设计模式之—简单工厂模式<Simple Factory Pattern >

简单工厂模式结构图：

简单工厂模式以简单的加减乘除运算为例：

运算符类（Operation）：

namespace CalcTest.Simple_Factory_patterns
{
    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; }
        }

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

View Code

加法类（Add）：继承于运算符类（Operation）

 1 namespace CalcTest.Simple_Factory_patterns
 2 {
 3     class Add :Operation
 4     {
 5         public override double GetResult()
 6         {
 7             return NumberA + NumberB;
 8         }
 9     }
10 }

View Code

减法类（Subtraction）：继承于运算符类（Operation）

 1 namespace CalcTest.Simple_Factory_patterns
 2 {
 3     class Subtraction : Operation
 4     {
 5         public override double GetResult()
 6         {
 7             return NumberA - NumberB;
 8         }
 9     }
10 }

View Code

乘法类（Multiplacation）：继承于运算符类（Operation）

 1 namespace CalcTest.Simple_Factory_patterns
 2 {
 3     class Multiplication : Operation
 4     {
 5         public override double GetResult()
 6         {
 7             return NumberA * NumberB;
 8         }
 9     }
10 }

View Code

除法类（Division）：继承于运算符类（Operation）

 1 namespace CalcTest.Simple_Factory_patterns
 2 {
 3     class Division : Operation
 4     {
 5         public override double GetResult()
 6         {
 7             if (NumberB == 0)
 8             {
 9                 throw new Exception("除数不能为0");
10             }
11             return NumberA / NumberB;
12         }
13     }
14 }

View Code

运算符工厂类（OperationFactory）：实例合适的对象，通过多态返回父类的方式实现计算结果

 1 namespace CalcTest.Simple_Factory_patterns
 2 {
 3     class OperationFactory
 4     {
 5         public static Operation createOperation(string operate)
 6         {
 7             Operation oper = null;
 8             switch (operate)
 9             {
10                 case "+":
11                     oper = new Add();
12                     break;
13                 case "-":
14                     oper = new Subtraction();
15                     break;
16                 case "*":
17                     oper = new Multiplication();
18                     break;
19                 case "/":
20                     oper = new Division();
21                     break;
22             }
23             return oper;
24         }
25     }
26 }

View Code

测试类（Main）：

 1 namespace CalcTest.Simple_Factory_patterns
 2 {
 3     class TestMain
 4     {
 5         public static void Main(string[] args)
 6         {
 7             Operation oper = null;
 8             //先输入操作符利用简单工厂模式创建类
 9             Console.Write("请输入操作符：(+、-、*、/)");
10             string operate = Console.ReadLine();
11             oper = OperationFactory.createOperation(operate);
12 
13             Console.Write("请输入数字A：");
14             oper.NumberA = Convert.ToDouble(Console.ReadLine());
15 
16             Console.Write("请输入数字B：");
17             oper.NumberB = Convert.ToDouble(Console.ReadLine());
18             double result = oper.GetResult();
19             Console.WriteLine("结果为：" + result);
20             Console.ReadLine();
21         }
22     }
23 }

View Code

简单工厂模式操作结束！

要么忍，要么狠，要么滚！