我正在尝试编写一个单例类来监督涉及共享首选项的所有操作.
我希望能够使用此类来编写给定类型的首选项,例如：
stg_full_screen: true // as boolean
这是我到目前为止所做的：
import android.app.Activity;
import android.content.Context;
import android.content.SharedPreferences;
public class SharedPrefManager extends Activity {
// Globals
private int GENERAL = 1000;
private int SETTINGS = 2000;
private int TEMP_STORE = 3000;
private String PREF_GENERAL = "com.example.general";
private String PREF_SETTINGS = "com.example.settings";
private String PREF_TEMP_STORE = "com.example.temp_store";
private SharedPreferences general;
private SharedPreferences settings;
private SharedPreferences tempStore;
private SharedPreferences.Editor general_editor;
private SharedPreferences.Editor settings_editor;
private SharedPreferences.Editor temp_store_editor;
// Instantiate singleton object
private static SharedPrefManager ourInstance = new SharedPrefManager();
public static SharedPrefManager getInstance() { return ourInstance; }
private SharedPrefManager() {
// Get handle on all preference files
general = getSharedPreferences(PREF_GENERAL,Context.MODE_PRIVATE);
settings = getSharedPreferences(PREF_SETTINGS,Context.MODE_PRIVATE);
tempStore = getSharedPreferences(PREF_TEMP_STORE,Context.MODE_PRIVATE);
// provision editors for all preference files
general_editor = general.edit();
settings_editor = settings.edit();
temp_store_editor = tempStore.edit();
}
private String read_prefs (String pref_name) {
// this method reads a preference and returns it
// ideally,i would want to be able to return appropriate types by request
// e.g boolean,string
return null;
}
private void write_prefs (String pref_name,String pref_val) {
// this method would take a preference and write the appropriate type to prefs
}
// this method determines where to put a preference by checking the name of the key
// this works because i use the following naming conventions
// stg_name for settings,tmp_name for all that goes into tempStore
private String resolve_pref_category (String path) {
if (path.startsWith("stn")) return PREF_SETTINGS;
else if (path.startsWith("tmp")) return PREF_TEMP_STORE;
else return PREF_GENERAL;
}
}
我的问题是：
>这是明智的做法吗？
>我如何有效地确定偏好的类型？
谢谢
解决方法
通常,我使用这样的东西：
没有静态上下文引用,每个属性的静态getter / setter,在需要时,您可以为某些属性添加内存缓存值,以便从内存中更快地获取它,而不是从SharedPreferences中读取.明确的api.
public class SharedPreferencesManager {
private static final String APP_SETTINGS = "APP_SETTINGS";
// properties
private static final String SOME_STRING_VALUE = "SOME_STRING_VALUE";
// other properties...
private SharedPreferencesManager() {}
private static SharedPreferences getSharedPreferences(Context context) {
return context.getSharedPreferences(APP_SETTINGS,Context.MODE_PRIVATE);
}
public static String getSomeStringValue(Context context) {
return getSharedPreferences(context).getString(SOME_STRING_VALUE,null);
}
public static void setSomeStringValue(Context context,String newValue) {
final SharedPreferences.Editor editor = getSharedPreferences(context).edit();
editor.putString(SOME_STRING_VALUE,newValue);
editor.commit();
}
// other getters/setters
}
