android - リスト設定からオプションを非表示にする

Question

設定オプションにリスト設定がある非常に不完全なAndroidプロジェクトがあります。私がやりたいことは、リストからキャラクターブラックリストオプションを永久に非表示にしますが、内部的には機能します。このために私はやった

<EditTextPreference android:key="preference_character_blacklist"
        android:title="Character blacklist"
        android:visibility="gone"/>

しかし、うまくいきませんでした。むしろ、プロジェクトの実行後に設定に移動したときにエラーが表示されました。設定は次のようになります-file:///home/Piyal/Desktop/Screenshot.png 私のpreference.xmlは-

<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">

<!-- GENERAL SETTINGS -->
<PreferenceCategory android:title="General settings">

    <CheckBoxPreference android:key="preference_capture_continuous"
        android:title="Continuous preview"
        android:entries="@array/capturemodes" />

    <ListPreference android:title="Recognize"
        android:key="sourceLanguageCodeOcrPref"
        android:entries="@array/languagenames"
        android:entryValues="@array/iso6393" />

</PreferenceCategory>

<!-- TRANSLATION SETTINGS -->
<PreferenceCategory android:title="Translation settings"
                    >

    <CheckBoxPreference android:key="preference_translation_toggle_translation"
        android:title="Translate"/>

    <ListPreference android:key="targetLanguageCodeTranslationPref"  
        android:title="Translate to"
        android:dependency="preference_translation_toggle_translation"
        android:entries="@array/translationtargetlanguagenames_google" 
        android:entryValues="@array/translationtargetiso6391_google" />

    <ListPreference android:key="preference_translator" 
        android:title="Translator"
        android:dependency="preference_translation_toggle_translation"
        android:entries="@array/translators" 
        android:entryValues="@array/translators"

         />


</PreferenceCategory>

<!-- ADVANCED SETTINGS -->
<PreferenceCategory android:title="Advanced settings">

    <ListPreference android:key="preference_ocr_engine_mode"
        android:title="OCR engine"
        android:entries="@array/ocrenginemodes"
        android:entryValues="@array/ocrenginemodes"/>

    <ListPreference android:key="preference_operator_mode"
        android:title="Operator"
        android:entries="@array/operatormodes"
        android:entryValues="@array/operatormodes"
        />

    <CheckBoxPreference
        android:key="preferences_auto_focus"
        android:title="Autofocus"/>

    <CheckBoxPreference
        android:key="preferences_play_beep"
        android:title="Beep"/>

    <EditTextPreference android:key="preference_character_blacklist"
        android:title="Character blacklist"/>

    <EditTextPreference

        android:key="preference_character_whitelist"
        android:title="Character whitelist"

        />


 <!-- 
    <CheckBoxPreference
        android:key="preference_toggle_light"
        android:title="Light"/>
-->

    <ListPreference android:key="preference_page_segmentation_mode"
        android:title="Page segmentation"
        android:entries="@array/pagesegmentationmodes"
        android:entryValues="@array/pagesegmentationmodes" />

    <CheckBoxPreference
        android:key="preferences_reverse_image"
        android:title="Reversed camera image"
        android:summary="(For devices with only a front camera)"/>

</PreferenceCategory>

  </PreferenceScreen>`

これが私の優先アクティビティです-

    public class PreferencesActivity extends PreferenceActivity implements
  OnSharedPreferenceChangeListener {

  // Preference keys not carried over from R.M Theis project project
  public static final String KEY_OPERATOR_MODE = "preference_operator_mode";


  // Preference keys not carried over from ZXing project
  public static final String KEY_SOURCE_LANGUAGE_PREFERENCE = 

  "sourceLanguageCodeOcrPref";
  public static final String KEY_TARGET_LANGUAGE_PREFERENCE =  

"targetLanguageCodeTranslationPref";
  public static final String KEY_TOGGLE_TRANSLATION = 

