java - SharedPreferences 如何与 UpdateUI 配合？

Question

我是开发 Android 应用程序的菜鸟。我想问一下。我的 PreferenceActivity 如何希望在不返回 MainActivity 并再次转到 PreferenceActivity 的情况下更新。在此，我提供了一些功能来更改 PreferenceActivity 的主题。这是我的 PreferenceActivity:

公共(public)类SettingsPreference扩展了PreferenceActivity{

SwitchPreference themeSwitch;
String myPref = "preferences";
SharedPreferences.Editor editor;
String summary;
int theme;

@Override
public void onCreate(Bundle savedInstanceState)
{
    // TODO: Implement this method
    final SharedPreferences.Editor editor = getSharedPreferences(myPref, MODE_PRIVATE).edit();

    final SharedPreferences prefs = getSharedPreferences(myPref, MODE_PRIVATE); 
    final String summary = prefs.getString("stringSummary", "Default theme");
    final int theme = prefs.getInt("intTheme", (android.R.style.Theme_DeviceDefault_Light));   

    setTheme(theme);

    super.onCreate(savedInstanceState);
    addPreferencesFromResource(R.xml.settings_preference);

    themeSwitch = (SwitchPreference) findPreference("switchTheme");
    themeSwitch.setSummary(summary);

    if (themeSwitch != null) {
        themeSwitch.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
                @Override
                public boolean onPreferenceChange(Preference arg0, Object isOnObject) {
                    boolean isThemeOn = (Boolean) isOnObject;
                    if (isThemeOn) {
                        Toast.makeText(SettingsPreference.this, "Theme Dark ON", Toast.LENGTH_SHORT).show();
                        editor.putString("stringSummary", "Theme Dark ON");
                        editor.putInt("intTheme", (android.R.style.Theme_DeviceDefault));
                        editor.apply();
                        themeSwitch.setSummary(summary);

                    } else {
                        Toast.makeText(SettingsPreference.this, "Theme Dark OFF", Toast.LENGTH_SHORT).show();
                        editor.putString("stringSummary", "Theme Dark OFF");
                        editor.putInt("intTheme", (android.R.style.Theme_DeviceDefault_Light));
                        editor.apply();
                        themeSwitch.setSummary(summary);

                    }
                    return true;
                }
            });
    }
}

}

Answer 1

如果您更改了 Activity 布局，则只需重新启动它即可。尝试将其添加到 onPreferenceChange() 的末尾。

如果您使用的是 API11+，请调用 Activity。

this.recreate();

否则，我们只需完成该 Activity 并以相同的 Intent 重新开始它即可。

Intent intent = getIntent();
finish();
startActivity(intent);