bookThumb");
bookData = (ArrayList<String>) savedInstanceState.getSerializable("bookThumb");
bookData = (ArrayList<String>) savedInstanceState.getSerializable("bookThumb");
}
else{
Toast msg = Toast.makeText(getApplicationContext(), "Values Not Restored!!!", Toast.LENGTH_LONG);
msg.setGravity(Gravity.CENTER, msg.getXOffset() / 2, msg.getYOffset() / 2);
msg.show();
}
}
}
我应该怎么做才能保存我的位图和 Book 的对象,以便它不会在方向更改时生成类的新实例?