"preference_translation_toggle_translation";
  public static final String KEY_CONTINUOUS_PREVIEW = 

"preference_capture_continuous";
  public static final String KEY_PAGE_SEGMENTATION_MODE = 

"preference_page_segmentation_mode";
  public static final String KEY_OCR_ENGINE_MODE = "preference_ocr_engine_mode";
  public static final String KEY_CHARACTER_BLACKLIST = 

"preference_character_blacklist";
  public static final String KEY_CHARACTER_WHITELIST = 

"preference_character_whitelist";
  public static final String KEY_TOGGLE_LIGHT = "preference_toggle_light";
  public static final String KEY_TRANSLATOR = "preference_translator";

  // Preference keys carried over from ZXing project
  public static final String KEY_AUTO_FOCUS = "preferences_auto_focus";
  public static final String KEY_HELP_VERSION_SHOWN = 

"preferences_help_version_shown";
  public static final String KEY_NOT_OUR_RESULTS_SHOWN = 

"preferences_not_our_results_shown";
  public static final String KEY_REVERSE_IMAGE = "preferences_reverse_image";
  public static final String KEY_PLAY_BEEP = "preferences_play_beep";
  public static final String KEY_VIBRATE = "preferences_vibrate";

  public static final String TRANSLATOR_BING = "Bing Translator";
  public static final String TRANSLATOR_GOOGLE = "Google Translate";

  //private CheckBoxPreference checkBoxPreferenceContinuousPreview;
  private ListPreference listPreferenceSourceLanguage;
  //private CheckBoxPreference checkBoxTranslate;
  private ListPreference listPreferenceTargetLanguage;  
  private ListPreference listPreferenceTranslator;
  private ListPreference listPreferenceOcrEngineMode;
  //private CheckBoxPreference checkBoxBeep;
  private EditTextPreference editTextPreferenceCharacterBlacklist;
  private EditTextPreference editTextPreferenceCharacterWhitelist;
  private ListPreference listPreferencePageSegmentationMode;
  //private CheckBoxPreference checkBoxReversedImage;

  private ListPreference listPreferenceOperatorMode;

  private static SharedPreferences sharedPreferences;

  /**
   * Set the default preference values.
   * 
   * @param Bundle
   *            savedInstanceState the current Activity's state, as passed by
   *            Android
   */
  @Override
  protected void onCreate(Bundle savedInstanceState) 
  {
    super.onCreate(savedInstanceState);
    getWindow().setBackgroundDrawableResource(R.drawable.background_holo_dark);
    addPreferencesFromResource(R.xml.preferences);

    sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);

    //checkBoxPreferenceContinuousPreview = (CheckBoxPreference) 

getPreferenceScreen().findPreference(KEY_CONTINUOUS_PREVIEW);
    listPreferenceSourceLanguage = (ListPreference) 

getPreferenceScreen().findPreference(KEY_SOURCE_LANGUAGE_PREFERENCE);
    //checkBoxTranslate = (CheckBoxPreference) 

getPreferenceScreen().findPreference(KEY_TOGGLE_TRANSLATION);
    listPreferenceTargetLanguage = (ListPreference) 

getPreferenceScreen().findPreference(KEY_TARGET_LANGUAGE_PREFERENCE);
    listPreferenceTranslator = (ListPreference) 

getPreferenceScreen().findPreference(KEY_TRANSLATOR);    
    listPreferenceOcrEngineMode = (ListPreference) 

getPreferenceScreen().findPreference(KEY_OCR_ENGINE_MODE);
    listPreferenceOperatorMode = (ListPreference)  

getPreferenceScreen().findPreference(KEY_OPERATOR_MODE);

