爲什麼在ActionMode中isItemChecked（）返回true？

Question

我已經設置了一個ActionMode回調，用作ActionBarSherlock使用項目中的上下文ActionBar（CAB）。

我試圖設置多個選擇，以便我可以刪除ListView中的多個項目。

我注意到在調試時，當環境ActionBar（CAB）是不開放的，我叫isItemChecked()一個列表項，我摸，它因爲它應該返回false。但是當CAB打開時，我接觸到的項目（我以前沒有碰過）在撥打isItemChecked()時返回true。然後，當我調用getCheckedItemIds()的數組上的delete時，該數組不包含以前返回爲isItemChecked()的項。

有沒有人看到這個？

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.habit); 
    habitListView = (ListView)findViewById(R.id.habitsListView); 
    habitListView.setAdapter(mAdapter); 
    habitListView.setChoiceMode(AbsListView.CHOICE_MODE_MULTIPLE); 
    habitListView.setItemsCanFocus(false); 
    habitListView.setOnItemLongClickListener(new MyOnItemLongClickListener()); 
    habitListView.setOnItemClickListener(new OnItemClickListener() { 

     @Override 
     public void onItemClick(AdapterView<?> parent, View view, int position, long id) { 
      if (habitListView.isItemChecked(position)) { // for debugging, returns false here 
                 // when CAB isnt up. 
       int h = 2; 
      } 
      // handle differently when CAB is on. 
      if (mMode != null) { 
       if (habitListView.isItemChecked(position)) { // returns true here when CAB is up 
                  // but this is the first time I'm 
                  // clicking the item 
        habitListView.setItemChecked(position, false); 
        // turn CAB off if this is the last to be unchecked 
        if (habitListView.getCheckedItemIds().length == 0) { 
         mMode.finish(); 
        } 
       } else { 
        habitListView.setItemChecked(position, true); 
       } 
      } else { 
       // start detail/edit view activity 
      } 
     } 
    }); 
} 

@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    // Inflate the menu; this adds items to the action bar if it is present. 
    getSupportMenuInflater().inflate(R.menu.activity_main, menu); 
    return true; 
} 

@Override 
public boolean onOptionsItemSelected(MenuItem item) { 
    // Handle item selection 
    switch (item.getItemId()) { 
    case R.id.menu_create: 
     Habit test = new Habit("FLOSS", "GOOD", "", ""); 
     mDbHelper.createHabitEntry(test); 
     mAdapter.changeCursor(mDbHelper.getAllEntries()); 
     break; 
    } 
    return false; 
} 

private class MyOnItemLongClickListener implements OnItemLongClickListener { 
    @Override 
    public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) { 
     habitListView.setItemChecked(position, true); 
     mMode = startActionMode(new MyActionModeCallback()); 
     return true; 
    } 
} 

private class MyActionModeCallback implements ActionMode.Callback { 
    @Override 
    public boolean onPrepareActionMode(ActionMode mode, Menu menu) { 
     // TODO Auto-generated method stub 
     return false; 
    } 

    @Override 
    public void onDestroyActionMode(ActionMode mode) { 
     habitListView.setOnItemLongClickListener(new MyOnItemLongClickListener()); 
    } 

    @Override 
    public boolean onCreateActionMode(ActionMode mode, Menu menu) { 
     mode.getMenuInflater().inflate(R.menu.main_long_click_context, menu); 
     habitListView.setOnItemLongClickListener(null); 
     return true; 
    } 

    @Override 
    public boolean onActionItemClicked(ActionMode mode, MenuItem item) { 
     switch (item.getItemId()) { 
     case R.id.menu_delete: 
      long[] selected = habitListView.getCheckedItemIds(); 
      if (selected.length > 0) { 
       for (long id : selected) { 
        mDbHelper.deleteEntry(id); 
       } 
      } 
      mAdapter.changeCursor(mDbHelper.getAllEntries()); 
      mode.finish(); 
      break; 
     } 
     return true; 
    } 
}; 

Answer 1

那麼是什麼工作對我來說是隻使用

habitListView.setOnItemClickListener(new OnItemClickListener(){ 

     @Override 
     public void onItemClick(AdapterView<?> parent, View view, 
       int position, long id) { 

      //handle differently when CAB is on. 
      if (mMode != null){ 

       view.setSelected(!view.isSelected()); 

       updateCABtitle(); 

       //turn CAB off if this is the last to be unchecked 
        if (habitListView.getCheckedItemIds().length == 0){ 
         mMode.finish(); 
        } 

      } else { 
       //start detail/edit view activity 
       Intent intent = new Intent(getApplicationContext(), HabitDetailActivity.class); 
       startActivity(intent); 

      } 

     } 

    }); 

和

private class MyOnItemLongClickListener implements OnItemLongClickListener{ 

    @Override 
    public boolean onItemLongClick(AdapterView<?> parent, View view, 
        int position, long id) { 


      habitListView.setItemChecked(position, true); 

      mMode = startActionMode(new MyActionModeCallback()); 
      updateCABtitle(); 

      return true; 
    } 

} 

我真的不明白爲什麼setItemChecked()不是爲onItemClick()工作，但似乎是onItemLongClick()。它看起來好像有一個默認的點擊處理程序在AbsListView.PerformItemClick()中被調用，它必須做一些切換選中/未選中或某事。