Cursor类取出数据

重点是要调用 moveToFirst();

	long id=intent.getLongExtra("id",0);
			Cursor cr =dbh.selectDataById(id);
			//etname.setText(cr.getString(1));
			if(cr != null){
				cr.moveToFirst();
			}
			etname.setText(cr.getString(cr.getColumnIndex("name")));

另外，在使用ContextMenu的时候，如何获取数据库对应的_id呢

AdapterView.AdapterContextMenuInfo info = (AdapterView.AdapterContextMenuInfo) item
		.getMenuInfo();
    	dbh.deleteData(info.id);