Operation opt = OperatorFactory.CreateOperator(this.cboOperator.Text, double.Parse(this.txtNum1.Text), double.Parse(this.txtNum2.Text));//多态1
this.txtResult.Text = opt.DoOperate().ToString();
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace 多态实现计算器
{
class operationFo
{
public static Operation CreateOperator(string type,int a,int b)//多态1
{
Operation opt=null;
