Question

我试图用片段的onSaveInstanceState（）来保存变量的状态。我尝试保存的变量是在我的程序中的另一个类中创建的，但它总是被读为0（初始值）。我知道我正在增加变量值。如何获得变量的实际值？这是我的代码：

public class ObjectivesActivity extends Fragment {
//Variables
ObjectivesLogic objectivesLogic = new ObjectivesLogic();

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    // retain this fragment
    System.out.println("savedInstanceState: " + savedInstanceState);
    if (savedInstanceState != null) {
        // Restore last state for checked position.
    }
}

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

@Override
public void onStart() {
    super.onStart();
    if (objectivesLogic.getCount()>0){
        objectivesLogic.restoreFragment();
    }
}

@Override
public void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    int save = objectivesLogic.getCount();
    System.out.println("save: "+save);
    outState.putInt("Count",save);
}


}

这就是我创建变量的地方：

public class ObjectivesLogic extends AppCompatActivity {
//Variables
int count = 0;
View savedLinearLayoutView = null;
Context savedContext = null;
public void addObjective(Context context, View linearLayoutView) {
    savedContext = context;
    savedLinearLayoutView = linearLayoutView;
    if (count < 8) {
        EditText editText = new EditText(context);
        LinearLayout linearLayoutObjectives = (LinearLayout) linearLayoutView;
        editText.setId(R.id.edit_text_);
        linearLayoutObjectives.addView(editText);
        count++;
    }
}
public void restoreFragment(){
    for(int i=0; i<count;i++){
        EditText editText = new EditText(savedContext);
        LinearLayout linearLayoutObjectives = (LinearLayout) savedLinearLayoutView;
        editText.setId(R.id.edit_text_);
        linearLayoutObjectives.addView(editText);
        count++;
    }
}
public int getCount() {
    return count;
}
}

getCount（）始终为0。谢谢你的帮助:)）

Answer 1

我在您的代码中看到的两个问题应该解决。

ObjectivesLogic类正在扩展Activity类，这看起来并不需要。此外，你永远不应该手动实例化一个扩展Activity的类，这应该由Android框架完成而不是你。
您只保存该变量：outState.putInt("Count",save);。我看不出任何关于恢复它的事情。

Answer 2

您在super.onSaveInstanceState(outState);

之前致电outState.putInt("Count",save);

@Override
public void onSaveInstanceState(Bundle outState) {
    int save = objectivesLogic.getCount();
    System.out.println("save: "+save);
    outState.putInt("Count",save);

    super.onSaveInstanceState(outState);

}

片段从另一个类获取变量值

2 个答案: