属性是类,结构和接口的命名成员.一个或多个类中的成员变量或方法称为 Fields .属性是字段的扩展,可以使用相同的语法进行访问.他们使用访问者,通过它们可以读取,写入或操纵私有字段的值.
属性不命名存储位置.相反,他们有访问者来读取,写入或计算他们的值.
例如,让我们有一个名为Student的类,其中包含年龄的私有字段,名称和代码.我们无法直接从类范围外访问这些字段,但我们可以拥有访问这些私有字段的属性.
属性的存取器包含有助于获取(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get访问器,set访问器或两者.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; } }
以下示例演示如何使用属性 :
using System; namespace IT屋 { 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时,会产生以下结果 :
Student Info: Code = 001, Name = Zara, Age = 9 Student Info: Code = 001, Name = Zara, Age = 10
抽象类可能有一个抽象属性,应该在派生类中实现.以下程序说明了这个 :
using System; namespace IT屋 { 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时,会产生以下结果 :
Student Info: Code = 001, Name = Zara, Age = 9 Student Info: Code = 001, Name = Zara, Age = 10