今天发现C#虚函数简直妙不可言....

usingSystem;
usingSystem.Collections.Generic;
usingSystem.Text;

namespaceConsoleApplication2
{
classProgram
{
staticvoidMain(string[]args)
{
//Aa=newA();
//Bb=newB();
Cc=newC();
//b.GetYear();
}
}

publicclassA
{
publicA()
{
Console.WriteLine("DEBUG:Aconstructing");

this.GetYear();
}

publicvirtualvoidGetYear()
{
Console.WriteLine("A");
}
}

publicclassB:A
{
publicB():base()
{
Console.WriteLine("DEBUG:Bconstructing");
this.GetYear();
}

publicoverridevoidGetYear()
{
//base.GetYear();
Console.WriteLine("B");
}
}

publicclassC:B
{
publicC()
{
Console.WriteLine("DEBUG:Cconstructing");
this.GetYear();
}

publicoverridevoidGetYear()
{
//base.GetYear();
Console.WriteLine("C");
}

}


}

运行结果:一定大出你的意料吧!

如果把代码改一下:

usingSystem;
usingSystem.Collections.Generic;
usingSystem.Text;

namespaceConsoleApplication2
...{
classProgram
...{
staticvoidMain(string[]args)
...{
//Aa=newA();
Cc=newC();

//c.GetYear();
//b.GetYear();
}
}

publicclassA
...{
publicA()
...{
Console.WriteLine("DEBUG:Aconstructing");
this.GetYear();
}

protectedvoidGetYear()
...{
Console.WriteLine("A");
}
}

publicclassB:A
...{
publicB():base()
...{
Console.WriteLine("DEBUG:Bconstructing");
this.GetYear();
}

protectedvoidGetYear()
...{
//base.GetYear();
Console.WriteLine("B");
}
}

publicclassC:B
...{
publicC():base()
...{
Console.WriteLine("DEBUG:Cconstructing");
//base.GetYear();
this.GetYear();
}

protectedvoidGetYear()
...{
//base.GetYear();
Console.WriteLine("C");
}
}

}

通过这两个例子,终于好像彻底明白了虚函数和new(子类屏蔽父类的方法的关键字).

不过还有更cool点儿的.....请看下面的例子,仔细看小心头晕哦,哈:)

usingSystem;
usingSystem.Collections.Generic;
usingSystem.Text;

namespaceConsoleApplication2
...{
classProgram
...{
staticvoidMain(string[]args)
...{
//Aa=newA();
//Cc=newC();
Dd=newD();

//c.GetYear();
//b.GetYear();
}
}

publicclassA
...{
publicA()
...{
Console.WriteLine("DEBUG:Aconstructing");
this.GetYear();
}

protectedvirtualvoidGetYear()
...{
Console.WriteLine("A");
}
}

publicclassB:A
...{
publicB():base()
...{
Console.WriteLine("DEBUG:Bconstructing");
this.GetYear();
}

//protectedoverridevoidGetYear()
//{
////base.GetYear();
//Console.WriteLine("B");
//}
}

publicclassC:B
...{
publicC():base()
...{
Console.WriteLine("DEBUG:Cconstructing");
//base.GetYear();
this.GetYear();
}

protectedoverridevoidGetYear()
...{
//base.GetYear();
Console.WriteLine("C");
}

//protectednewvoidGetYear()
//{
////base.GetYear();
//Console.WriteLine("C");
//}

}

publicclassD:C
...{
publicD()
...{
Console.WriteLine("DEBUG:Dcontructing");
this.GetYear();
}

}

}

怎么样,发现了吧.虚函数和new的确有很多相似的地方,甚至如果仅以实现程序为目的的话,应该可以互换的,不是吗?

听起来怎么有点玄啊!没错,肯定不是的.是很相似,不过肯定有不一样的地方.可在哪里呢?