DirectShow AMCap改装， 无法解析的外部符号 "class CFactoryTemplate * g_Templates"

[qq_35084700]

错误 1 error LNK2001: 无法解析的外部符号 "class CFactoryTemplate * g_Templates" (?g_Templates@@3PAVCFactoryTemplate@@A)
错误 2 error LNK2001: 无法解析的外部符号 "int g_cTemplates" (?g_cTemplates@@3HA)


1>strmbase.lib(dllentry.obj) : error LNK2001: 无法解析的外部符号 "class CFactoryTemplate * g_Templates" (?g_Templates@@3PAVCFactoryTemplate@@A)
1>strmbase.lib(dllentry.obj) : error LNK2001: 无法解析的外部符号 "int g_cTemplates" (?g_cTemplates@@3HA)

把AMCap代码文件复制到MFC工程里面，出现上述两个错误：STRMBASE.lib已经链接，不知道问题出在哪。
dllentry.cpp里面与上面相关的代码是：

extern CFactoryTemplate g_Templates[1];
extern int g_cTemplates;

//called by COM to get the class factory object for a given class
STDAPI
DllGetClassObject(
REFCLSID rClsID,
REFIID riid,
void **pv)
{
if (!(riid == IID_IUnknown) && !(riid == IID_IClassFactory)) {
return E_NOINTERFACE;
}

// traverse the array of templates looking for one with this
// class id
for (int i = 0; i < g_cTemplates; i++) {
const CFactoryTemplate * pT = &g_Templates[i];
if (pT->IsClassID(rClsID)) {

// found a template - make a class factory based on this
// template

*pv = (LPVOID) (LPUNKNOWN) new CClassFactory(pT);
if (*pv == NULL) {
return E_OUTOFMEMORY;
}
((LPUNKNOWN)*pv)->AddRef();
return NOERROR;
}
}
return CLASS_E_CLASSNOTAVAILABLE;
}

//
// Call any initialization routines
//
void
DllInitClasses(BOOL bLoading)
{
int i;

// traverse the array of templates calling the init routine
// if they have one
for (i = 0; i < g_cTemplates; i++) {
const CFactoryTemplate * pT = &g_Templates[i];
if (pT->m_lpfnInit != NULL) {
(*pT->m_lpfnInit)(bLoading, pT->m_ClsID);
}
}

}

[qq_35084700]

#ifdef FILTER_DLL /* List of class IDs and creator functions for the class factory. This provides the link between the OLE entry point in the DLL and an object being created. The class factory will call the static CreateInstance function when it is asked to create a CLSID_SystemClock object */ CFactoryTemplate g_Templates[1] = { //{&CLSID_SystemClock, CSystemClock::CreateInstance} { L"SystemClock", &CLSID_SystemClock, CSystemClock::CreateInstance} }; int g_cTemplates = sizeof(g_Templates) / sizeof(g_Templates[0]); #endif 找到问题了，楼上两位都说得对，表面上看是STRMBASE.lib的问题，而STRMBASE.lib是编译自BaseClasses。上面的代码是关键，截取自BaseClasses项目的sysclock.cpp，FILTER_DLL没有预定义，所以出现问题，添加预定义就好了。

[zgl7903]

extern CFactoryTemplate g_Templates[1]; 实例在哪里？ 需要 CFactoryTemplate g_Templates[1];

[oyljerry]

g_Templates这个要有地方在别的cpp中定义全局变量