net基础

看题，然后写出输出结果：（2.0的framework没法自动化属性）

using System;
using System.Collections.Generic;
using System.Text;

namespace ConsoleApplication13
{

    public abstract class A
    {
        private string _name;
        public string Name { get { return _name; } set { value = this._name; } }

        private int a = 12;
        public A()
        {
            Console.WriteLine("A");
        }
        public virtual void Fun()
        {
            Console.WriteLine("A.Fun()");
        }

    }
    public class B : A
    {
        public int _age;
        public int age { get { return _age; } set { value = this._age; } }

        public int c = 12;

        public B()
        {
            Console.WriteLine("B");
        }
        public new void Fun()
        {
            Console.WriteLine("B.Fun()");
        }

    }

    class Program
    {
        static void Main(string[] args)
        {
            //当有继承再的时候，先实例调用父类中的
            //1.先初始化本类中的字段
            //2.接着初始化父类中的字段
            //3.调用父类中的构造函数进行属性的初始化
            //4.最后调用本类中的构造函数进行属性的初始化
            //所以结果是：
            //A
            //B
            //A.Fun()

            A a = new B();//子类实例化父类； 

            a.Fun(); 

            Console.ReadLine();

        }
    }
}

变形一：

using System;
using System.Collections.Generic;
using System.Text;

namespace ConsoleApplication13
{

    public abstract class A
    {
        private string _name;
        public string Name { get { return _name; } set { value = this._name; } }

        private int a = 12;
        public A()
        {
            Console.WriteLine("A");
        }
        public virtual void Fun()
        {
            Console.WriteLine("A.Fun()");
        }

    }
    public class B : A
    {
        public int _age;
        public int age { get { return _age; } set { value = this._age; } }

        public int c = 12;

        public B()
        {
            Console.WriteLine("B");
        }
        public override void Fun()
        {
            Console.WriteLine("B.Fun()");
        }

    }

    class Program
    {
        static void Main(string[] args)
        {

            //结果是：
            //A
            //B
            //B.Fun()

            A a = new B();//子类实例化父类； 

            a.Fun(); 

            Console.ReadLine();

        }
    }
}

变形二：

using System;
using System.Collections.Generic;
using System.Text;

namespace ConsoleApplication13
{

    public abstract class A
    {
        private string _name;
        public string Name { get { return _name; } set { value = this._name; } }

        private int a = 12;
        public A()
        {
            Console.WriteLine("A");
        }
        public virtual void Fun()
        {
            Console.WriteLine("A.Fun()");
        }

    }
    public class B : A
    {
        public int _age;
        public int age { get { return _age; } set { value = this._age; } }

        public int c = 12;

        public B()
        {
            Console.WriteLine("B");
        }
        public new void Fun()
        {
            Console.WriteLine("B.Fun()");
        }

    }

    class Program
    {
        static void Main(string[] args)
        {

            //结果是：
            //A
            //B
            //B.Fun()

            B b = new B();//实例化子类；

            b.Fun(); 

            Console.ReadLine();

        }
    }
}

总结：

  public class father
    {
        public void normalFun()
        {
            Console.WriteLine("f-normal");

        }

        public virtual void virFun()
        {
            Console.WriteLine("f-virtual");

        }

    }

    public class son : father
    {
        public new void normalFun()
        {
            Console.WriteLine("s-normal");
        }

        public override void virFun()
        {
            Console.WriteLine("s-virtual");
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            father f = new son();

            f.normalFun(); //f-normal
            f.virFun(); // s-virtual

            //记住：
            //new     的本质是：覆盖.隐藏 父类中的方法。
            //ovrride 的本质是：对父类中方法的扩展；

            Console.ReadLine();

        }
    }

然后接着：我们再来看一道题：

 public class A
    {
        public virtual void Fun1(int i)
        {
            Console.WriteLine(i);
        }
        public void Fun2(A a)
        {
            a.Fun1(1);
            Fun1(5);
        }
    }
    public class B : A
    {
        public override void Fun1(int i)
        {
            base.Fun1(i + 1);
        }
        public static void Main()
        {
            B b = new B();
            A a = new A();
            a.Fun2(b);  //2 5
            b.Fun2(a);  //1 6
            Console.ReadLine();
        }
    }