    //checkBoxBeep = (CheckBoxPreference) 

getPreferenceScreen().findPreference(KEY_PLAY_BEEP);
    editTextPreferenceCharacterBlacklist = (EditTextPreference) 
getPreferenceScreen().findPreference(KEY_CHARACTER_BLACKLIST);
    editTextPreferenceCharacterWhitelist = (EditTextPreference) 
getPreferenceScreen().findPreference(KEY_CHARACTER_WHITELIST);
    listPreferencePageSegmentationMode = (ListPreference) 
getPreferenceScreen().findPreference(KEY_PAGE_SEGMENTATION_MODE);
    //checkBoxReversedImage = (CheckBoxPreference) 
getPreferenceScreen().findPreference(KEY_REVERSE_IMAGE);

    // Create the entries/entryvalues for the translation target language list.
    initTranslationTargetList();

  }

  /**
   * Interface definition for a callback to be invoked when a shared
   * preference is changed. Sets summary text for the app's preferences. Summary  
text values show the
   * current settings for the values.
   * 
   * @param sharedPreferences
   *            the Android.content.SharedPreferences that received the change
   * @param key
   *            the key of the preference that was changed, added, or removed
   */
  @Override
  public void onSharedPreferenceChanged(SharedPreferences sharedPreferences,
      String key) {    
    // Update preference summary values to show current preferences
    if (key.equals(KEY_TRANSLATOR)) {
      listPreferenceTranslator.setSummary(sharedPreferences.getString(key, 
CaptureActivity.DEFAULT_TRANSLATOR));
    } else if(key.equals(KEY_SOURCE_LANGUAGE_PREFERENCE)) {

      // Set the summary text for the source language name

  listPreferenceSourceLanguage.
setSummary(LanguageCodeHelper.getOcrLanguageName(getBaseContext(),  
sharedPreferences.getString(key,         
CaptureActivity.DEFAULT_SOURCE_LANGUAGE_CODE)));

      // Retrieve the character blacklist/whitelist for the new language
      String blacklist = OcrCharacterHelper.getBlacklist(sharedPreferences, 
listPreferenceSourceLanguage.getValue());
      String whitelist = OcrCharacterHelper.getWhitelist(sharedPreferences, 
listPreferenceSourceLanguage.getValue());

      // Save the character blacklist/whitelist to preferences
      sharedPreferences.edit().putString(KEY_CHARACTER_BLACKLIST, 
blacklist).commit();
      sharedPreferences.edit().putString(KEY_CHARACTER_WHITELIST, 
whitelist).commit();

      // Set the blacklist/whitelist summary text
      editTextPreferenceCharacterBlacklist.setSummary(blacklist);
      editTextPreferenceCharacterWhitelist.setSummary(whitelist);

    } else if (key.equals(KEY_TARGET_LANGUAGE_PREFERENCE)) {

listPreferenceTargetLanguage.
setSummary(LanguageCodeHelper.getTranslationLanguageName(this,  
sharedPreferences.getString(key,        
CaptureActivity.DEFAULT_TARGET_LANGUAGE_CODE)));
        } else if (key.equals(KEY_PAGE_SEGMENTATION_MODE)) {

listPreferencePageSegmentationMode.setSummary(sharedPreferences.getString(key,  
CaptureActivity.DEFAULT_PAGE_SEGMENTATION_MODE));
    } else if (key.equals(KEY_OCR_ENGINE_MODE)) {
      listPreferenceOcrEngineMode.setSummary(sharedPreferences.getString(key,  
CaptureActivity.DEFAULT_OCR_ENGINE_MODE));
    }
    else if (key.equals(KEY_OPERATOR_MODE))
    {
        listPreferenceOperatorMode.setSummary(sharedPreferences.getString(key, 
CaptureActivity.DEFAULT_OPERATOR_MODE));
    }  
    else if (key.equals(KEY_CHARACTER_BLACKLIST)) {  

      // Save a separate, language-specific character blacklist for this language
      OcrCharacterHelper.setBlacklist(sharedPreferences, 
          listPreferenceSourceLanguage.getValue(), 
          sharedPreferences.getString(key, 
OcrCharacterHelper.getDefaultBlacklist(listPreferenceSourceLanguage.getValue())));

