2.7.txt

《Microsoft Visual C# .NET 2003开发技巧大全》源代码

Listing 2.7 Using Inheritance to Define a Related Set of Objects
using System;
namespace _8_Inheritance
{
// base class definition
public class MediaDevice
{
protected bool on = false;
virtual public void TurnOn()
{
on = true;
}
virtual public void TurnOff()
{
on = false;
}
}
public class Television : MediaDevice
{
private int curChannel = -1;
// turn on tv and set to channel 2
public override void TurnOn()
{
base.TurnOn ();
curChannel = 2;
}
// turns tv off
public override void TurnOff()
{
base.TurnOff ();
curChannel = -1;
}
public int Channel
{
get
{
return curChannel;
}
set
{
// can’t change channel if tv is off
if( on == false )
return;
curChannel = value;
}
}
}
class Class1
{
[STAThread]
static void Main(string[] args)
{
Television tv = new Television();
tv.TurnOn();
tv.TurnOff();
}
}
}