簡單工程模式:簡單工廠模式是由一個工廠對象決定創建出哪一種產品類的實例。簡單工廠模式是工廠模式家族中最簡單實用的模式,可以理解爲是不同工廠模式的一個特殊實現。
使用簡單工程模式實現一個計算器類:
源代碼如下:
// Operation.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Program
{
public class Operation// 此類爲父類
{
private double _numberA = 0; /// 數字A
private double _numberB = 0; /// 數字B
public double NumberA
{
get { return _numberA;}
set {_numberA = value;}
}
public double NumberB
{
get { return _numberB; }
set { _numberB = value; }
}
public virtual double GetResult()
{
double result = 0;
return result;
}
}
}
// ChildOperation.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Program
{
class OperationAdd:Operation
{
public override double GetResult()
{
double result = 0;
result = NumberA + NumberB;
//return result ;
return base.GetResult();
}
}
class OperationSub:Operation
{
public override double GetResult()
{
double result = 0;
result = NumberA - NumberB;
//return result;
return base.GetResult();
}
}
class OperationMul:Operation
{
public override double GetResult()
{
double result = 0;
result = NumberA * NumberB;
return result;
//return base.GetResult();
}
}
class OperationDiv:Operation
{
public override double GetResult()
{
double result = 0;
result = NumberA / NumberB;
return result;
//return base.GetResult();
}
}
}
/// OperationFactory.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Program
{
class OperationFactory
{
public static Operation createOperate(string operate)
{
Operation oper = null;
switch(operate)
{
case "+":
oper = new OperationAdd();
break;
case "-":
oper = new OperationSub();
break;
case "*":
oper = new OperationMul();
break;
case "/":
oper = new OperationDiv();
break;
}
return oper;
}
}
}
///Program.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Program
{
class Program
{
static void Main(string[] args)
{
try
{
Console.Write("請輸入數字A:");
string strNumberA = Console.ReadLine();
Console.Write("請選擇運算符號(+,-,*,/):");
string strOperation = Console.ReadLine();
Console.Write("請輸入數字B:");
string strNumberB = Console.ReadLine();
//string strResult = "";
// strResult = Convert.ToString(Operation.GetResult(Convert.ToDouble(strNumberA), Convert.ToDouble(strNumberB), strOperation));
// Console.WriteLine("結果是:"+strResult);
Operation oper;//
oper = OperationFactory.createOperate(strOperation);
oper.NumberA = Convert.ToDouble(strNumberA);
oper.NumberB = Convert.ToDouble(strNumberB);
double result = oper.GetResult();
Console.Write(result);
}
catch (System.Exception ex)
{
Console.WriteLine("輸入有誤:"+ex.Message);
}
}
}
}
參考資料: 《大話設計模式》
UML工具: StarUML
代碼調試工具:VS2008