      // Set the summary text
    editTextPreferenceCharacterBlacklist.
setSummary(sharedPreferences.getString(key, 
OcrCharacterHelper.getDefaultBlacklist(listPreferenceSourceLanguage.getValue())));

    } else if (key.equals(KEY_CHARACTER_WHITELIST)) {

      // Save a separate, language-specific character blacklist for this language
      OcrCharacterHelper.setWhitelist(sharedPreferences, 
          listPreferenceSourceLanguage.getValue(), 
          sharedPreferences.getString(key, 
OcrCharacterHelper.getDefaultWhitelist(listPreferenceSourceLanguage.getValue())));

      // Set the summary text
      editTextPreferenceCharacterWhitelist.
setSummary(sharedPreferences.getString(key, 
OcrCharacterHelper.getDefaultWhitelist  
(listPreferenceSourceLanguage.getValue())));

    }

    // Update the languages available for translation based on the current 
translator selected.
    if (key.equals(KEY_TRANSLATOR)) {
      initTranslationTargetList();
    }

  }

  /**
   * Sets the list of available languages and the current target language for 
translation. Called
   * when the key for the current translator is changed.
   */
  void initTranslationTargetList() {
    // Set the preference for the target language code, in case we've just 
switched from Google
    // to Bing, or Bing to Google.
    String currentLanguageCode = 
sharedPreferences.getString(KEY_TARGET_LANGUAGE_PREFERENCE, 
        CaptureActivity.DEFAULT_TARGET_LANGUAGE_CODE);

    // Get the name of our language
    String currentLanguage = 
LanguageCodeHelper.getTranslationLanguageName(getBaseContext(), 
        currentLanguageCode);
    String[] translators = getResources().getStringArray(R.array.translators);
    String translator = sharedPreferences.getString(KEY_TRANSLATOR, 
CaptureActivity.DEFAULT_TRANSLATOR);
    String newLanguageCode = "";
    if (translator.equals(translators[0])) { // Bing
      // Update the list of available languages for the currently-chosen 
translation API.

listPreferenceTargetLanguage.
setEntries(R.array.translationtargetlanguagenames_microsoft);
      listPreferenceTargetLanguage.
setEntryValues(R.array.translationtargetiso6391_microsoft);

      // Get the corresponding code for our language name
      newLanguageCode = TranslatorBing.toLanguage(currentLanguage);
    } else if (translator.equals(translators[1])) { // Google
      // Update the list of available languages for the currently-chosen 
translation API.
      listPreferenceTargetLanguage.
setEntries(R.array.translationtargetlanguagenames_google);
      listPreferenceTargetLanguage.
setEntryValues(R.array.translationtargetiso6391_google);

      // Get the corresponding code for our language name      
      newLanguageCode = TranslatorGoogle.toLanguage(currentLanguage);
    }

    // Store the code as the target language preference
    String newLanguageName = LanguageCodeHelper.
getTranslationLanguageName(getBaseContext(),
        newLanguageCode);
    listPreferenceTargetLanguage.
setValue(newLanguageName); // Set the radio button in the list

sharedPreferences.edit().putString(PreferencesActivity.KEY_TARGET_LANGUAGE_PREFERENCE, 
        newLanguageCode).commit();
    listPreferenceTargetLanguage.setSummary(newLanguageName);
  }

  /**
   * Sets up initial preference summary text
   * values and registers the OnSharedPreferenceChangeListener.
   */
  @Override
  protected void onResume() {
    super.onResume();
    // Set up the initial summary values
    listPreferenceTranslator.
setSummary(sharedPreferences.getString(KEY_TRANSLATOR, 
CaptureActivity.DEFAULT_TRANSLATOR));
    listPreferenceSourceLanguage.
setSummary(LanguageCodeHelper.getOcrLanguageName(getBaseContext(), 
sharedPreferences.getString     
(KEY_SOURCE_LANGUAGE_PREFERENCE, CaptureActivity.DEFAULT_SOURCE_LANGUAGE_CODE)));
    listPreferenceTargetLanguage.
setSummary(LanguageCodeHelper.getTranslationLanguageName(getBaseContext(), 
sharedPreferences.getString 
(KEY_TARGET_LANGUAGE_PREFERENCE, CaptureActivity.DEFAULT_TARGET_LANGUAGE_CODE)));
    listPreferencePageSegmentationMode.
setSummary(sharedPreferences.getString(KEY_PAGE_SEGMENTATION_MODE,
    CaptureActivity.DEFAULT_PAGE_SEGMENTATION_MODE));
    listPreferenceOcrEngineMode.
setSummary(sharedPreferences.getString(KEY_OCR_ENGINE_MODE, 
CaptureActivity.DEFAULT_OCR_ENGINE_MODE));
    listPreferenceOperatorMode.
setSummary(sharedPreferences.getString(KEY_OPERATOR_MODE, 
CaptureActivity.DEFAULT_OPERATOR_MODE));
    editTextPreferenceCharacterBlacklist.
setSummary(sharedPreferences.getString(KEY_CHARACTER_BLACKLIST,     
OcrCharacterHelper.getDefaultBlacklist(listPreferenceSourceLanguage.getValue())));
   editTextPreferenceCharacterWhitelist.
setSummary(sharedPreferences.getString
(KEY_CHARACTER_WHITELIST,OcrCharacterHelper.getDefaultWhitelist 
(listPreferenceSourceLanguage.getValue())));

    // Set up a listener whenever a key changes
    getPreferenceScreen().
getSharedPreferences().registerOnSharedPreferenceChangeListener(this);
  }

  /**
   * Called when Activity is about to lose focus. Unregisters the
   * OnSharedPreferenceChangeListener.
   */
  @Override
  protected void onPause() {
    super.onPause();
    getPreferenceScreen().
getSharedPreferences().unregisterOnSharedPreferenceChangeListener(this);
  }
}

`

getPreferenceScreen().removePreference(editTextPreferenceCharacterBlacklist); を追加した後のスタックトレース

onCreate() で。

05-30 17:42:00.546: E/AndroidRuntime(379): FATAL EXCEPTION: main

05-30 17:42:00.546: E/AndroidRuntime(379): java.lang.RuntimeException: Unable to start 
activity  
ComponentInfo{automated.card.recharge.ocr/automated.card.
recharge.ocr.PreferencesActivity}: java.lang.NullPointerException
05-30 17:42:00.546: E/AndroidRuntime(379):  at 
android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)

05-30 17:42:00.546: E/AndroidRuntime(379):  at 
android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)

05-30 17:42:00.546: E/AndroidRuntime(379):  at 
android.app.ActivityThread.access$1500(ActivityThread.java:117)

05-30 17:42:00.546: E/AndroidRuntime(379):  at 
android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)

05-30 17:42:00.546: E/AndroidRuntime(379):  at 
android.os.Handler.dispatchMessage(Handler.java:99)

05-30 17:42:00.546: E/AndroidRuntime(379):  at android.os.Looper.loop(Looper.java:123)

05-30 17:42:00.546: E/AndroidRuntime(379):  at 
android.app.ActivityThread.main(ActivityThread.java:3683)

05-30 17:42:00.546: E/AndroidRuntime(379):  at 
java.lang.reflect.Method.invokeNative(Native Method)

05-30 17:42:00.546: E/AndroidRuntime(379):  at 
java.lang.reflect.Method.invoke(Method.java:507)

05-30 17:42:00.546: E/AndroidRuntime(379):  at 
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)

05-30 17:42:00.546: E/AndroidRuntime(379):  at 
com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)

05-30 17:42:00.546: E/AndroidRuntime(379):  at dalvik.system.NativeStart.main(Native 
Method)

05-30 17:42:00.546: E/AndroidRuntime(379): Caused by: java.lang.NullPointerException

05-30 17:42:00.546: E/AndroidRuntime(379):  at 
android.preference.PreferenceGroup.removePreferenceInt(PreferenceGroup.java:181)

05-30 17:42:00.546: E/AndroidRuntime(379):  at 

android.preference.PreferenceGroup.removePreference(PreferenceGroup.java:174) 

05-30 17:42:00.546: E/AndroidRuntime(379):  at 
automated.card.recharge.ocr.PreferencesActivity.onCreate(PreferencesActivity.java:103)

05-30 17:42:00.546: E/AndroidRuntime(379):  at 
android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)

05-30 17:42:00.546: E/AndroidRuntime(379):  at 
android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)

05-30 17:42:00.546: E/AndroidRuntime(379):  at  
com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)

05-30 17:42:00.546: E/AndroidRuntime(379):  at dalvik.system.NativeStart.main(Native  
Method)

05-30 17:42:00.546: E/AndroidRuntime(379): Caused by: java.lang.NullPointerException

05-30 17:42:00.546: E/AndroidRuntime(379):  at 
android.preference.PreferenceGroup.removePreferenceInt(PreferenceGroup.java:181)

05-30 17:42:00.546: E/AndroidRuntime(379):  at 
android.preference.PreferenceGroup.removePreference(PreferenceGroup.java:174)

05-30 17:42:00.546: E/AndroidRuntime(379):  at 
automated.card.recharge.ocr.PreferencesActivity.onCreate(PreferencesActivity.java:103)

05-30 17:42:00.546: E/AndroidRuntime(379):  at 
android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)

05-30 17:42:00.546: E/AndroidRuntime(379):  at 
android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)

score 1 · Accepted Answer

次のものを削除できるはずです。

<EditTextPreference android:key="preference_character_blacklist"
        android:title="Character blacklist"
        android:visibility="gone"/>

あなたのpreferences.xmlから。これにより、設定メニューに表示されなくなります。

設定が内部的に機能するようにするには、SharedPreferencesを読むことをお勧めします。Android ストレージオプションガイドでは、を使用して設定値を保存および取得する方法について説明していますSharedPreferences。

上記のリンクのガイドから文字列を保存するように、次の例を変更しました。

public class Calc extends Activity {
    public static final String PREFS_NAME = "MyPrefsFile";

    @Override
    protected void onCreate(Bundle state){
       super.onCreate(state);
       . . .

       // Restore preferences
       SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
       String silent = settings.getString("character_blacklist", "");
    }

    @Override
    protected void onStop(){
       super.onStop();

      // We need an Editor object to make preference changes.
      // All objects are from android.context.Context
      SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
      SharedPreferences.Editor editor = settings.edit();
      //Some test characters for the blacklist
      mBlackListChars = "a,g,t,h,f";
      editor.putString("character_blacklist", mBlackListChars);

      // Commit the edits
      editor.commit();
    }
}

onCreate()これらのメソッドをおよびの外で呼び出したい場合があることに注意してくださいonStop()。これは純粋に説明のためのものです。さらに、複数の文字を格納するのに役立つ可能性のあるSharedPreferencesを処理できるという事実に注目してください。の方法をStringSet参照してください。getStringSet()SharedPreferences

アップデート

設定を保持し、ユーザーから非表示にするために、プログラムで削除できます。ちょっとしたハックのようですが、これを「PreferenceActivity」の「OnCreate()」に追加することを検討してください

getPreferenceScreen().removePreference(editTextPreferenceCharacterBlacklist);

アップデート

editTextPreferenceCharacterBlacklist が null であるために問題が発生しているようです。指定した行を実行している時点でインスタンス変数に設定されていないため、問題が発生しました。次のようにして見つけることができます。

getPreferenceScreen().removePreference(getPreferenceScreen().findPreference(KEY_CHARACTER_BLACKLIST));

android - リスト設定からオプションを非表示にする

1 に答える 1

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