C# 不支持多重继承。要实现多重继承，请使用接口。
这是类 Shape 中的接口 PaintCost -
public interface PaintCost {
int getCost(int area);
}形状是我们的基类，而矩形是派生类 -
class Rectangle : Shape, PaintCost {
public int getArea() {
return (width * height);
}
public int getCost(int area) {
return area * 80;
}
}现在让我们看看在 C# 中实现多重继承接口的完整代码 -
Using System;
namespace MyInheritance {
class Shape {
public void setWidth(int w) {
width = w;
}
public void setHeight(int h) {
height = h;
}
protected int width;
protected int height;
}
public interface PaintCost {
int getCost(int area);
}
class Rectangle : Shape, PaintCost {
public int getArea() {
return (width * height);
}
public int getCost(int area) {
return area * 80;
}
}
class RectangleDemo {
static void Main(string[] args) {
Rectangle Rect = new Rectangle();
int area;
Rect.setWidth(8);
Rect.setHeight(10);
area = Rect.getArea();
// Print the area of the object.
Console.WriteLine("Total area: {0}", Rect.getArea());
Console.WriteLine("Total paint cost: ${0}" , Rect.getCost(area));
Console.ReadKey();
}
}
} 
