在這個案例中，我們將使用C#的Dictionary集合（它是一個鍵值對集合，類似于其他編程語言中的Map）來存儲員工的ID和他們的薪水。我們將創建一個簡單的控制臺應用程序，用于添加員工、顯示員工薪水以及更新員工薪水。

首先，我們需要創建一個Employee類來存儲員工的信息：

public class Employee
{
    public int Id { get; set; }
    public string Name { get; set; }
    public decimal Salary { get; set; }
}

接下來，我們將創建一個EmployeeManager類來處理員工的添加、顯示和更新操作：

using System;
using System.Collections.Generic;

public class EmployeeManager
{
    private Dictionary<int, Employee> _employees = new Dictionary<int, Employee>();

    public void AddEmployee(Employee employee)
    {
        if (!_employees.ContainsKey(employee.Id))
        {
            _employees.Add(employee.Id, employee);
        }
        else
        {
            Console.WriteLine("Employee with this ID already exists.");
        }
    }

    public void DisplayEmployeeSalary(int employeeId)
    {
        if (_employees.ContainsKey(employeeId))
        {
            Employee employee = _employees[employeeId];
            Console.WriteLine($"Employee {employee.Name} has a salary of {employee.Salary}.");
        }
        else
        {
            Console.WriteLine("Employee not found.");
        }
    }

    public void UpdateEmployeeSalary(int employeeId, decimal newSalary)
    {
        if (_employees.ContainsKey(employeeId))
        {
            Employee employee = _employees[employeeId];
            employee.Salary = newSalary;
            Console.WriteLine($"Employee {employee.Name}'s salary has been updated to {employee.Salary}.");
        }
        else
        {
            Console.WriteLine("Employee not found.");
        }
    }
}

最后，我們將在Main方法中使用EmployeeManager類來處理用戶輸入：

using System;

class Program
{
    static void Main(string[] args)
    {
        EmployeeManager manager = new EmployeeManager();

        while (true)
        {
            Console.WriteLine("1. Add Employee");
            Console.WriteLine("2. Display Employee Salary");
            Console.WriteLine("3. Update Employee Salary");
            Console.WriteLine("4. Exit");
            Console.Write("Enter your choice: ");
            int choice = Convert.ToInt32(Console.ReadLine());

            switch (choice)
            {
                case 1:
                    Console.Write("Enter employee ID: ");
                    int id = Convert.ToInt32(Console.ReadLine());
                    Console.Write("Enter employee name: ");
                    string name = Console.ReadLine();
                    Console.Write("Enter employee salary: ");
                    decimal salary = Convert.ToDecimal(Console.ReadLine());

                    Employee employee = new Employee { Id = id, Name = name, Salary = salary };
                    manager.AddEmployee(employee);
                    break;

                case 2:
                    Console.Write("Enter employee ID: ");
                    int displayId = Convert.ToInt32(Console.ReadLine());
                    manager.DisplayEmployeeSalary(displayId);
                    break;

                case 3:
                    Console.Write("Enter employee ID: ");
                    int updateId = Convert.ToInt32(Console.ReadLine());
                    Console.Write("Enter new salary: ");
                    decimal newSalary = Convert.ToDecimal(Console.ReadLine());
                    manager.UpdateEmployeeSalary(updateId, newSalary);
                    break;

                case 4:
                    Environment.Exit(0);
                    break;

                default:
                    Console.WriteLine("Invalid choice. Please try again.");
                    break;
            }
        }
    }
}

現在，當你運行這個程序時，你可以添加員工、顯示員工薪水以及更新員工薪水。這個簡單的例子展示了如何使用C#的Dictionary集合（類似于其他編程語言中的Map）來解決實際應用問題。