Question

在我的小部件中使用共享首选项时遇到了一些问题。我一直在我的共享首选项上获得此调试消息，但是id foes并不是一个错误。

unable to unlink'/data/data/com.MyApps.WeatherViewer/shared_prefs/USER_PREFERENCE_WEATHER.xml.bak': No such file or directory (errno=2)

当我尝试访问它时，存储在我的共享首选项中的值返回null可能是什么问题。

2。）是否可以从创建它们的活动中立即从共享首选项中检索值？..

这是我创建SharedPreference的代码：

     public static final String USER_PREFERENCE_MODE = "USER_PREFERENCES_WEATHER";
        public static final String PREF_CITY_ENTRY = "PREF_CITY_ENTRY";
        public static final String PREF_TOGGLE_CELSIUS = "PREF_TOGGLE_CELSIUS";
        public static final String PREF_FREQ_UPDATE = "PREF_FREQ_UPDATE";

        SharedPreferences prefs;

        public void onCreate(Bundle icicle) {
            super.onCreate(icicle);

                  setContentView(R.layout.weather_view_configuration);


            cityText =(EditText)findViewById(R.id.editCity_id);
            chk_celsius = (CheckBox) findViewById(R.id.celsius_toggle_id);
            save =(Button)findViewById(R.id.SaveButton);
            update =(Spinner)findViewById(R.id.spinner_update_id);

            cityText.setOnClickListener(this);
            save.setOnClickListener(this);

            prefs = this.getSharedPreferences(USER_PREFERENCE_MODE,0);
            updateUIFromPreferences();
       }

        @Override
        public void onClick(View v) {
            final Context context = WeatherForecastConfigure.this;
            int selection = v.getId();

            switch(selection){
            case R.id.SaveButton:
                   savePreferences();

   prefs = getSharedPreferences(USER_PREFERENCE_MODE,0);
 RemoteViews views = new RemoteViews(context.getPackageName(),R.layout.weather_appwidget ); 
    String text = prefs.getString(WeatherForecastConfigure.PREF_CITY_ENTRY,null);    
                 views.setTextViewText(R.id.weather_city_id, text);
                 AppWidgetManager widgetManager = AppWidgetManager.getInstance(context);
                                  widgetManager.updateAppWidget(appWidgetID, views);

            }
        }

        private void updateUIFromPreferences() {
            String cityEntry = prefs.getString(PREF_CITY_ENTRY, cityText.getText().toString());
            boolean celsiusToggle = prefs.getBoolean(PREF_TOGGLE_CELSIUS, false);
            int updateIndex = prefs.getInt(PREF_FREQ_UPDATE, 0);

            cityText.setText(cityEntry);
            update.setSelection(updateIndex);
            chk_celsius.setChecked(celsiusToggle);
        }


        private void savePreferences() {
            prefs = this.getSharedPreferences(USER_PREFERENCE_MODE,0);

            int updateIndex = update.getSelectedItemPosition();
            boolean celsiusToggle =  chk_celsius.isChecked();
            String city = cityText.getText().toString();


            Editor editor = prefs.edit();
            editor.putString(PREF_CITY_ENTRY, city);
            editor.putBoolean(PREF_TOGGLE_CELSIUS, celsiusToggle);
            editor.putInt( PREF_FREQ_UPDATE, updateIndex);
            editor.commit();
        }

提前致谢

这是我的服务代码：

public class weatherForecast extends Service  {

     public static final String UPDATE = "update";
     int appWidgetID = AppWidgetManager.INVALID_APPWIDGET_ID;

     String city;
     Boolean chk_celsius;
     SharedPreferences prefs;

    @Override
    public IBinder onBind(Intent arg0) {
        // TODO Auto-generated method stub
        return null;
    }

    public void onCreate(){
        Log.d(TAG, "onCreate");

prefs = getApplicationContext().getSharedPreferences(WeatherForecastConfigure.USER_PREFERENCE_MODE, 0);

 city = prefs.getString(WeatherForecastConfigure.PREF_CITY_ENTRY,"");
 chk_celsius = prefs.getBoolean(WeatherForecastConfigure.PREF_TOGGLE_CELSIUS, false);

        Log.i(TAG, "city is " + city);
    }

    public void onStart(Intent intent, int startId){
        URL url;
        Log.d(TAG,"onStart");


     Bundle extra = intent.getExtras();
    if(extra != null){
  appWidgetID = extra.getInt(AppWidgetManager.EXTRA_APPWIDGET_ID, AppWidgetManager.INVALID_APPWIDGET_ID);

    Log.v("WIDGET_TAG_ID", "appWidgetId = " + appWidgetID);
           }

    /* prefs = this.getSharedPreferences("prefs", 0);
  city = prefs.getString(WeatherForecastConfigure.PREF_CITY_ENTRY + appWidgetID,"");
  chk_celsius = prefs.getBoolean(WeatherForecastConfigure.PREF_TOGGLE_CELSIUS, false);
            Log.i(TAG, "city is " + city);*/


       RemoteViews updateViews = buildUpdate(this);
       ComponentName thisWidget = new ComponentName(this, WeatherWidgetProvider.class);
       AppWidgetManager widgetManager = AppWidgetManager.getInstance(this);
       widgetManager.updateAppWidget(thisWidget, updateViews);


        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
            super.onStart(intent, startId);
        }

   public RemoteViews buildUpdate(Context context) {
   GoogleWeatherHandler gwh = new GoogleWeatherHandler();
   WeatherSet weather = gwh.getWeatherSet();
   RemoteViews remote = RemoteViews(context.getPackageName(), R.layout.weather_appwidget );
   AppWidgetManager widgetManager = AppWidgetManager.getInstance(this);
  remote.setTextViewText(R.id.editCity_id,weather.getCondition().getCity().toString());
remote.setTextViewText(R.id.weather_condition_id,weather.getCondition().getCondition().toString());
remote.setTextViewText(R.id.weather_tempreture_id,weather.getCondition().getTempCelcius().toString());

widgetManager.updateAppWidget(appWidgetID, views);
   return views;
  }
}

Answer 1

由于缺乏更好的术语，您的代码看起来像是一个“循环问题”。

例如，您致电

updateUIFromPreferences();

哪个

String cityEntry = prefs.getString(PREF_CITY_ENTRY, cityText.getText().toString());
cityText.setText(cityEntry);

然后你的保存按钮

String city = cityText.getText().toString();
editor.putString(PREF_CITY_ENTRY, city);

如果您没有将cityText设置为实际值，则只需将空值传递回首选项即可。没有整个活动，我无法确定，但问题来自于它的外观。

共享首选项上不存在任何文件或目录

1 个答案: