c++如何使用这个类和调用它

c+只会一点皮毛特来请教，如图，这个类使用不来，望写个调用例子

#include <iostream>
#include <string>

// ...

void func(int a, double b, const std::string& c) {
    std::cout << "a=" << a << ", b=" << b << ", c=" << c << '\n';
}

int main()
{
    int a = 1;
    double b = 2.0;
    std::string c = "hello";
    PluginSDK::CBackgroundTask task("test");
    task.SetRunTask(func, a, b, c);
    // ...
    return 0;
}

//CDocEventHandler.h
class CDocEventHandler
{
public:
    static void RegisterEventHandler(FS_LPVOID clientData);
protected:
    static void OnDocPermChange(FS_LPVOID clientData, FR_Document frDoc);
    static void OnDocCurrentWndProvideChange(FS_LPVOID clientData, FR_Document frDoc,FS_ByteString fbsWndProvideName);
    static void OnDocPageLabelChange(FS_LPVOID clientData, FR_Document frDoc);
protected:
    CDocEventHandler() { ; }
    ~CDocEventHandler() { ; }
    
    static FR_DocEventCallbacksRec m_frCallbacks;
};
 
 
 
//CDocEventHandler.cpp
FR_DocEventCallbacksRec CDocEventHandler::m_frCallbacks = { 0 };
void CDocEventHandler::RegisterEventHandler(FS_LPVOID clientData)
{
    m_frCallbacks.lStructSize = sizeof(FR_DocEventCallbacksRec);
    m_frCallbacks.clientData = clientData;
 
    m_frCallbacks.FRDocOnPermissionChange = OnDocPermChange;
    m_frCallbacks.FROnDocCurrentWndProvideChange = OnDocCurrentWndProvideChange;
    m_frCallbacks.FROnDocPageLabelChange = OnDocPageLabelChange;
 
    FRAppRegisterDocHandlerOfPDDoc(&m_frCallbacks);
}
 
//GlobalHandler.cpp实际的调用 
void CGlobalHandler::Initialize(HINSTANCE dllInstance)
{
    assert(dllInstance);
        //.....
    CDocEventHandler::RegisterEventHandler(nullptr);
    //.....
}

【调用示例代码】【仅供参考】

看下这个链接对博主有没有用
https://b23.tv/je9WZPs