Nebula2探秘05-RTTI

于 2006-09-24 13:34:00 发布 · 91 阅读

本文通过示例代码介绍了Nebula2中RTTI（运行时类型识别）的实现方式，主要依赖于nClass和nObject，演示了如何使用IsA()和IsInstanceOf()方法来判断类的继承关系及对象的实例关系。

Nebula2探秘05-RTTI

happykevins文

Nebula2的RTTI支持都是在nObject这一层实现的，每个继承自nObject的类都有IsA()和IsInstanceof()两个方法，前者用于判断继承关系，后者则用于判断一个对象是否为指定类的实例，下面的代码说明了他们的用法。

/****************************************************************************/
/*Nebula2-Tutorial05*/
/*Nebula2RTTI*/
/*author:happykevins*/
/****************************************************************************/

///----------------------------------------------------------------------------
///+必要头文件
#include"kernel/nkernelserver.h"
#include"kernel/ntimeserver.h"
#include"kernel/nfileserver2.h"
///-必要头文件
///----------------------------------------------------------------------------

///----------------------------------------------------------------------------
///+链接库
#pragmacomment(lib,"wsock32.lib")
#pragmacomment(lib,"d_nkernel.lib")
///-链接库
///----------------------------------------------------------------------------

///----------------------------------------------------------------------------
///+Application
intmain(intargc,constchar**argv)
{
///创建KernelServer
nKernelServer*ks=n_new(nKernelServer);

///----------------------------------------------------------------------------
///+Nebula2RTTITest
///@note:
///Nebula2RTTIimplementmostlydependsonnClass&&nObject

///firstly:wegotsomeinstance(allinheritedfromnObject)
nRoot*nroot=(nRoot*)ks->New("nroot");
nObject*nobject=(nObject*)ks->New("nobject");
nTimeServer*ntimeserver=(nTimeServer*)ks->Lookup("/sys/servers/time");
nFileServer2*nfileserver2=(nFileServer2*)ks->Lookup("/sys/servers/file2");

///secondly:TestRTTIInfo.
///use'IsA'&'IsInstanceOf'methods

//1.nrootisanroot?
n_printf("[%s]is%s[%s] ",
nroot->GetClass()->GetName(),
nroot->IsA("nroot")?"\b":"not",
"nroot");
//2.nrootisanobject?
n_printf("[%s]is%s[%s] ",
nroot->GetClass()->GetName(),
nroot->IsA(ks->FindClass("nobject"))?"\b":"not",
"nobject");
//3.nobjectisanroot?
n_printf("[%s]is%s[%s] ",
nobject->GetClass()->GetName(),
nobject->IsA("nroot")?"\b":"not",
"nroot");
//4.ntimerserverisanroot?
n_printf("[%s]is%s[%s] ",
ntimeserver->GetClass()->GetName(),
ntimeserver->IsA("nroot")?"\b":"not",
"nroot");
//5.nrootisinstanceofnroot?
n_printf("[%s]is%sinstanceof[%s] ",
nroot->GetClass()->GetName(),
nroot->IsInstanceOf(ks->FindClass("nroot"))?"\b":"not",
"nroot");
//6.nrootisinstanceofnobject?
n_printf("[%s]is%sinstanceof[%s] ",
nroot->GetClass()->GetName(),
nroot->IsInstanceOf(ks->FindClass("nobject"))?"\b":"not",
"nobject");
//7.nfileserver2isanobject?
n_printf("[%s]is%s[%s] ",
nfileserver2->GetClass()->GetName(),
nfileserver2->IsA("nobject")?"\b":"not",
"nobject");
//8.nfileserver2isantimeserver?
n_printf("[%s]is%s[%s] ",
nfileserver2->GetClass()->GetName(),
nfileserver2->IsA("ntimeserver")?"\b":"not",
"ntimeserver");

///+Nebula2RTTITest
///----------------------------------------------------------------------------

///销毁KernelServer
n_delete(ks);

getchar();
return0;
}
///-Application
///----------------------------------------------------------------------------