属性是类，结构和接口的成员名称。成员变量或者类中的方法或结构被称为字段。属性字段的扩展，并且使用相同的语法来访问。它们通过使用其私有字段的值可以读取，写入或操纵访问。

属性不命名的存储位置。相反，它们访问的读，写，或计算它们的值。

例如，我们有一个名为Student类，使用年龄，姓名和代码私有字段。从外部类的范围我们无法直接访问这些字段，但我们可以对访问这些private字段属性。

访问器

属性的访问器包含了可执行语句，有助于获得(阅读或计算)或设置(写)属性。在访问声明可以包含一个get访问，set访问，或两者兼而有之。例如：

// 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;
   }
}

例子：

下面的例子演示了属性的使用：

using System;
namespace yiibai
{
   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();
       }
   }
}

当上述代码被编译和执行时，它产生了以下结果：

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

抽象属性

一个抽象类可以具有一个抽象属性，它应该在派生类来实现。下面的程序说明了这一点：

using System;
namespace yiibai
{
   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();
       }
   }
}

让我们编译和运行上面的程序，这将产生以下结果：

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