C# 委托、事件、特性程序

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委托和事件

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public partial class Form1 : Form
{
   public Form1()
   {
       InitializeComponent();

Man man = new Man("小明");

       Roommate[] roommates = {
           new Roommate("小张"),
           new Roommate("小朱"),
           new Roommate("小李"),
       };

       man.action += roommates[0].TakeFood;
       man.action += roommates[1].TakePakage;
       man.action += roommates[2].TakePakage;
       man.action += roommates[2].TakeFood;

man.Down();
}
}

public class Man
{
public string Name { get; private set; }

public event Action action = null;

   public Man(string name)
   {
       Name = name;
   }

   public void Down()
   {
       MessageBox.Show(Name + "下楼了");
       if (action != null)
       {
           action();
       }
   }
}

public class Roommate
{
public string Name { get; private set; }

   public Roommate(string name)
   {
       Name = name;
   }

   public void TakePakage()
   {
       MessageBox.Show(Name + "取包裹。");
   }

   public void TakeFood()
   {
       MessageBox.Show(Name + "取食物。");
   }
}

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特性

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[AttributeUsage(AttributeTargets.Class)]
public sealed class InformationAttribute : Attribute
{
   public string developer;
   public string version;
   public string description;

   public InformationAttribute(string developer, string version, string description)
   {
       this.developer = developer;
       this.version = version;
       this.description = description;
   }
}

[Information("张三","v1.0","测试类1")]
public class TestClass1
{

}

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泛型委托

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public partial class Form1 : Form
{
   public Form1()
   {
       InitializeComponent();

       Employee[] employees = {
           new Employee("a",600),
           new Employee("b",100),
           new Employee("c",300),
           new Employee("d",800),
           new Employee("e",200),
       };

Sort<Employee>(employees, Employee.Compare);

       string str="";
       foreach (Employee emp in employees)
       {
           str = str + emp.Name+ "--" + emp.Salary +"\n";
       }
       MessageBox.Show(str);
   }

   public static void Sort<T>(T[] data, Func<T, T, bool> compare)
   {
       bool falg = true;
       do
       {
           falg = false;
           for (int i = 0; i < data.Length-1; i++)
           {
               if (compare(data[i], data[i + 1]))
               {
                   T temp = data[i];
                   data[i] = data[i + 1];
                   data[i + 1] = temp;
                   falg = true;
               }
           }
       } while (falg);
   }
}