java - 如何结束 Activity 并重置 SharedPreferences.Editor 值？

Question

我正在使用 Android Studio 创建一个测验应用程序。我有一个 Activity 和寻呼机适配器，其中包含 3 个 fragment (问题)。当我回答所有问题时(我在下面编写的代码只检查第一个问题，只是为了不占用太多空间)并按下结束按钮，新 Activity 将打开并显示结果。但有时结果显示不正确。我怀疑我的 SharedPreferences.Editor 值在我开始测试 Activity 时不正确，所以我尝试在 Activity 启动后将其设置为 0。问题仍然存在。

可能是我在 fragment 中使用了错误的方法来发送结果(在本例中为 onStop()，但我也尝试过 onDetach、onDestroyView、onDestroy)。

我也尝试过将 editor.apply() 更改为 editor.commit() ，没有任何区别。

问题1.java

public class Question1 extends android.support.v4.app.Fragment {

    private CheckBox cb1;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceStance) {
        View v = inflater.inflate(R.layout.fragment_question1, null);
        return v;
    }

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


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

        cb1 = (CheckBox)getView().findViewById(R.id.checkBox1);

        final SharedPreferences app_preferences = PreferenceManager.getDefaultSharedPreferences(getActivity());
        SharedPreferences.Editor editor = app_preferences.edit();

        if (cb1.isChecked()) {
            editor.putInt("answer_value", 1);
        } else {
            editor.putInt("answer_value", 0);
        }
        editor.apply();
    }

}

测试.java

public class testActivity extends FragmentActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_pager_adapter);
        initialisePaging();
        defaultValue();
    }

    private void defaultValue() {
        final SharedPreferences app_preferences = PreferenceManager.getDefaultSharedPreferences(this);
        SharedPreferences.Editor editor = app_preferences.edit();

        editor.putInt("answer_value", 0);
        editor.apply();
    }

    public void goResult(View view){
        Intent intent = new Intent(testActivity.this, Result.class);
        startActivity(intent);
    }


    private  void initialisePaging() {
        List<Fragment> fragments = new Vector<Fragment>();
        fragments.add(Fragment.instantiate(this,Qestion1.class.getName()));
        fragments.add(Fragment.instantiate(this,Qestion2.class.getName()));
        fragments.add(Fragment.instantiate(this,Question3.class.getName()));
        PagerAdapter mPagerAdapter = new PagerAdapter(this.getSupportFragmentManager(), fragments);

        Collections.shuffle(fragments, new Random(System.nanoTime()));

        ViewPager pager = (ViewPager) findViewById(R.id.viewpager);
        pager.setAdapter(mPagerAdapter);
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu_greitas_testas, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;}
        return super.onOptionsItemSelected(item);
    }

}

结果.java

public class Result extends ActionBarActivity {

    TextView win_lose;
    int Ats1, Ats2, Ats3;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getSupportActionBar().hide();
        setContentView(R.layout.activity_result);
        calculateResult();
    }


    private void calculateResult() {
        win_lose = (TextView)findViewById(R.id.textView9);          

        final SharedPreferences app_preferences = PreferenceManager.getDefaultSharedPreferences(this);

        int Ans1 = app_preferences.getInt("answer_value", 0);

        if ( Ans1 == 1 ){
            win_lose.setText("Win");
        } else {
            win_lose.setText("Lose");
        }    

    }

    public void onBackPressed(){
        Intent intent = new Intent(Result.this, mainActivity.class);
        startActivity(intent);
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu_result, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

PagerAdapter.java

public class PagerAdapter extends FragmentPagerAdapter {

    private List<Fragment> fragments;

    public PagerAdapter(FragmentManager fm, List<Fragment> fragments) {
        super(fm);
        this.fragments = fragments;
    }

    @Override
    public Fragment getItem(int arg0) {
        return this.fragments.get(arg0);
    }

    @Override
    public int getCount() {
        return this.fragments.size();
    }

    public void setFragments(List<Fragment> fragments) {
        this.fragments = fragments;
    }
}

Answer 1

如果我没看错，您将值保存为

editor.putInt("answer_value", 0);

但你正在阅读它

int Ans1 = app_preferences.getInt("atsakymo_vertė", 0);

保存键和读取键应该是一样的!