各位专家: 看看下面一段程序 实现什么功能 尤其是#ifdef RUN_ON_WEBNAVIGATOR 是什么意思 ?


#define TAG1 "@local::04_button"

#define PicNameButton1 "04-Trends-Buttons-Set1"
#define PicNameButton2 "04-Trends-Buttons-Set2"
#define WebPic "Webscreen"

double picture;

#ifdef RUN_ON_WEBNAVIGATOR

picture = GetPropDouble(WebPic ,"04_Buttons","FontSize");

#else

picture = GetTagDouble(TAG1 ); //Button Set

#endif


switch ((int)picture){
case 1:
return PicNameButton1;
break;
case 2:
return PicNameButton1;
break;
case 3:
return PicNameButton1;
break;
case 4:
return PicNameButton1;
break;
case 5:
return PicNameButton1;
break;
case 6:
return PicNameButton1;
break;
case 7:
return PicNameButton1;
break;
case 8:
return PicNameButton1;
break;
case 9:
return PicNameButton1;
break;
case 11:
return PicNameButton2;
break;
case 12:
return PicNameButton2;
break;
case 13:
return PicNameButton2;
break;
case 14:
return PicNameButton2;
break;
case 15:
return PicNameButton2;
break;
case 16:
return PicNameButton2;
break;
case 17:
return PicNameButton2;
break;
case 18:
return PicNameButton1;
break;
case 19:
return PicNameButton2;
break;
case 20:
return PicNameButton2;
break;
case 21:
return PicNameButton2;
break;
default:
{
return PicNameButton1;
}
}






}