using System;

using System.Threading.Tasks;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        ExicuteBusinessLogic.Run();

    }

}

// Simple Example of Delegate in C#

public delegate void SimapleDelegate(); // A Simple delegate with void return type and no input overload.

public class SimapleDelegateClass

{

    public static void Run()

    {

        SimapleDelegate del = new SimapleDelegate(PrintMessage);// Here we assigned PrintMessage method into SimapleDelegate and exicute using RUN Method inot Program.Main

        del();

    }

    public static void PrintMessage()

    {

        Console.WriteLine($"Hello World");

    }

}

​

//----Passing a delegate a overload in a Method

// Simple Example of Delegate in C#

public delegate decimal EmployeeDelegate(decimal x, decimal y); // A Simple delegate with void return type and no input overload.

public class Employee

{

    public static void Run()

    {

        List<Employee> emplist = new List<Employee>()

        {

            new Employee(){Id=1, EmpType=1, Name="Orbit Rover", Salary =85000},

            new Employee(){Id=2, EmpType=2, Name="Nion Tesla", Salary =95000},

            new Employee(){Id=3, EmpType=3, Name="Bekky Backer", Salary =55000},

        };

        GetEmployeeBonus(emplist, CalculateBonus);

    }

    public static decimal CalculateBonus(decimal per, decimal salary)

    {

        return salary * per / 100;

    }

​

    public static void GetEmployeeBonus(List<Employee> emplist, EmployeeDelegate _bonus)

    {

        foreach(var emp in emplist)

        {

            var bonus=0.0m;

            switch (emp.EmpType)

            {

                    case 1:

                        bonus = _bonus(10, emp.Salary);

                        Console.WriteLine($"Id: {emp.Id}, EmpType: Permanent, Name: {emp.Name}, Salary: {emp.Salary}, Bonus: {bonus}");

                        break;

                    case 2:

                        bonus = _bonus(5, emp.Salary);

                        Console.WriteLine($"Id: {emp.Id}, EmpType: Contract, Name: {emp.Name}, Salary: {emp.Salary}, Bonus: {bonus}");

                        break;

                    case 3:

                        Console.WriteLine($"Id: {emp.Id}, EmpType: Temporary, Name: {emp.Name}, Salary: {emp.Salary}, Bonus: {bonus}");

                        break;

            }

        }

    }

    public int Id {get; set;}

    public int EmpType {get; set;}

    public string Name {get; set;}

    public decimal Salary {get; set;}

}

​

// Above two methos are useless because they don't have any use of delegate we can achive the result directaly from method insted using of delegate.

// The perpouse of use of delegate is code reusability, loose coupling, exicuting method in multithreading taks.

// Next Example is showing how to re-use the code using loose coupling

// Here We can calculate Bonous and Monthaly Salary for each employee using the same delegate, but still delegate looking use-less here because we can still achive current result using methos only?

​

public delegate decimal Employee2Delegate(decimal x, decimal y); // A Simple delegate with void return type and no input overload.

public class Employee2

{

    public static void Run()

    {

        List<Employee> emplist = new List<Employee>()

        {

            new Employee(){Id=1, EmpType=1, Name="Orbit Rover", Salary =85000},

            new Employee(){Id=2, EmpType=2, Name="Nion Tesla", Salary =95000},

            new Employee(){Id=3, EmpType=3, Name="Bekky Backer", Salary =55000},

        };

        GetEmployeeBonus(emplist, CalculateBonus, CalculateMonthalySalary);

    }

    public static decimal CalculateBonus(decimal per, decimal salary)

    {

        return salary * per / 100;

    }

    public static decimal CalculateMonthalySalary(decimal months, decimal salary)

    {

        return salary / months;

    }

    public static void GetEmployeeBonus(List<Employee> emplist, Employee2Delegate _bonus, Employee2Delegate _monthalySalary)

    {

        foreach(var emp in emplist)

        {

            var bonus=0.0m;

            var monthalySalary=0.0m;

            switch (emp.EmpType)

            {

                    case 1:

                        bonus = _bonus(10, emp.Salary);

                        monthalySalary = _monthalySalary(12, emp.Salary);

                        Console.WriteLine($"Id: {emp.Id}, EmpType: Permanent, Name: {emp.Name}, Salary: {emp.Salary}, Bonus: {bonus}, Monthaly Salary {monthalySalary.ToString("#.##")}");

                        break;

                    case 2:

                        bonus = _bonus(5, emp.Salary);

                        monthalySalary = _monthalySalary(9, emp.Salary);

                        Console.WriteLine($"Id: {emp.Id}, EmpType: Contract, Name: {emp.Name}, Salary: {emp.Salary}, Bonus: {bonus}, Monthaly Salary {monthalySalary.ToString("#.##")}");

                        break;

                    case 3:

                        monthalySalary = _monthalySalary(6, emp.Salary);

                        Console.WriteLine($"Id: {emp.Id}, EmpType: Temporary, Name: {emp.Name}, Salary: {emp.Salary}, Bonus: {bonus}, Monthaly Salary {monthalySalary.ToString("#.##")}");

                        break;

            }

        }

    }

    public int Id {get; set;}

    public int EmpType {get; set;}

    public string Name {get; set;}

    public decimal Salary {get; set;}

}

​

public delegate void Operation();

public class ExicuteBusinessLogic

{

    public static void Run()

    {

        Console.WriteLine($"Step 1");

        BusinessLogic _business = new BusinessLogic();

        _business.getSomeDataFromAccess();

    }

}

public class BusinessLogic : BaseBusiness

{

    DataAccessLogic _access = new DataAccessLogic();

    public int getSomeDataFromAccess()

    {

    Console.WriteLine($"Step 2");

        int result=0;

        _operation = () =>

        {

            result = _access.GetSomeData();

        };

        Start(false);

        return result;

    }

}

public class BaseBusiness

{

    protected Operation _operation;

    public bool Start(bool isTransactionRequired)

    {

        Console.WriteLine($"Step 3");

        bool success = false;

        try

        {

            this.ExecuteOperation(isTransactionRequired);

            success = true;

        }

        catch (Exception ex)

        {

            Console.WriteLine($"Exception: {ex.Message}" );

        }

        return (success);

    }

    public virtual void ExecuteOperation(bool isTransactionRequired)

    {

        Console.WriteLine($"Step 4");

        try

        {

            this._operation();

        }

        catch (Exception ex)

        {

            Console.WriteLine($"Exception: {ex.Message} ");

            throw;

        }

    }

}

public class DataAccessLogic

{

    private readonly string _connectionstring;

    public DataAccessLogic()

    {

        _connectionstring = "Your Connection String";

    }

    public int GetSomeData()

    {

        Console.WriteLine($"Step 5");

        ExicuteHelper.ExicuteReader();

        return 1;

    }

}

public class ExicuteHelper

{

    public static void ExicuteReader()

    {

        Console.WriteLine($"Step 6");

        Console.WriteLine("Method Executed Successfully");

    }

}

​