使用共享首选项保存android主题

Question

你好，我正在尝试保存一个共享首选项的主题。当用户点击某个主题的按钮时，我希望该主题被设置为默认并保存，所以当他们重新打开应用程序时，它仍然是那个新主题。

/** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        Utils.onActivityCreateSetTheme(this);
        setContentView(R.layout.activity_main);

        findViewById(R.id.button1).setOnClickListener(this);
        findViewById(R.id.button2).setOnClickListener(this);
        findViewById(R.id.button3).setOnClickListener(this);


    }
    @Override
    public void onClick(View v)
    {
        switch (v.getId())
        {
            case R.id.button1:
                Utils.changeToTheme(this, Utils.THEME_DEFAULT);
                break;
            case R.id.button2:
                Utils.changeToTheme(this, Utils.THEME_WHITE);
                break;
            case R.id.button3:
                Utils.changeToTheme(this, Utils.THEME_BLUE);
                break;
        }
    }
}

public class Utils{
private static int sTheme;
public final static int THEME_DEFAULT = 0;
public final static int THEME_WHITE = 1;
public final static int THEME_BLUE = 2;
/**
 * Set the theme of the Activity, and restart it by creating a new Activity of the same type.
 */
public static void changeToTheme(Activity activity, int theme)
{
    sTheme = theme;
    activity.finish();
    activity.startActivity(new Intent(activity, activity.getClass()));
}
/** Set the theme of the activity, according to the configuration.
 * @param activity*/
public static void onActivityCreateSetTheme(MainActivity activity)
{
    switch (sTheme)
    {
        default:
        case THEME_DEFAULT:
            activity.setTheme(R.style.AppTheme);
            break;
        case THEME_WHITE:
            activity.setTheme(R.style.MyTheme);
            break;
        case THEME_BLUE:
            activity.setTheme(R.style.My2Theme);
            break;

Answer 1

在这里你可以找到关于SharedPreferences的教程，基本上你应该存储所选主题的编号，当应用程序启动时，检查哪个主题存储在SharedPreferences上。在检索到值之后，您可以在全局范围内“存储”它，以检查其他活动的主题编号（这样，您不必每次都在应用程序启动时检查SharedPreferences）。

更新0

下面是一个处理SharedPreference的类：

public class SharedPreferencesManager {
/**
 * SharedPreferences to store the settings. This way, they'll be available next time the user starts the app
 */
private SharedPreferences sPreferences;
/**
 * Editor to make changes on sharedPreferences
 */
private SharedPreferences.Editor sEditor;

/**
 * The class itself
 */
private Context context;

public SharedPreferencesManager(Context context){
    this.context = context;
    sPreferences = PreferenceManager.getDefaultSharedPreferences(context);
}

private SharedPreferences.Editor getEditor(){
    return sPreferences.edit();
}

/**
 * Store a boolean value in sharedPreferences
 * @param tag identifies the value
 * @param value the value itself
 */

public void storeBoolean(String tag, boolean value){
    sEditor = getEditor();
    sEditor.putBoolean(tag,value);
    sEditor.commit();
}
/**
 * Store a string in sharedPreferences
 * @param tag identifies the value
 * @param str the string itself
 */

public void storeString(String tag, String str){
    sEditor = getEditor();
    sEditor.putString(tag, str);
    sEditor.commit();
}

/**
 *
 * @param tag identifies the value
 * @param defValue default value
 * @return the stored or default value
 */

public boolean retrieveBoolean(String tag, boolean defValue){
    return sPreferences.getBoolean(tag,defValue);

}

/**
 *
 * @param tag identifies the string
 * @param defStr default string
 * @return the stored or default string
 */

public String retrieveString(String tag, String defStr){
    return sPreferences.getString(tag, defStr);
}

/**
 *
 * @param tag identifies the value
 * @param defValue default value
 * @return the stored or default value
 */
public int retrieveInt(String tag, int defValue){
    return sPreferences.getInt(tag, defValue);
}

/**
 *
 * @param tag identifies the value
 * @param defValue the value itself
 */
public void storeInt(String tag, int defValue){
    sEditor = getEditor();
    sEditor.putInt(tag, defValue);
    sEditor.commit();
}
//Incorrect Bracket Closing Removal.

public final static int THEME_DEFAULT = 0;
public final static int THEME_WHITE = 1;
public final static int THEME_BLUE = 2;

new SharedPreferencesManager(getApplicationContext()).storeInt("theme", THEME_WHITE);

Utils.changeToTheme(this, new SharedPreferencesManager(this).retrieveInt("theme", THEME_WHITE));

请记住，当您要从SharedPreferences中检索值时，必须传递默认值，因此如果没有存储与标记“theme”相关的内容，它将返回默认值。

我没有测试这段代码，也许你得稍微了解一下。