Android的錯誤行爲爲列表視圖選擇/取消選擇所有複選框操作

Question

我有一個listView與複選框和列表中的第一個複選框是一個選擇/取消選擇所有複選框。

List<CheckedItem> items = new ArrayList<CheckedItem>(); 
    // items.add(new CheckedItem(getResources().getString(R.string.select_all),getResources().getString(R.string.select_all))); 
    adapter = new DownloadDocsListViewAdapter(getContext(), items); 
    adapter.registerDataSetObserver(new DataSetObserver() { 
     @Override 
     public void onChanged() { 
      SparseBooleanArray sparseArray = adapter.getBooleanArray(); 
      isAtLeastOneElementChecked = false; 
      for(int i = 0; i < sparseArray.size(); i++) { 
       int key = sparseArray.keyAt(i); 
       // get the object by the key. 
       boolean obj = sparseArray.get(key); 
       if (i == 0) { 
        for (int j=0; j < listView.getAdapter().getCount(); j++) { 
         CheckedItem checkedItem = (CheckedItem) listView.getAdapter().getItem(i); 
         checkedItem.setChecked(obj); 
        } 
       } 
       if (obj == true) { 
        isAtLeastOneElementChecked = true; 
        break; 
       } 
      } 

      getActivity().invalidateOptionsMenu(); 
     } 
    }); 

    listView.setAdapter(adapter); 
    listView.setOnItemClickListener(this); 
    //add the select All checkbox 
    adapter.add(new CheckedItem(getResources().getString(R.string.select_all),getResources().getString(R.string.select_all))); 

這是清單

public class DownloadDocsListViewAdapter extends ArrayAdapter<CheckedItem> implements CompoundButton.OnCheckedChangeListener { 

    private SparseBooleanArray booleanArray = new SparseBooleanArray(); 

    public DownloadDocsListViewAdapter(Context context, List<CheckedItem> objects) { 
     super(context, R.layout.generated_multiple_docs_item, objects); 

     for (CheckedItem checkedItem : objects) { 
      objects.add(checkedItem); 
     } 

    } 

    @Override 
    public View getView(int position, View convertView, ViewGroup parent) { 
     // Get the data item for this position 
     CheckedItem item = getItem(position);  
     // Check if an existing view is being reused, otherwise inflate the view 
     if (convertView == null) { 
      convertView = LayoutInflater.from(getContext()).inflate(R.layout.download_docs_item, parent, false); 
     } 

     // Populate the data into the template view using the data object 
     TextView tvName = (TextView) convertView.findViewById(R.id.itemTextId); 
     tvName.setText(item.getValue()); 

     CheckBox checkBoxView = (CheckBox) convertView.findViewById(R.id.checkBoxViewId); 
     checkBoxView.setOnCheckedChangeListener(this); 
     checkBoxView.setTag(position); 

     return convertView; 
    } 

    @Override 
    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { 
     int position = Integer.parseInt(buttonView.getTag().toString()); 
     CheckedItem item = getItem(position); 
     booleanArray.put(position, isChecked); 
     item.setChecked(isChecked); 

     notifyDataSetChanged(); 
    } 

    public SparseBooleanArray getBooleanArray() { 
     return booleanArray; 
    } 
} 

ListView的複選框狀態改變的適配器，但列表視圖元素不會出現選中或取消選中。

Answer 1

我在這裏發佈答案。也許會對某人有用。

適配器類：

public class DownloadDocsListViewAdapter extends ArrayAdapter<CheckedItem> implements CompoundButton.OnCheckedChangeListener { 

    private SparseBooleanArray booleanArray = new SparseBooleanArray(); 
    private List<CheckedItem> objects; 
    public DownloadDocsListViewAdapter(Context context, List<CheckedItem> objects) { 
     super(context, R.layout.generated_multiple_docs_item, objects); 
     this.objects = objects; 
    } 

    @Override 
    public View getView(int position, View convertView, ViewGroup parent) { 
     View row = convertView; 
     ViewHolder holder = null; 
     if (row == null) { 
      row = LayoutInflater.from(getContext()).inflate(R.layout.download_docs_item, parent, false); 
      // Populate the data into the template view using the data object 
      holder = new ViewHolder(); 
      holder.name = (TextView) row.findViewById(R.id.itemTextId); 
      holder.checkedBox = (CheckBox) row.findViewById(R.id.checkBoxViewId); 

      row.setTag(holder); 
     } else { 
      holder = (ViewHolder) row.getTag(); 
     } 

     // Get the data item for this position 
     CheckedItem item = objects.get(position); 
     holder.name.setText(item.getValue()); 
     holder.checkedBox.setChecked(item.isChecked()); 
     holder.checkedBox.setOnCheckedChangeListener(this); 
     holder.checkedBox.setTag(position); 

     return row; 
    } 

    @Override 
    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { 
     int position = Integer.parseInt(buttonView.getTag().toString()); 
     if (position == 0) { 
      changeSelectionForAllItems(isChecked); 
     } else { 
      CheckedItem item = objects.get(position); 
      booleanArray.put(position, isChecked); 
      item.setChecked(isChecked); 
     } 
     notifyDataSetChanged(); 
    } 

    public SparseBooleanArray getBooleanArray() { 
     return booleanArray; 
    } 

    public void changeSelectionForAllItems(boolean isSelected) { 
     for (int i = 0; i < objects.size(); i++) { 
      CheckedItem item = objects.get(i); 
      item.setChecked(isSelected); 
      booleanArray.put(i, isSelected); 
     } 
    } 

    static class ViewHolder { 
     TextView name; 
     CheckBox checkedBox; 
    } 
} 

和列表視圖：

List<CheckedItem> items = new ArrayList<CheckedItem>(); 
     adapter = new DownloadDocsListViewAdapter(getContext(), items); 
     adapter.registerDataSetObserver(new DataSetObserver() { 
      @Override 
      public void onChanged() { 
       SparseBooleanArray sparseArray = adapter.getBooleanArray(); 
       isAtLeastOneElementChecked = false; 
       for(int i = 0; i < sparseArray.size(); i++) { 
        int key = sparseArray.keyAt(i); 
        // get the object by the key. 
        boolean obj = sparseArray.get(key); 
        if (obj == true) { 
         isAtLeastOneElementChecked = true; 
         break; 
        } 
       } 

       getActivity().invalidateOptionsMenu(); 
      } 
     }); 

     listView.setAdapter(adapter); 
     listView.setOnItemClickListener(this); 
     //add the select All checkbox 
     adapter.add(new CheckedItem(getResources().getString(R.string.select_all),getResources().getString(R.string.select_all)));