多选ListView和SharedPreferences

Question

我想保存多选listview复选框的状态。我有以下布局。

我想要做的是保存的状态，例如，“测试1和TEST3”当我回到这个活动这个checkboxs进行检查。我正在使用共享首选项。我有以下代码。

这会将我的名单：

mList = (ListView) findViewById(R.id.ListViewTarefas);  
    final TarefaDbAdapter db = new TarefaDbAdapter(this); 
    db.open(); 
    data = db.getAllTarefas(getIntent().getExtras().get("nomeUtilizadorTarefa").toString()); 
    adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_multiple_choice,data); 
    mList.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE); 
    mList.setAdapter(adapter); 
    LoadSelections(); 

，这是下面的代码加载和保存的checkboxs（据说）的状态。

@Override 
protected void onPause() { 
    // always handle the onPause to make sure selections are saved if user clicks back button 
    SaveSelections(); 
    super.onPause(); 
} 

private void ClearSelections() { 
    // user has clicked clear button so uncheck all the items 
    int count = this.mList.getAdapter().getCount(); 
    for (int i = 0; i < count; i++) { 
     this.mList.setItemChecked(i, false); 
    } 
    // also clear the saved selections 
    SaveSelections(); 
} 

private void LoadSelections() { 
    // if the selections were previously saved load them 
    SharedPreferences settingsActivity = getPreferences(MODE_PRIVATE); 
    if (settingsActivity.contains(data.toString())) { 
     String savedItems = settingsActivity.getString(data.toString(), ""); 
     this.data.addAll(Arrays.asList(savedItems.split(","))); 
     int count = this.mList.getAdapter().getCount(); 
     for (int i = 0; i < count; i++) { 
      String currentItem = (String) this.mList.getAdapter().getItem(i); 
      if (this.data.contains(currentItem)) { 
       this.mList.setItemChecked(i, true); 
      } 
     } 
    } 
} 


private void SaveSelections() { 
    // save the selections in the shared preference in private mode for the user 
    SharedPreferences settingsActivity = getPreferences(MODE_PRIVATE); 
    SharedPreferences.Editor prefEditor = settingsActivity.edit(); 
    String savedItems = getSavedItems(); 
    prefEditor.putString(data.toString(), savedItems); 
    prefEditor.commit(); 
} 


private String getSavedItems() { 
    String savedItems = ""; 
    int count = this.mList.getAdapter().getCount(); 
    for (int i = 0; i < count; i++) { 
     if (this.mList.isItemChecked(i)) { 
      if (savedItems.length() > 0) { 
       savedItems += "," + this.mList.getItemAtPosition(i); 
      } else { 
       savedItems += this.mList.getItemAtPosition(i); 
      } 
     } 
    } 
    return savedItems; 
} 

比我加载按钮中的SaveSelections和清除选择方法。

问题是这不起作用。有人可以帮我吗？

我的问候。

Answer 1

我最近碰到类似的问题。这很可能是因为ListView中的项目正在被回收（属性和全部）。你应该明确地设置那些没有保存到未选中状态的。

编辑： 此外，尽管我可能是误会，我不认为你应该将你保存字符串的“数据”，因为这是你的适配器使用什么来生成列表，不是吗？

试试这个：

private void LoadSelections() { 
    // if the selections were previously saved load them 
    SharedPreferences settingsActivity = getPreferences(MODE_PRIVATE); 
    if (settingsActivity.contains(data.toString())) { 
     String savedItems = settingsActivity.getString(data.toString(), ""); 
     ArrayList<String> savedItemsList = (ArrayList<String>) Arrays.asList(savedItems.split(",")); 
     int count = this.mList.getAdapter().getCount(); 
     for (int i = 0; i < count; i++) { 
      String currentItem = (String) this.mList.getAdapter().getItem(i); 
      if (savedItemList.contains(currentItem)) { 
       this.mList.setItemChecked(i, true); 
      } else { 
       this.mList.setItemChecked(i, false); 
      } 
     } 
    } 
} 

我希望它为你的作品！