Question

在发布之前，我尝试阅读有关恢复应用状态的许多主题并尝试了但是它并没有解决我的问题。

我的班级是：

public class MainActivity extends ActionBarActivity
    implements NavigationDrawerFragment.NavigationDrawerCallbacks {

    private static boolean lv11 = true;

    @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    mNavigationDrawerFragment = (NavigationDrawerFragment)
            getSupportFragmentManager().findFragmentById(R.id.navigation_drawer);
    mTitle = getTitle();

    // Set up the drawer.
    mNavigationDrawerFragment.setUp(
            R.id.navigation_drawer,
            (DrawerLayout) findViewById(R.id.drawer_layout));
}

@Override
public void onNavigationDrawerItemSelected(int position) {
    // update the main content by replacing fragments
    FragmentManager fragmentManager = getSupportFragmentManager();
    if(position == 0)
    {
        fragmentManager.beginTransaction()
                .replace(R.id.container, PlaceholderFragment.newInstance(position + 1))
                .commit();
    }
    else if(position == 1)
    {
        fragmentManager.beginTransaction()
                .replace(R.id.container, PlaceProfile.newInstance(position + 1))
                .commit();
    }
    else if(position == 2)
    {
        fragmentManager.beginTransaction()
                .replace(R.id.container, PlaceLogBook.newInstance(position + 1))
                .commit();
    }
    else if(position == 3)
    {
        fragmentManager.beginTransaction()
                .replace(R.id.container, PlaceBeverages.newInstance(position + 1))
                .commit();
    }
}
 @Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if(resultCode == RESULT_OK) {
        boolean finInfo = data.getBooleanExtra("Done", false);
        System.out.println("OnActivityResult = " + finInfo);
        if (finInfo == true) {
            readIt.setBackgroundColor(R.drawable.abc_ab_bottom_solid_light_holo);
            if (readIt.getText() == info1.getText()) {
                lv11 = false;
            }
        }
    }
}
public void onSectionAttached(int number) {
    switch (number) {
        case 1:
            mTitle = getString(R.string.title_section1);
            break;
        case 2:
            mTitle = getString(R.string.title_section2);
            break;
        case 3:
            mTitle = getString(R.string.title_section3);
            break;
        case 4:
            mTitle = getString(R.string.title_section4);
            break;
    }
}

public void restoreActionBar() {
    ActionBar actionBar = getSupportActionBar();
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
    actionBar.setDisplayShowTitleEnabled(true);
    actionBar.setTitle(mTitle);
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    if (!mNavigationDrawerFragment.isDrawerOpen()) {
        // Only show items in the action bar relevant to this screen
        // if the drawer is not showing. Otherwise, let the drawer
        // decide what to show in the action bar.
        getMenuInflater().inflate(R.menu.main, menu);
        restoreActionBar();
        return true;
    }
    return super.onCreateOptionsMenu(menu);
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}

public static class PlaceholderFragment extends Fragment {
    /**
     * The fragment argument representing the section number for this
     * fragment.
     */
    private static final String ARG_SECTION_NUMBER = "section_number";

    /**
     * Returns a new instance of this fragment for the given section
     * number.
     */
    public static PlaceholderFragment newInstance(int sectionNumber) {
        PlaceholderFragment fragment = new PlaceholderFragment();
        Bundle args = new Bundle();
        args.putInt(ARG_SECTION_NUMBER, sectionNumber);
        fragment.setArguments(args);
        return fragment;
    }

    public PlaceholderFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_main, container, false);
        InitializeItem();            
        if(savedInstanceState != null) {
            Log.v("","on Creat View");
            lv11 =  savedInstanceState.getBoolean("Level1");
            if (lv11 == false) {
                info1.setBackgroundColor(R.drawable.abc_ab_bottom_solid_light_holo);
            }
        }
          //where i create my view ...
         return rootView;
       }

    @Override
    public void onSaveInstanceState(Bundle savedInstanceState) {

        Log.v("TAG", "In frag's on save instance state ");
        savedInstanceState.putBoolean("Level1",false);
        super.onSaveInstanceState(savedInstanceState);
    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        ((MainActivity) activity).onSectionAttached(
                getArguments().getInt(ARG_SECTION_NUMBER));
    }
}

所有工作正常但我的问题是使用onSaveInstantState（）方法。我使用Log.v进行检查，当我按下硬件上的最近按钮然后我就杀了它。之后当我再次运行应用程序时，我的SaveInstantstate是在我的情况下，我想通过check参数更改按钮颜色，将参数置于保存状态并将其恢复为onCreateView。

我想知道：

我的实施中出了什么问题以及为什么我无法调用恢复状态
如何以正确的方式实施

* 以上所有代码都在同一个类文件中

谢谢，对不起我的语法。

Answer 1

杀死你的应用程序之后，你所有的Bundles都被销毁了。 onSavedInstanceState（）用于保护应用程序的状态不被操作系统杀死。在您的情况下，您需要永久保存状态。 “SharedPreferences”非常适合。

片段中无法保存和恢复变量

1 个答案: