new、override关键字

1.如果我想彻底覆盖父类的方法，此时可以使用override

.假有classB继承自classA，代码如下：

    public class B : A
    {
        public bool _flag;
        public B(bool flag)
        {
            _flag = flag;
        }
        protected override void Write()
        {
            Console.Write("Class B");
        }
        public override void SayHello()
        {
            if (_flag)
            {
                base.SayHello();
            }
            else
            {
                this.Write();
            }
        }
    }
    public class A
    {
        protected virtual void Write()
        {
            Console.Write("Class A");
        }
        public virtual void SayHello()
        {
            this.Write();
        }
    }

View Code