Question

我需要在用户更改首选项后更新片段中的两个textview。我已经找了很多类似的问题，但它不会帮助我。我甚至尝试每次更新所有应用程序，但我确定它不是最好的解决方案。将不胜感激任何帮助。

AppPreferenceActivity.java

public class AppPreferenceActivity extends PreferenceActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        getFragmentManager().beginTransaction().replace(android.R.id.content, new MyPreferenceFragment()).commit();

    }

    public static class MyPreferenceFragment extends PreferenceFragment
    {
        @Override
        public void onCreate(final Bundle savedInstanceState)
        {
            super.onCreate(savedInstanceState);
            addPreferencesFromResource(R.xml.pref);
        }
    }
}

WeatherFragment.java （我为了方便而剪了代码）

    public class WeatherFragment extends Fragment implements Constants {

    TextView currentTemperatureField;
    TextView pressureField;
    //...


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_weather, container, false);
        currentTemperatureField = (TextView)rootView.findViewById(R.id.current_temperature_field);
        pressureField = (TextView) rootView.findViewById(R.id.pressure_field);

        //...

        weatherAdapter = new WeatherAdapter(getContext(), weather);
        ListView listView = (ListView)rootView.findViewById(R.id.listView);
        listView.setAdapter(weatherAdapter);

        return rootView;
    }


    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        updateWeatherData(new CityPreference(getActivity()).getCity());

        sharedPrefs = PreferenceManager.getDefaultSharedPreferences(getActivity());
        tempPref = sharedPrefs.getString("tempPref", "Celsius");
        pressurePref = sharedPrefs.getString("pressurePref","mmHg");

        //...

    }

    private void renderWeather(JSONObject json){
        try {
            //...

            if(pressurePref.equals("mmHg")) {
                pressureField.setText(String.format("%.0f", (main.getDouble("pressure") / 1.333)) + " mmHg");
            }else{
                pressureField.setText(String.format("%.0f", main.getDouble("pressure")) + " hPa");
            }

            if(tempPref.equals("Celsius")) {
                currentTemperatureField.setText(String.format("%.1f", main.getDouble("temp")) + " ℃");
            }else{
                currentTemperatureField.setText(String.format("%.1f", (main.getDouble("temp")*1.8+32)) + " ℉");
            }

            //...

        }catch(Exception e){
            //...
        }
    }  

}

UPD 感谢@beeb。我已经使用了OnSharedPreferenceChangeListener（）：

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    //weatherFont = Typeface.createFromAsset(getActivity().getAssets(), "fonts/weather.ttf");
    updateWeatherData(new CityPreference(getActivity()).getCity());

    sharedPrefs = PreferenceManager.getDefaultSharedPreferences(getActivity());
    tempPref = sharedPrefs.getString("tempPref", "Celsius");
    pressurePref = sharedPrefs.getString("pressurePref","mmHg");

    SharedPreferences.OnSharedPreferenceChangeListener listener = new SharedPreferences.OnSharedPreferenceChangeListener() {
        public void onSharedPreferenceChanged(SharedPreferences prefs, String key) {
            Log.e("WeatherActivity: ","preferences have changed");
            //Implementation
        }
    };

    sharedPrefs.registerOnSharedPreferenceChangeListener(listener);
}

但我的问题仍然是＆＃34;实施＆＃34;。我不知道如何将新数据设置为片段的文本视图。

Answer 1

不要像这样传递Fragment，而是采用以下方法制作实例。

 MyPreferenceFragment myPreferenceFragment;
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        myPreferenceFragment = new MyPreferenceFragment()
        getFragmentManager().beginTransaction().replace(android.R.id.content, myPreferenceFragment).commit();

    }

然后在片段中创建一个方法来更新textView

publich void updateText(String text)
{
   textView.setText(text);
}

并在想要更新文本时调用此方法：

myPreferenceFragment.updateText(text);

Answer 2

在SharedPreferences.onSharedPreferenceChangeListener()。

中添加WeatherFragment

listener = new SharedPreferences.OnSharedPreferenceChangeListener() {
  public void onSharedPreferenceChanged(SharedPreferences prefs, String key) {
    // Implementation
  }
};

prefs.registerOnSharedPreferenceChangeListener(listener);

Answer 3

遇到类似的问题并遇到了这个问题。为我修复的是将代码放在片段的onResume方法中。当包含视图对象的片段与设置菜单的活动不同时，这非常有用。

sony_camera_api

如何在首选项更改后更新片段中的textview

3 个答案: