使用SharedPreferences保存字符串

Question

我正在尝试通过点击包含收藏夹的按钮来制作列表视图。此列表视图项目使用1个图像，标题和副标题创建。

我的问题是：似乎在保存项目数量的值时，它总是将值取为1，即使每次单击按钮（处于要添加的状态）此变量递增并存储在共享首选项中。

粘贴代码的重要部分：

List1（活动片段Viewp）

public class List1 extends Fragment {
    public String seleccion;    
    private Context context2;
    private Activity act2;
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        context2 = getActivity().getApplicationContext();
        act2 = this.getActivity();
        View visor = inflater.inflate(R.layout.activity_principal, container, false);

    ListView lista = (ListView) visor.findViewById(R.id.listadirectivos);
    ArrayList<Directivo> arraydir = new ArrayList<Directivo>();
    Directivo directivo;

    // Forma 1: Introduzco los datos por orden alfab�tico
    /*directivo = new Directivo(getResources().getDrawable(R.drawable.abccountry), "ABC ", "Country");
    arraydir.add(directivo);
    directivo = new Directivo(getResources().getDrawable(R.drawable.abcjazz), "ABC  ", "Jazz");
    arraydir.add(directivo);*/
    directivo = new Directivo(getResources().getDrawable(R.drawable.arrowclassicrock), "Arrow Classic Rock", "Rock");
    arraydir.add(directivo);
    directivo = new Directivo(getResources().getDrawable(R.drawable.canalfiesta), "Canal Fiesta", "Radio Party");
    arraydir.add(directivo);
    directivo = new Directivo(getResources().getDrawable(R.drawable.cadenadial), "Cadena Dial", "Radio General");
    arraydir.add(directivo);
    //........

    // Creo el adapter personalizado

    AdapterDirectivos adapter = new AdapterDirectivos(act2, arraydir);

    // Lo aplico
    lista.setAdapter(adapter);
    lista.setOnItemClickListener(new OnItemClickListener() {
        public void onItemClick(AdapterView<?> a, View v, int position, long id) {
            //Link con la radio: en general los que no van son MMS
            String opcionSeleccionada = 
                    ((Directivo)a.getAdapter().getItem(position)).getNombre();
            /*if (opcionSeleccionada == "ABC ") { //no va 
                seleccion = "mms://a952.l11289754951.c112897.g.lm.akamaistream.net/D/952/112897/v0001/reflector:54951";
            }
            else if (opcionSeleccionada == "ABC  ") { //no va
                seleccion = "mms://a134.l11289752133.c112897.g.lm.akamaistream.net/D/134/112897/v0001/reflector:52133";
            }*/
            if (opcionSeleccionada == "Arrow Classic Rock") { //va
                seleccion = "http://91.221.151.155";
            }
            else if (opcionSeleccionada == "Canal Fiesta") { //va
                    seleccion = "http://195.55.74.207/rtva/canalfiestaradio_master.mp3?GKID=3bfcb56203a811e4a80500163e914f69";
                }
            else if (opcionSeleccionada == "Cadena Dial") { //va
                seleccion = "http://194.169.201.177:8085/liveDial.mp3";
            }
            //............
            Intent i = new Intent(context2, Radio.class);
            i.putExtra("seleccion", seleccion);
            i.putExtra("opcionSeleccionada", opcionSeleccionada);
            startActivity(i);
        }

    });

    // Look up the AdView as a resource and load a request.
    AdView adView = (AdView) visor.findViewById(R.id.adView);
    AdRequest adRequest = new AdRequest.Builder().build();
    adView.loadAd(adRequest);


    return visor;
}

}

//“opcionSeleccionada”是ListView的一个项目的标题名称（之后用于创建listview），“选择”在这里并不重要

广播（活动）

public class Radio extends Activity implements
MediaPlayer.OnCompletionListener, MediaPlayer.OnPreparedListener,
MediaPlayer.OnErrorListener, MediaPlayer.OnBufferingUpdateListener {
     private int j=0;
     private int i=0;
     private String TAG = getClass().getSimpleName();
     private MediaPlayer mp = null;
     private boolean dejaractivado=false;
     private Button play;
     private ToggleButton favs;
     private Button stop;
     private TextView textView;
     boolean prevencion = false;

 @Override
 public void onCreate(Bundle icicle) {
     super.onCreate(icicle);
     setContentView(R.layout.activity_main);
     textView = (TextView)findViewById(R.id.TextView1);
     play = (Button) findViewById(R.id.play);
     stop = (Button) findViewById(R.id.stop);
     favs = (ToggleButton) findViewById(R.id.favs);

     play.setOnClickListener(new View.OnClickListener() {
         public void onClick(View view) {
             play();
         }
     });

     favs.setOnClickListener(new View.OnClickListener() {
         public void onClick(View view) {
             if(favs.isChecked()) {
                 addfavs();
             }
             else {
                 delfavs();
             }
         }
     });

     stop.setOnClickListener(new View.OnClickListener() {
         public void onClick(View view) {
             stop();
         }
     });

    // Look up the AdView as a resource and load a request.
        AdView adView = (AdView) this.findViewById(R.id.adView);
        AdRequest adRequest = new AdRequest.Builder().build();
        adView.loadAd(adRequest);

 }

 private void play() {
     Bundle bundle=getIntent().getExtras();
     prevencion = true;
     textView.setText("Conectando con la radio......");
     Uri myUri = Uri.parse(bundle.getString("seleccion"));
     try {
         if (mp == null) {
             this.mp = new MediaPlayer();
         } else {
             mp.stop();
             mp.reset();
         }
         mp.setDataSource(this, myUri); 
         mp.setAudioStreamType(AudioManager.STREAM_MUSIC);
         mp.setOnPreparedListener(this);
         mp.setOnBufferingUpdateListener(this);
         mp.setOnErrorListener(this);
         mp.prepareAsync();

         Log.d(TAG, "LoadClip Done");
     } catch (Throwable t) {
         Log.d(TAG, t.toString());
     }
 }

 @Override
 public void onPrepared(MediaPlayer mp) {
     Log.d(TAG, "Stream is prepared");
     mp.start();
     textView.setText("");
    /* String aux = (String) MediaStore.Audio.Media.ARTIST;
     textView.setText("Estas escuchando: "+aux);
     textView.setText("");*/
     j=1;
 }


 private void addfavs() {
    i++;
    //Toast toast = Toast.makeText(getApplicationContext(), "Bien, metido", Toast.LENGTH_SHORT);
    //toast.show();


    Bundle bundle=getIntent().getExtras();
    String str = bundle.getString("opcionSeleccionada"); // str = Nombre Radio
    //String str2= wmbPreference.getString("opcionSeleccionada",str);
    SharedPreferences shared = getSharedPreferences("guardar", 0);
    SharedPreferences.Editor editor = shared.edit();        
    editor.putString("opcionSeleccionada"+i, str);
    editor.remove("Status_size");
    editor.putInt("Status_size", i);
    editor.commit();// commit is important here.
 }   
 private void delfavs() {
    //it is a prototype:
    SharedPreferences shared = getSharedPreferences("guardar", 0);
    SharedPreferences.Editor editor = shared.edit();
    editor.remove("opcionSeleccionada"+i);
    editor.commit();// commit is important here.
    //String channel = (shared.getString("opcionSeleccionada", ""));

    //Toast toast = Toast.makeText(getApplicationContext(), channel, Toast.LENGTH_SHORT);
    //toast.show();



    //Toast toast = Toast.makeText(getApplicationContext(), "Mal, sacado", Toast.LENGTH_SHORT);
    //toast.show();
 }

 private void stop() {
     if(j==1) {
         textView.setText("");
         mp.stop();
     }
 }

 public void onDestroy() {
     textView.setText("");
     super.onDestroy();
         stop();
  }
 @Override
 public void onStop() {
     textView.setText("");
     super.onStop();
     if(dejaractivado==false) { }
     else {
         stop();
     }
  }

 public void onCompletion(MediaPlayer mp) {
     stop();
 }

（“i”是喜欢的项目的值，“opcionSeleccionadai”是每个项目的字符串名称标题）

Viewp（活动）

公共类Viewp扩展了FragmentActivity实现         ActionBar.TabListener {

private ViewPager viewPager;
private TabsPagerAdapter mAdapter;
private ActionBar actionBar;
// Tab titles   
private Context context = this;
String[] channel = new String[100];
int i; 


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.viewpager);
    // Initilization

