This print for content only-size & color not accurate 7" X 9-1/4" / casebound / malloy

// I'll draw anyone supporting IDraw3D.

static void DrawIn3D(IDraw3D itf3d)

{

Console.WriteLine("-> Drawing IDraw3D compatible type");

itf3d.Draw3D();

}

We could now test whether an item in the Shape array supports this new interface, and if so,

pass it into the DrawIn3D() method for processing:

C H A P T E R   9  

■

W O R K I N G   W I T H   I N T E R FA C E S

279

8849CH09.qxd  10/1/07  10:41 AM  Page 279

---

static void Main()

{

Console.WriteLine("***** Fun with Interfaces *****\n");

Shape[] s = { new Hexagon(), new Circle(),

new Triangle(), new Circle("JoJo") } ;

for(int i = 0; i < s.Length; i++)

{

...

// Can I draw you in 3D?

if(s[i] is IDraw3D)

DrawIn3D((IDraw3D)s[i]);

}

}

Notice that the Triangle type is never drawn in 3D, as it is not IDraw3D-compatible (see 

Figure 9-5).

Figure 9-5.

Interfaces as parameters