c# - 使用 .net 2.0 进行分组你是怎么做到的？

Question

在 .net 2.0 项目上工作，没有 linq，也不能添加任何外部库。

构建一个小示例，说明我在实际项目中需要做什么。

如何在不使用 linq 的情况下按“Employee.Category”分组。

我需要为每个小组做一些事情。

在 .net 2.0 中如何分组？

     class Program
        {
            static void Main(string[] args)
            {
                List<Employee>employees=new List<Employee>();
                Employee employee = new Employee();
                employee.Id = 1;
                employee.Category = "Management";

                Employee employee2 = new Employee();
                employee.Id = 2;
                employee.Category = "Management";

                Employee employee3 = new Employee();
                employee.Id = 3;
                employee.Category = "Director";

                Employee employee4 = new Employee();
                employee.Id = 4;
                employee.Category = "Worker";

                Employee employee5= new Employee();
                employee.Id = 5;
                employee.Category = "Director";
                Employee employee6 = new Employee();
                employee.Id = 6;
                employee.Category = "Worker";

                employees.AddRange(new Employee[] { employee, employee2, employee3, employee4, employee5, employee6 });

                //1)Group them by category in .net 2.O NO LINQ
                //2)Foreach item in the group do something.

                Console.WriteLine("??");
            }
        }

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

谢谢你的建议

Answer 1

怎么样:

Dictionary<string, List<Employee>> groups =
       new Dictionary<string, List<Employee>>();
foreach(Employee emp in employees) {
    List<Employee> group;
    if(!groups.TryGetValue(emp.Category, out group)) {
        group = new List<Employee>();
        groups.Add(emp.Category, group);
    }
    group.Add(emp);
}

foreach(KeyValuePair<string,List<Employee>> pair in groups) {
    Console.WriteLine(pair.Key);
    foreach(Employee emp in pair.Value) {
        Console.WriteLine(emp.Id);
    }
}