C ++ dynamically loads classes in DLL (used to create Objects Based on the string class name)

References:

Http://blog.csdn.net/yysdsyl/archive/2008/07/08/2626033.aspx

Used to generate DLL files:

////////////////////////////Test.hclass Test{public:    Test(void);public:    virtual ~Test(void);public:    virtual void DoSth()=0;};

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/// // Ttest. h /////////// ttest inherited from testclass ttest: public test {public: ttest (void); Public :~ Ttest (void); Public: Virtual void dosomething () {STD: cout <"ttest: Do something/N ";};};

//// // Key extern "C" _ declspec (dllexport) test * createttestptr (); extern "C" _ declspec (dllexport) void deletettestptr (test * t );

 

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////////////////TTest.cpp#include "TTest.h"TTest::TTest(void){}TTest::~TTest(void){    std::cout<<"destruct TTest/n";}Test* CreateTTestPtr(){    return new TTest();}void DeleteTTestPtr(Test* t){    if(t!=NULL)        delete t;}

Test procedure:

#include "Test.h"#include <Windows.h>typedef Test* (CREATEFN)();typedef void (DELETEFN)(Test* );int _tmain(int argc, _TCHAR* argv[]){    HINSTANCE hd=::LoadLibrary("AnotherDll.dll");    CREATEFN* pfn;    DELETEFN* xfn;    pfn=(CREATEFN *)::GetProcAddress(hd,"CreateTTestPtr");    xfn=(DELETEFN *)::GetProcAddress(hd,"DeleteTTestPtr");        Test* t=(*pfn)();    t->DoSth();    (*xfn)(t);    getchar();    return 0;}
 
 
 
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When adding a new class to the DLL that inherits from the test base class, you can implement the following two functions at the same time.
extern "C" __declspec(dllexport) Test* CreateXXXPtr();extern "C" __declspec(dllexport) void DeleteXXXPtr(Test* t);
 
(Xxx indicates the name of the newly added class. Of course, the name can be customized. As long as you can find the two export functions in the application, the naming rules are uniform.
It is good to create an object based on the class name)