using?System;
using?System.Collections.Generic;
using?System.Text;

namespace?工廠方法_計算器
{

????///?

????///?運算類
????///?

????class?Operation
????{
????????private?double?_numberA?=?0;
????????private?double?_numberB?=?0;

????????public?double?NumberA
????????{
????????????get?{?return?_numberA;?}
????????????set?{?_numberA?=?value;?}
????????}

????????public?double?NumberB
????????{
????????????get?{?return?_numberB;?}
????????????set?{?_numberB?=?value;?}
????????}

????????///?

????????///?得到運算結果
????????///?

????????///?
????????public?virtual?double?GetResult（）
????????{
????????????double?result?=?0;
????????????return?result;
????????}
????}

????///?

????///?加法類
????///?