ATL Problems??

[Leesen]

Hi, all Some problems about ATL Com: 1.I have create two ATL Object: CStudent and CTeacher . The simple source code listed as follow: (some code auto generated by ATL have been skiped) class CStudent { private: long m_age; public: CStudent():m_age(10) { } //...other code auto generated by ATL }; class CTeacher { private: IStudent* m_aStudent; public: CTeacher() { //create an instance of the com CoCreateInstance(CLSID_Student,NULL,CLSCTX_ALL,IID_IStudent, (void**)&m_aStudent); } //...other code auto generated by ATL } 2.Then I add a "IStudent * OneStudent" property for ITeacher ,to access the m_aStudent. The implemention of the property are listed as below: STDMETHODIMP CTeacher::get_OneStudent(IStudent *pVal) { AFX_MANAGE_STATE(AfxGetStaticModuleState()) // TODO: Add your implementation code here *pVal = * m_aStudent; return S_OK; } STDMETHODIMP CTeacher::put_OneStudent(IStudent *newVal) { AFX_MANAGE_STATE(AfxGetStaticModuleState()) // TODO: Add your implementation code here *m_aStudent = *newVal ; return S_OK; } 3.Now I type some VB code to test the com ,but some compiler errors occurrs. VB Code: Dim s As Student Dim t As New Teacher s = t.OneStudent the last sentence "s = t.OneStudent" have compiler errors. Errors:function or interface marked as restricted ,or the function use an Automation type not supported in Visual Basic I guess the errors caused by the type dismatch between IStudnet and CStudent.But I did not know how to resolve it . So who can tell me how to return the m_aStudent that can be supproted in vb?? thx. Regards.

[Vi2]

// Must have more than 1 inderection of pointer // In idl-file [...] HRESULT OneStudent([out,retval]IStudent* *pVal); STDMETHODIMP CTeacher::get_OneStudent(IStudent* *pVal) { AFX_MANAGE_STATE(AfxGetStaticModuleState()) // TODO: Add your implementation code here *pVal = m_aStudent; if( m_aStudent != NULL ) m_aStudent->AddRef(); return S_OK; } // In idl-file [...] HRESULT OneStudent([in]IStudent* newVal); STDMETHODIMP CTeacher::put_OneStudent(IStudent *newVal) { AFX_MANAGE_STATE(AfxGetStaticModuleState()) // TODO: Add your implementation code here if( m_aStudent != NULL ) m_aStudent->Release(); m_aStudent = newVal ; if( m_aStudent != NULL ) m_aStudent->AddRef(); return S_OK; } In VB you should use the "Set" operator to assign one object to another. Set s = t.OneStudent With best wishes, Vita