Csharp 简明教程

C

Properties 是类、结构和接口的已命名成员。类或结构中的成员变量或方法称为 Fields 。属性是字段的扩展，并使用相同的语法访问。它们使用 accessors ，可以通过它来读取、写入或操作私有字段的值。

Properties are named members of classes, structures, and interfaces. Member variables or methods in a class or structures are called Fields. Properties are an extension of fields and are accessed using the same syntax. They use accessors through which the values of the private fields can be read, written or manipulated.

属性不命名存储位置。相反，它们有 accessors 来读取、写入或计算它们的值。

Properties do not name the storage locations. Instead, they have accessors that read, write, or compute their values.

例如，让我们有一个名为 Student 的类，其中有 age、name 和 code 的私有字段。我们不能直接从类范围之外访问这些字段，但我们可以有属性来访问这些私有字段。

For example, let us have a class named Student, with private fields for age, name, and code. We cannot directly access these fields from outside the class scope, but we can have properties for accessing these private fields.

Accessors

属性的 accessor 包含可帮助获取（读取或计算）或设置（写入）属性的可执行语句。访问器声明可以包含一个获取访问器、一个设置访问器或两者。例如 −

The accessor of a property contains the executable statements that helps in getting (reading or computing) or setting (writing) the property. The accessor declarations can contain a get accessor, a set accessor, or both. For example −

// Declare a Code property of type string:
public string Code {
   get {
      return code;
   }
   set {
      code = value;
   }
}

// Declare a Name property of type string:
public string Name {
   get {
      return name;
   }
   set {
      name = value;
   }
}

// Declare a Age property of type int:
public int Age {
   get {
      return age;
   }
   set {
      age = value;
   }
}

Example

以下示例演示了属性的用法 −

The following example demonstrates use of properties −

using System;
namespace tutorialspoint {
   class Student {
      private string code = "N.A";
      private string name = "not known";
      private int age = 0;

      // Declare a Code property of type string:
      public string Code {
         get {
            return code;
         }
         set {
            code = value;
         }
      }

      // Declare a Name property of type string:
      public string Name {
         get {
            return name;
         }
         set {
            name = value;
         }
      }

      // Declare a Age property of type int:
      public int Age {
         get {
            return age;
         }
         set {
            age = value;
         }
      }
      public override string ToString() {
         return "Code = " + Code +", Name = " + Name + ", Age = " + Age;
      }
   }

   class ExampleDemo {
      public static void Main() {

         // Create a new Student object:
         Student s = new Student();

         // Setting code, name and the age of the student
         s.Code = "001";
         s.Name = "Zara";
         s.Age = 9;
         Console.WriteLine("Student Info: {0}", s);

         //let us increase age
         s.Age += 1;
         Console.WriteLine("Student Info: {0}", s);
         Console.ReadKey();
      }
   }
}

编译并执行上述代码后，将产生以下结果 −

When the above code is compiled and executed, it produces the following result −

Student Info: Code = 001, Name = Zara, Age = 9
Student Info: Code = 001, Name = Zara, Age = 10

Abstract Properties

一个抽象类可能有一个抽象属性，该属性应在派生类中实现。以下程序对此进行了说明 −

An abstract class may have an abstract property, which should be implemented in the derived class. The following program illustrates this −

using System;

namespace tutorialspoint {
   public abstract class Person {
      public abstract string Name {
         get;
         set;
      }
      public abstract int Age {
         get;
         set;
      }
   }
   class Student : Person {
      private string code = "N.A";
      private string name = "N.A";
      private int age = 0;

      // Declare a Code property of type string:
      public string Code {
         get {
            return code;
         }
         set {
            code = value;
         }
      }

      // Declare a Name property of type string:
      public override string Name {
         get {
            return name;
         }
         set {
            name = value;
         }
      }

      // Declare a Age property of type int:
      public override int Age {
         get {
            return age;
         }
         set {
            age = value;
         }
      }
      public override string ToString() {
         return "Code = " + Code +", Name = " + Name + ", Age = " + Age;
      }
   }

   class ExampleDemo {
      public static void Main() {
         // Create a new Student object:
         Student s = new Student();

         // Setting code, name and the age of the student
         s.Code = "001";
         s.Name = "Zara";
         s.Age = 9;
         Console.WriteLine("Student Info:- {0}", s);

         //let us increase age
         s.Age += 1;
         Console.WriteLine("Student Info:- {0}", s);
         Console.ReadKey();
      }
   }
}

编译并执行上述代码后，将产生以下结果 −

When the above code is compiled and executed, it produces the following result −

Student Info: Code = 001, Name = Zara, Age = 9
Student Info: Code = 001, Name = Zara, Age = 10