004 C# 结构体Struct

 

C# 结构体（Struct）
在 C# 中，结构体是值类型数据结构。它使得一个单一变量可以存储各种数据类型的相关数据。struct 关键字用于创建结构体。

例：

struct Books
{
   public string title;
   public string author;
   public string subject;
   public int book_id;
};  

      Books Book1;        /* 声明 Book1，类型为 Books */
      Books Book2;        /* 声明 Book2，类型为 Books */

      /* book 1 详述 */
      Book1.title = "C Programming";
      Book1.author = "Nuha Ali"; 
      Book1.subject = "C Programming Tutorial";
      Book1.book_id = 6495407;

      /* book 2 详述 */
      Book2.title = "Telecom Billing";
      Book2.author = "Zara Ali";
      Book2.subject =  "Telecom Billing Tutorial";
      Book2.book_id = 6495700;

 

Notes:
1. C#的结构体，不支持以整个对象形式来赋值（初始化）。而必须对每一项结构体属性单独赋值。

2. 但是，可以通过“构造函数”来初始化结构体变量的值。但是需要对所有变量都赋值（不能有遗漏）。

enum Day { Sun, Mon, Tue, Wed, Thu, Fri, Sat };

     struct Person
     {
        public string name;
        public int age;
        public Day workingday;
        public Person(string name, int age)
        {
            this.name = name;        // 赋值name
            this.age = age;        // 赋值age
            this.workingday = Day.Mon;    //赋值workingday
        }
        public void PrintInfo()
        {
            Console.WriteLine("Name: {0}\nAge: {1}\nWorkingday: {2}", this.name, this.age, this.workingday);
        }
     };

 

3. 在使用new来生成一个结构体实例时，会自动调用“构造方法”

Person p1 = new Person("haha", 36);
p1.PrintInfo();

 

输出：
Name: haha
Age: 36
Workingday: Mon

4. 结构体，可以有常量const和静态static字段

 enum Day { Sun, Mon, Tue, Wed, Thu, Fri, Sat };

        struct Person
        {
            public string name;
            public int age;
            public Day workingday;
            const int holidays = 10;    　　 // 常量“holidays”
            public static int count = 0;    // 静态属性“count”
            public Person(string name, int age)
            {
                this.name = name;
                this.age = age;
                this.workingday = Day.Mon;
                Person.count++;
            }
            public void PrintInfo()
            {
                Console.WriteLine("Name: {0}\nAge: {1}\nWorkingday: {2}\nholidays: {3}", this.name, this.age, this.workingday, holidays);
// 这里调用常量，不需要加this.
            }
        };

            Console.WriteLine("生成的人数： {0}", Person.count);