Question

当您单击复选框时，应用程序主题更改不起作用，并且不会重新启动。我尝试使用方法doRestart（）重新启动并重新创建。但是它最初几次都起作用。那么什么都不起作用

这是我的主要活动

public abstract class Navigation extends AppCompatActivity  {

private static String TAG;
private DrawerLayout drawer;
private ActionBarDrawerToggle t;
private NavigationView nv;
private static Context context;
private int theme = R.style.AppTheme;
private static String THEME_TAG = "Navigation.THEME";

@LayoutRes
protected int getLayoutResId() {
    return R.layout.activity_fragment;
}


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    int theme_tmp = savedInstanceState== null? theme : savedInstanceState.getInt(THEME_TAG, theme);
    setTheme(theme_tmp);
    setContentView(getLayoutResId());

   SharedPreferences pref = PreferenceManager.getDefaultSharedPreferences(this);
    Boolean themeB = pref.getBoolean("theme", true);

    if (themeB){
        theme = R.style.AppTheme;
    } else {
        theme = R.style.Light;
    }
    context = getApplicationContext();
    pref.registerOnSharedPreferenceChangeListener((sharedPreferences, key) -> {
        if ("theme".equals(key)){

            setTheme(theme);
            recreate();
            //doRestart(context);
        }

    });

    drawer = findViewById(R.id.drawer_layout);
    t = new ActionBarDrawerToggle(this, drawer, R.string.Open, R.string.Close);
    drawer.addDrawerListener(t);
    t.syncState();

    getSupportActionBar().setDisplayHomeAsUpEnabled(true);

    nv = findViewById(R.id.nav_view);
    nv.setNavigationItemSelectedListener(item -> {
        int id = item.getItemId();
        switch (id) {
            case R.id.account:

                openFragment("account");
                drawer.closeDrawers();
                break;
            /*case R.id.recipes:
                openFragment("R.id.recipes");
                break;*/
            case R.id.settings:
                openFragment("settings");
                drawer.closeDrawers();
                break;
            default:
                return true;
        }
        return false;
    });

}

public void openFragment(String frag) {
    FragmentManager fm = getSupportFragmentManager();
    Fragment fragment = fm.findFragmentByTag(frag);

    if (fragment == null) {
        switch (frag) {
            case "account":
                fragment = new AccountFragment();
                break;
           /* case "R.id.recipes":
                break;*/
            case "settings":
                fragment = new SettingsFragment();
                break;
            }
        fm.beginTransaction()
                .replace(R.id.container_fragments, fragment, frag)
                .commit();

    }
}
public void doRestart(Context c) {
    try {
        //check if the context is given
        if (c != null) {
            //fetch the packagemanager so we can get the default launch activity
            // (you can replace this intent with any other activity if you want
            PackageManager pm = c.getPackageManager();
            //check if we got the PackageManager
            if (pm != null) {
                //create the intent with the default start activity for your application
                Intent mStartActivity = pm.getLaunchIntentForPackage(
                        c.getPackageName()
                );
                if (mStartActivity != null) {
                    mStartActivity.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                    //create a pending intent so the application is restarted after System.exit(0) was called.
                    // We use an AlarmManager to call this intent in 100ms
                    int mPendingIntentId = 223344;
                    PendingIntent mPendingIntent = PendingIntent
                            .getActivity(c, mPendingIntentId, mStartActivity,
                                    PendingIntent.FLAG_CANCEL_CURRENT|PendingIntent.FLAG_UPDATE_CURRENT);
                    AlarmManager mgr = (AlarmManager) c.getSystemService(Context.ALARM_SERVICE);
                    mgr.set(AlarmManager.RTC, System.currentTimeMillis() + 100, mPendingIntent);
                    startActivity(getIntent());
                   finish();


                } else {
                    System.out.println("Was not able to restart application, mStartActivity null");
                }
            } else {
                System.out.println("Was not able to restart application, PM null");
            }
        } else {
            System.out.println("Was not able to restart application, Context null");
        }
    } catch (Exception ex) {
        System.out.println("Was not able to restart application");
    }
}

@Override
protected void onSaveInstanceState(Bundle outState) {
    outState.putSerializable(THEME_TAG, theme);
    super.onSaveInstanceState(outState);
    }
}

setttings.xml

<PreferenceScreen
xmlns:android="http://schemas.android.com/apk/res/android">
<PreferenceCategory
    android:title="@string/personalization">
    <CheckBoxPreference
        android:key="@string/theme"
        android:title="@string/checkbox_dark_theme">
    </CheckBoxPreference>
</PreferenceCategory>
<ListPreference
    android:entries="@array/sizes"
    android:entryValues="@array/sizes_values"
    android:key="list_sizes"
    android:summary="@string/font_size_summary"
    android:title="@string/font_size">
</ListPreference>

和此settengfFragment

公共类SettingsFragment扩展了PreferenceFragmentCompat {

private int theme = R.style.AppTheme;
@Override
public void onCreatePreferences(Bundle bundle, String s) {
    addPreferencesFromResource(R.xml.settings);
    }

}

如何使用首选项复选框正确更改android应用程序主题？

0 个答案: