Android中的動態列表使用SharedPreferences

Question

我正在開發一個項目，我需要創建一個動態列表。爲此，我使用共享首選項永久性地將值存儲在列表中。但是當我重新啓動項目時，我進入不是退出。我嘗試了很多時間，但問題沒有解決。
這是我的代碼。
NumberListActivity.java

public class NumberListActivity extends Activity { 
    ListView numList; 
    ArrayList<String> list = new ArrayList<String>(); 
    ArrayAdapter<String> adapter; 
    public static final String Place = "placeKey"; 
    Button btnAdd; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     // TODO Auto-generated method stub 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.custom_list); 
     numList = (ListView) findViewById(R.id.list); 
     btnAdd = (Button) findViewById(R.id.btnAdd); 
     adapter = new ArrayAdapter<String>(this, 
       android.R.layout.simple_list_item_1, list); 
     numList.setAdapter(adapter); 
     btnAdd.setOnClickListener(new OnClickListener() { 

      @Override 
      public void onClick(View v) { 
       // TODO Auto-generated method stub 
       SharedPreferences preferences = getSharedPreferences("place", 
         Context.MODE_PRIVATE); 
       SharedPreferences.Editor spEditor = preferences.edit(); 
       EditText edit = (EditText) findViewById(R.id.txtItem); 
       spEditor.putString("Value", edit.getText().toString()); 
       spEditor.commit(); 
       list.add(preferences.getString("Value", "")); 
       adapter.notifyDataSetChanged(); 

      } 
     }); 
     list.toArray(); 

    } 

}  

custom_list.xml

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    android:orientation="vertical" > 

    <EditText 
     android:id="@+id/txtItem" 
     android:layout_width="240dp" 
     android:layout_height="wrap_content" 
     android:inputType="text" /> 

    <Button 
     android:id="@+id/btnAdd" 
     android:layout_width="fill_parent" 
     android:layout_height="wrap_content" 
     android:layout_toRightOf="@id/txtItem" /> 

    <ListView 
     android:id="@+id/list" 
     android:layout_width="fill_parent" 
     android:layout_height="wrap_content" 
     android:layout_below="@id/txtItem" /> 

    <TextView 
     android:id="@+id/empty" 
     android:layout_width="fill_parent" 
     android:layout_height="wrap_content" 
     android:layout_below="@id/txtItem" 
     android:gravity="center_horizontal" /> 

</RelativeLayout> 

Answer 1

試試這個..

SharedPreferences preferences; 
SharedPreferences.Editor spEditor; 
int count = 0; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    // TODO Auto-generated method stub 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.custom_list); 

    preferences = getSharedPreferences("place", Context.MODE_PRIVATE); 
    spEditor = preferences.edit(); 
    count = preferences.getInt("count", 0); 
    if(count > 0){ 
     for(int i = 0; i < count; i++){ 
      list.add(preferences.getString("Value["+i+"]", "")); 
     }   
    } 

    numList = (ListView) findViewById(R.id.list); 
    btnAdd = (Button) findViewById(R.id.btnAdd); 
    adapter = new ArrayAdapter<String>(this, 
      android.R.layout.simple_list_item_1, list); 
    numList.setAdapter(adapter); 
    btnAdd.setOnClickListener(new OnClickListener() { 

     @Override 
     public void onClick(View v) { 
      // TODO Auto-generated method stub 
      EditText edit = (EditText) findViewById(R.id.txtItem); 
      spEditor.putString("Value["+count+"]", edit.getText().toString()); 
      spEditor.commit(); 
      list.add(preferences.getString("Value["+count+"]", "")); 
      count += 1; 
      spEditor.putInt("count", count); 
      adapter.notifyDataSetChanged(); 

     } 
    }); 
}