C# Properties
Properties are named members of classes, structures, and interfaces. Member variables or methods in a class or structure are called Fields. Properties are extensions of Fields and can be accessed using the same syntax. They use accessors to make private field values readable, writable, or manipulated.
Property does not determine the storage location. Instead, they have accessors that can read, write, or compute their values.
For example, there is a class named Student with private fields for age, name, and code. We cannot directly access these fields outside the scope of the class, but we can have properties that access these private fields.
Accessors
Property's AccessorContains information that helps get (read or calculate) or set ( executable statement for writing) properties. An accessor declaration can contain a get accessor, a set accessor, or both. For example:
// 声明类型为 string 的 Code 属性
public string Code
{
get
{
return code;
}
set
{
code = value;
}
}
// 声明类型为 string 的 Name 属性
public string Name
{
get
{
return name;
}
set
{
name = value;
}
}
// 声明类型为 int 的 Age 属性
public int Age
{
get
{
return age;
}
set
{
age = value;
}
}Example
The following example demonstrates the usage of properties:
using System;
namespace tutorialspoint
{
class Student
{
private string code = "N.A";
private string name = "not known";
private int age = 0;
// 声明类型为 string 的 Code 属性
public string Code
{
get
{
return code;
}
set
{
code = value;
}
}
// 声明类型为 string 的 Name 属性
public string Name
{
get
{
return name;
}
set
{
name = value;
}
}
// 声明类型为 int 的 Age 属性
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()
{
// 创建一个新的 Student 对象
Student s = new Student();
// 设置 student 的 code、name 和 age
s.Code = "001";
s.Name = "Zara";
s.Age = 9;
Console.WriteLine("Student Info: {0}", s);
// 增加年龄
s.Age += 1;
Console.WriteLine("Student Info: {0}", s);
Console.ReadKey();
}
}
}When the above code is compiled and executed, it will produce the following results :
Student Info: Code = 001, Name = Zara, Age = 9 Student Info: Code = 001, Name = Zara, Age = 10
Abstract Properties
Abstract classes can have abstract properties, which should be implemented in derived classes. 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;
// 声明类型为 string 的 Code 属性
public string Code
{
get
{
return code;
}
set
{
code = value;
}
}
// 声明类型为 string 的 Name 属性
public override string Name
{
get
{
return name;
}
set
{
name = value;
}
}
// 声明类型为 int 的 Age 属性
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()
{
// 创建一个新的 Student 对象
Student s = new Student();
// 设置 student 的 code、name 和 age
s.Code = "001";
s.Name = "Zara";
s.Age = 9;
Console.WriteLine("Student Info:- {0}", s);
// 增加年龄
s.Age += 1;
Console.WriteLine("Student Info:- {0}", s);
Console.ReadKey();
}
}
}When the above code is compiled and executed, it produces the following results:
Student Info: Code = 001, Name = Zara, Age = 9 Student Info: Code = 001, Name = Zara, Age = 10
