C# 重载 overload,重写override覆盖

重载overload

派生类和基类的方法同名，其中访问修饰符(public,private,protected,internal,protected internal)，返回类型，参数类型，个数，顺序中的一个或若干可以不同，实现可以不同；

重写override

必须对抽象类中声明的abstract方法override实现抽象类的抽象方法。可以重写virtual虚函数

interface IMath
{
void Add(int x, int y);
}

public abstract class FirstAbstractClass : IMath
{
public void Add(int x, int y)
{
Console.WriteLine("This is the abstract class add method:{0}+{1}={2}", x, y, x + y);
}

public abstract void Add(int x, int y,int z);

public virtual void Add(int x,int y,int m,int n)
{
Console.WriteLine("This is the virtual method in abstract class :{0}+{1}+{2}+{3}={4}", x, y, m, n, x + y + m + n);
}
}

public class ConcreteClass : FirstAbstractClass
{
public override void Add(int x, int y, int z)
{
Console.WriteLine("This is the implementation of the abstract method from abstract class! {0}+{1}+{2}={3} ", x, y, z, x + y + z);
}

public override void Add(int x, int y, int m, int n)
{
Console.WriteLine("This is the implementation of the virtual method from the abstract class,it's not compulsory! {0}+{1}+{2}+{3}={4}", x, y, m, n, x + y + m + n);
}
}
class Program
{
static void Main(string[] args)
{
int x = 9876, y = 9876, z = 876, w = 65687;
ConcreteClass obj = new ConcreteClass();
obj.Add(x, y);
obj.Add(x, y, z);
obj.Add(x, y, z, w);
Console.ReadLine();
}
}