[C#] Callback Func

예제 1

namespace Cshop_v6._0
{
    delegate int GetResultDelegate();

    class Target
    {
        public void Do(GetResultDelegate getResult)
        {
            Console.WriteLine(getResult()); // 콜백 메서드 호출
        }
    }

    class Source
    {
        public int GetResult() // 콜백 용도로 전달된 메서드
        {
            return 10;
        }

        public void Test()
        {
            Target target = new Target();
            target.Do(new GetResultDelegate(this.GetResult));
        }
    }
}

예제 2

namespace Cshop_v6._0
{
    delegate int GetResultDelegate(int x, int y);

    class Target
    {
        public void Do(GetResultDelegate getResult, int x, int y)
        {
            Console.WriteLine(getResult(x, y));
        }
    }

    class Source
    {
        public static int GetResult(int x, int y)
        {
            return x * y;
        }

        public static void Main()
        {
            Target target = new Target();
            GetResultDelegate gd = GetResult;
            target.Do(gd, 5, 10);
        }
    }
}

[C#] Delegate

접근제한자 delegate 대상_메서드_반환타입 식별자(… … 대상_메서드_매개변수_목록 … …);

예제 1

namespace Cshop_v6._0
{
    public class Mathematics
    {
        delegate int CalcDelegate(int x, int y);

        static int Add(int x, int y)      { return x + y; }
        static int Subtract(int x, int y) { return x - y; }
        static int Multiply(int x, int y) { return x * y; }
        static int Devide(int x, int y)   { return x / y; }

        CalcDelegate[] methods;

        public Mathematics()
        {
            methods = new CalcDelegate[] { Mathematics.Add, Mathematics.Subtract, Mathematics.Multiply, Mathematics.Devide };
        }

        public void Calculate(char opCode, int operand1, int operand2)
        {
            switch (opCode)
            {
                case '+': Console.WriteLine("+: " + methods[0](operand1, operand2)); break;
                case '-': Console.WriteLine("-: " + methods[1](operand1, operand2)); break;
                case '*': Console.WriteLine("*: " + methods[2](operand1, operand2)); break;
                case '/': Console.WriteLine("/: " + methods[3](operand1, operand2)); break;
            }
        }
    }

    class Program
    {
        delegate void WorkDelegate(char arg1, int arg2, int arg3);

        static void Main()
        {
            Mathematics math = new Mathematics();
            WorkDelegate work = math.Calculate;

            work('+', 10, 5);
            work('-', 10, 5);
            work('*', 10, 5);
            work('/', 10, 5);
        }
    }
}

예제 2

namespace Cshop_v6._0
{
    class Program
    {
        delegate void CalcDelegate(int x, int y);

        static void Add(int x, int y) { Console.WriteLine(x + y); }
        static void Subtract(int x, int y) { Console.WriteLine(x - y); }
        static void Multiply(int x, int y) { Console.WriteLine(x * y); }
        static void Divide(int x, int y) { Console.WriteLine(x / y); }

        static void Main()
        {
            CalcDelegate calc = Add;
            calc += Subtract;
            calc += Multiply;
            calc += Divide;

            calc(10, 5);

            // 출력결과
            /*
            15
            5
            50
            2
            */

            Console.WriteLine("=================================================================");

            calc -= Divide;

            calc(10, 5);


            // 출력결과
            /*
            15
            5
            50
            */
        }
    }
}