C#学习：事件

￡神魔★判官ぃ 2021-12-23 09:57 226阅读 0赞

类或对象可以通过事件向其他类或对象通知发生的相关事情。 发送（或引发）事件的类称为“发行者”，接收（或处理）事件的类称为“订阅者”。

*  **一个简单事件实例**
    
        //发行者
            public class Student
            {
                private string name;
        
                //定义一个带参委托
                public delegate void DelegateRegisterFinish(string name);
                //定义一个事件
                public event DelegateRegisterFinish EventRegisterFinish;
        
                public Student(string name)
                {
                    this.name = name;
                }
        
                //在一定条件下，发行者发布事件
                public void Register()
                {
                    Console.WriteLine("学生{0}进行注册", name);
                    if (EventRegisterFinish != null)
                        EventRegisterFinish(name);
                }
            }
    
        //订阅者
            class RegisterStudent
            {
                static void Main(string[] args)
                {
                    Console.WriteLine("输入学生姓名：");
                    string studentName = Console.ReadLine();
                    Console.WriteLine("--------------------------------------");
        
                    Student student = new Student(studentName);
        
                    //为静态方法student_EventRegisterFinishOne订阅事件
                    //C#1.0语法
                    student.EventRegisterFinish += new
                        Student.DelegateRegisterFinish(student_EventRegisterFinishOne);
                    //C#2.0语法
                    //student.EventRegisterFinish += student_EventRegisterFinishOne;
        
                    //为RegisterStudent实例对象的student_EventRegisterFinishTwo方法订阅事件
                    //本处其实利用多路广播委托为多个方法订阅事件
                    RegisterStudent rs = new RegisterStudent();
                    student.EventRegisterFinish += rs
                        .student_EventRegisterFinishTwo;
        
                    //发行者发布事件后订阅者做相应的操作
                    student.Register();
        
                    Console.WriteLine("--------------------------------------");
                    //取消订阅
                    student.EventRegisterFinish -= rs
                        .student_EventRegisterFinishTwo;
                    student.Register();
        
                    Console.Read();
                }
                private static void student_EventRegisterFinishOne(string name)
                {
                    Console.WriteLine("{0}注册成功", name);
                }
                private void student_EventRegisterFinishTwo(string name)
                {
                    Console.WriteLine("{0}请及时领取住宿用品", name);
                }
            }
    
    结果：
    
    ![2012061223364957.jpg][]

转载于:https://www.cnblogs.com/wanghonghu/archive/2012/06/12/2547045.html

[2012061223364957.jpg]: /images/20211223/9ef2c04e71f94eb589eb55e368ff395a.png