SQLiteDatabase如何在SQLiteDatabase查询和SimpleCursorAdapter中连接两个字符串？

Question

表字段：

_id，街道，house_nr

查询：

mDb.query(DATABASE_TABLE, new String[] {KEY_ROWID, KEY_STREET_NAME, 
       KEY_HOUSE_NUMBER}, null, null, null, null, KEY_ROWID + " DESC"); 

SimpleCursorAdapter：

Cursor c = mDbHelper.fetchAllRows(); 
    startManagingCursor(c); 

    String[] from = new String[] { HistoryDbAdapter.KEY_STREET_NAME}; 
    int[] to = new int[] { R.id.text1 }; 

    SimpleCursorAdapter entries = 
     new SimpleCursorAdapter(this, R.layout.history_row, c, from, to); 
    setListAdapter(entries); 

如何添加一个组合字符串从两个数据库字段转换为R.id.text1以显示完整地址。

例如：

street = "Android street" 
house_nr = "911" 

则：

R.id.text1 = "Android street 911" 

感谢

Answer 1

有两种方式：

• Concat查询中的两个列名：KEY_STREET_NAME +“|| “+ KEY_HOUSE_NUMBER我会用一个rawQuery然后

• 使用自定义适配器

Answer 2

它的工作原理：。

public class HistoryCursorAdapter extends SimpleCursorAdapter { 
    private final LayoutInflater mInflater; 

    public HistoryCursorAdapter(Context context, int layout, Cursor c, 
      String[] from, int[] to) { 
     super(context, layout, c, from, to); 

     mInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
    } 
    @Override 
    public View getView (int position, View convertView, ViewGroup parent) { 
     ViewHolder holder; 
     if (convertView == null) { 
      convertView = mInflater.inflate(R.layout.history_row, null); 

      holder = new ViewHolder(); 
      holder.text = (TextView) convertView.findViewById(R.id.text1); 

      convertView.setTag(holder); 
     } else { 
      holder = (ViewHolder) convertView.getTag(); 
     } 
     Cursor c = getCursor(); 
     c.moveToPosition(position); 
     int street_index = c.getColumnIndex(HistoryDbAdapter.KEY_STREET_NAME); 
     int house_nr_index = c.getColumnIndex(HistoryDbAdapter.KEY_HOUSE_NUMBER); 
     holder.text.setText(String.format("%s %s", c.getString(street_index), c.getString(house_nr_index))); 
     return convertView; 

    } 

    static class ViewHolder { 
     TextView text; 
    } 
} 

那是我第一次也许可以所著更加简单。 ？也许任何速度的建议