    /*context.getSharedPreferences("guardar", 0);
    SharedPreferences shared = getSharedPreferences("guardar", 0);
    i = shared.getInt("Status_size", 0);  
    for(int s=1;s<=i;s++) {
        channel[s] = (shared.getString("opcionSeleccionada"+s, ""));
    }*/

    viewPager = (ViewPager) findViewById(R.id.pager);
    actionBar = getActionBar();
    mAdapter = new TabsPagerAdapter(getSupportFragmentManager());

    viewPager.setAdapter(mAdapter);
    actionBar.setHomeButtonEnabled(false);
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);        




    // Adding Tabs
    actionBar.addTab(actionBar.newTab().setText(getResources().getString(R.string.emisoras))
            .setTabListener(this));
    actionBar.addTab(actionBar.newTab().setText(getResources().getString(R.string.estilo))
            .setTabListener(this));
    actionBar.addTab(actionBar.newTab().setText(getResources().getString(R.string.favoritos))
            .setTabListener(this));



    /*      for (int w=0; w<tabs.length-1; w++) {
        actionBar.addTab(actionBar.newTab().setText(tabs[w])
                .setTabListener(this));
    }*/
    /**
     * on swiping the viewpager make respective tab selected
     * */
    viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {

        @Override
        public void onPageSelected(int position) {
            // on changing the page
            // make respected tab selected
            actionBar.setSelectedNavigationItem(position);
        }

        @Override
        public void onPageScrolled(int arg0, float arg1, int arg2) {
        }

        @Override
        public void onPageScrollStateChanged(int arg0) {
        }
    });
}

@Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
}

@Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
    // on tab selected
    // show respected fragment view
    viewPager.setCurrentItem(tab.getPosition());
}

@Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
}

@Override
public void onResume(){
    super.onResume();

    context.getSharedPreferences("guardar", 0);
    SharedPreferences shared = getSharedPreferences("guardar", 0);

    i = shared.getInt("Status_size", 0);  //i siempre da 1
    for(int j=0; j<i; j++) {
        channel[j] = shared.getString("opcionSeleccionada"+j, "");
    }

}

}

这里，我加载了保存在其他类中的值

List3（Viewp片段）

public class List3 extends Fragment {
    public String seleccion;    
    private Context context;
    private Activity act;
    private String[] myValue;
    private int y=0;
    private boolean primeravez=true;
    //private TextView estilo;
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.activity_principal3, container, false);


    context = getActivity().getApplicationContext();

    act = this.getActivity();
    Directivo directivo;
    ArrayList<Directivo> arraydir2 = new ArrayList<Directivo>();
    AdapterDirectivos2 adapter2 = new AdapterDirectivos2(act, arraydir2);
    Viewp viewp = (Viewp)getActivity();



    myValue = new String[viewp.channel.length];
    for (int k=0; k<myValue.length; k++) {
        myValue[k]=viewp.channel[k];
    }

    for(int i=0; i<myValue.length;i++) {
        if(myValue[i]!=null) {
            if (myValue[i].equals("Esencia Radio")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.esenciaradio), "Esencia Radio", "Radio General");
            else if (myValue[i].equals("I love FM")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.ilovefm), "I Love FM", "Radio General");
            else if (myValue[i].equals("Los 40 Principales")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.los40principales), "Los 40 Principales", "Radio General");
            else if (myValue[i].equals("RAC 105")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.rac105), "RAC 105", "Radio General");
            else if (myValue[i].equals("Sky FM")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.skyfm), "Sky FM", "Radio General");
            else if (myValue[i].equals("Styl FM")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.stylfm), "Styl FM", "Radio General");
            else if (myValue[i].equals("Cocktelera Blues")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.cocktelerablues), "Cocktelera Blues", "General Blues");
            else if (myValue[i].equals("Q fm")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.qfm), "Q fm", "Jazz/Soul/Blues/Funky");
            else if (myValue[i].equals("Radio Clásica RNE")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.radioclasicarne), "Radio Clásica RNE", "Música Clásica");
            else if (myValue[i].equals("Koffee FM")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.koffeeradio), "Koffee FM", "Chill out");
            else if (myValue[i].equals("Ibiza Global Radio")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.ibizaglobalradio), "Ibiza Global Radio", "House/Dance/Electrónica");
            else if (myValue[i].equals("Maxima FM")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.maximafm), "Maxima FM", "Dance/Música Electrónica");
            else if (myValue[i].equals("Cadena Latino")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.cadenalatino), "Cadena Latino", "Latino/Flamenco");
            else if (myValue[i].equals("Chanquete FM")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.chanquetefm), "Chanquete FM", "Flamenco");
            else if (myValue[i].equals("Flamenco Radio")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.flamencoradio), "Flamenco Radio", "Flamenco");
            else if (myValue[i].equals("HotMix Radio")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.hotmixradiofunky), "HotMix Radio Funky", "Funky Mix");
            else if (myValue[i].equals("Sublime FM")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.sublimefm), "Sublime FM", "Jazz/Soul/Funk/Lounge");
            else if (myValue[i].equals("Mix Radio House")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.mixradiohouse), "Mix Radio House", "House");
            else if (myValue[i].equals("Jazz Radio")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.jazzradio), "Jazz Radio", "Jazz");
            else if (myValue[i].equals("SmoothJazz Radio")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.smoothjazz), "SmoothJazz Radio", "Smooth Jazz");
            else if (myValue[i].equals("Canal Fiesta")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.canalfiesta), "Canal Fiesta", "Pop");
            else if (myValue[i].equals("Sky FM ")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.skyfmreggae), "Sky FM ", "Reggae");
            else if (myValue[i].equals("Arrow Classic Rock")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.arrowclassicrock), "Arrow Classic Rock", "Rock");
            else if (myValue[i].equals("HotMix Radio Rock")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.hotmixradiorock), "HotMix Radio Rock", "Rock");
            else if (myValue[i].equals("Rock FM")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.rockfm), "Rock FM", "Rock");
            else if (myValue[i].equals("Rock FM Classic")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.rockfmbelgie), "Rock FM Classic", "Classic Rock");
            else if (myValue[i].equals("Virgin Radio")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.virginradio), "Virgin Radio", "Rock/Hard-Rock");
            else if (myValue[i].equals("Trance FM")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.trancefm), "Trance FM", "Trance");
            else if (myValue[i].equals("M80 Radio")) 
                adapter2.addItem(getResources().getDrawable(R.drawable.m80radio), "M80 Radio", "Best of 70s/80s/90s");
        }
    }

但是，字符串myValue []的向量，与channel []一样，似乎只有1个位置，而其他值为null。因此，我认为在所有过程的一个时刻，“i或Status_size”值被重新声明或者发生了一些罕见的事情。

我认为这就是全部，如果事情不明确请告诉我（我的英语很差）。有人可以帮帮我吗？非常感谢。

Answer 1

首先，我假设频道[]真的是private String channel[] 您应该发布所有相关代码，包括所有数组的所有初始化声明，因为此时我不知道通道数组的大小。

    i = shared.getInt("Status_size", 0);  //i siempre da 1

    channel[i] = (shared.getString("opcionSeleccionada"+i, ""));

在上面的代码中，您声明要加载上一个活动中的所有值。但是这段代码只加载1个值。它将键"opcionSeleccionada"+i处的字符串加载到通道数组的位置i。因此，如果这是填充通道数组的唯一位置，那么它将只有1个值。

要解决此问题，您需要像在片段中所做的那样循环，以使用共享首选项映射中的适当值填充数组

for(int j=0; j < i; j++) {
    channel[j] = shared.getString("opcionSeleccionada"+j, "");
}

在addFavs（）内执行此操作

private void addfavs() {
    SharedPreferences shared = getSharedPreferences("guardar", 0);
    int i = shared.getInt("Status_size", 0);
    i++;
    //Toast toast = Toast.makeText(getApplicationContext(), "Bien, metido", Toast.LENGTH_SHORT);
    //toast.show();

    Bundle bundle=getIntent().getExtras();
    String str = bundle.getString("opcionSeleccionada"); // str = Nombre Radio
    //String str2= wmbPreference.getString("opcionSeleccionada",str);
    SharedPreferences.Editor editor = shared.edit();        
    editor.putString("opcionSeleccionada"+i, str);
    //you do not need to remove a value from shared preferences. If you use the same key then it gets overridden 
    //editor.remove("Status_size");
    editor.putInt("Status_size", i);
    editor.commit();// commit is important here.
 }

您可以删除i作为成员变量，并确保在deleteFavs方法中以相同的方式设置

我希望这会有所帮助。快乐编码

Answer 2

试试这将有助于PreferenceManager.getDefaultSharedPreferences（context）.edit（）。putString（＆＃34; MYLABEL＆＃34;，＆＃34; myStringToSave＆＃34;）。commit（）;