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5-6 Generic Delegates in C#

发布时间 2023-06-26 11:56:30作者: katesharing

1. What are Generic Delegates in C#?

2. Types of Generic Delegates in C#.

3. Why do we need the Generic Delegates?

 用delegate的完整写法如下：

using System;
namespace GenericDelegatesDemo
{
    public class GenericDelegates
    {
        public delegate double AddNumber1Delegate(int no1, float no2, double no3);
        public delegate void AddNumber2Delegate(int no1, float no2, double no3);
        public delegate bool CheckLengthDelegate(string name);

        static void Main(string[] args)
        {
            AddNumber1Delegate obj1 = new AddNumber1Delegate(AddNumber1);
            double Result = obj1.Invoke(100, 125.45f, 456.789);
            Console.WriteLine(Result);

            AddNumber2Delegate obj2 = new AddNumber2Delegate(AddNumber2);
            obj2.Invoke(50, 255.45f, 123.456);

            CheckLengthDelegate obj3 = new CheckLengthDelegate(CheckLength);
            bool Status = obj3.Invoke("Pranaya");
            Console.WriteLine(Status);

            Console.ReadKey();
        }

        public static double AddNumber1(int no1, float no2, double no3)
        {
            return no1 + no2 + no3;
        }

        public static void AddNumber2(int no1, float no2, double no3)
        {
            Console.WriteLine(no1 + no2 + no3);
        }

        public static bool CheckLength(string name)
        {
            if (name.Length > 5)
                return true;
            return false;
        }
    }
}
View Code

4. Func Generic Delegate in C#?

4.1 What is Func Generic Delegate in C#?

4.2 How to use Func Generic Delegate in C#?

5. Action Generic Delegate in C#?

5.1 What is Action Generic Delegate in C#?

5.2 How to use Action Generic Delegate in C#?

6. Predicate Generic Delegate in C#?

6.1 What is Predicate Generic Delegate in C#?

6.2 How to use Predicate Generic Delegate in C#?

7. Examples to understand Generic Delegates in C#.

完整例子如下所示：

using System;
namespace GenericDelegateDemo
{
    public class GenericDelegates
    {
        static void Main(string[] args)
        {
            Func<int, float, double, double> obj1 = new Func<int, float, double, double>(AddNumber1);
            double Result = obj1.Invoke(100, 125.45f, 456.789);
            Console.WriteLine(Result);

            Action<int, float, double> obj2 = new Action<int, float, double>(AddNumber2);
            obj2.Invoke(50, 255.45f, 123.456);

            Predicate<string> obj3 = new Predicate<string>(CheckLength);
            bool Status = obj3.Invoke("Pranaya");
            Console.WriteLine(Status);

            Console.ReadKey();
        }

        public static double AddNumber1(int no1, float no2, double no3)
        {
            return no1 + no2 + no3;
        }

        public static void AddNumber2(int no1, float no2, double no3)
        {
            Console.WriteLine(no1 + no2 + no3);
        }

        public static bool CheckLength(string name)
        {
            if (name.Length > 5)
                return true;
            return false;
        }
    }
}
View Code

8. Generic Delegates with Lambda Expression in C#

using System;
namespace GenericDelegateDemo
{
    public class GenericDelegates
    {
        static void Main(string[] args)
        {
            Func<int, float, double, double> obj1 = (x, y, z) =>
            {
                return x + y + z;
            };

            double Result = obj1.Invoke(100, 125.45f, 456.789);
            Console.WriteLine(Result);

            Action<int, float, double> obj2 = (x, y, z) =>
            {
                Console.WriteLine(x + y + z);
            };
            obj2.Invoke(50, 255.45f, 123.456);

            Predicate<string> obj3 = new Predicate<string>(CheckLength);
            bool Status = obj3.Invoke("Pranaya");
            Console.WriteLine(Status);

            Console.ReadKey();
        }
        public static bool CheckLength(string name)
        {
            if (name.Length > 5)
                return true;
            return false;
        }
    }
}
View Code
using System;
namespace GenericDelegateDemo
{
    public class GenericDelegates
    {
        static void Main(string[] args)
        {
            Func<int, float, double, double> obj1 = (x, y, z) =>
            {
                return x + y + z;
            };

            double Result = obj1.Invoke(100, 125.45f, 456.789);
            Console.WriteLine(Result);

            Action<int, float, double> obj2 = (x, y, z) =>
            {
                Console.WriteLine(x + y + z);
            };
            obj2.Invoke(50, 255.45f, 123.456);

            Predicate<string> obj3 = new Predicate<string>(CheckLength);
            bool Status = obj3.Invoke("Pranaya");
            Console.WriteLine(Status);

            Console.ReadKey();
        }
        public static bool CheckLength(string name)
        {
            if (name.Length > 5)
                return true;
            return false;
        }
    }
}

 9. Points to Remember while working with C# Generic Delegates: