Using the ATL Interface Wizard from Visual C++ 5.0 to add a method to an
interface, you will get compilation errors C2061 if you specified any of
the following for parameters in the dialog box:
SAFEARRAY(type) pSA
SAFEARRAY(type) *ppSA
This problem is caused by a limitation in the ATL COM Interface Wizard.
To cause the ATL code to compile, you must make modifications to the method
that was added with the ATL COM Interface wizard in the .h and .cpp files.
The correct declarations and definitions that must be used for each of the
known data types that cause the problems are shown below (assume that the
interface is IATLObj and the ATL class that is implementing the interface
is CATLObj):
For instance, the following are wizard-generated function prototypes in the
.h file:
STDMETHOD(Test)(SAFEARRAY(BSTR) *ppArrayBstr);
STDMETHOD(Test2)(SAFEARRAY(BSTR) pArrayBstr);
The correct declarations for header file should be:
STDMETHOD(Test)(SAFEARRAY **ppArrayBstr);
STDMETHOD(Test2)(SAFEARRAY *pArrayBstr);
The correct definitions for source file should be:
STDMETHODIMP CATLObj::Test(SAFEARRAY **ppArrayBstr)
{
return S_OK;
}
STDMETHODIMP CATLObj::Test2(SAFEARRAY *pArrayBstr)
{
return S_OK;
}
You will notice that if you use the above method, the Class view
information in the Tree view may look different for CATLObj. Test and Test2
will not be in the IATLObj interface section in Class view for CATLObj as
they were before. They are now in the member function section. You can
correct this behavior by not making the changes above; and instead, using a
macro. To do this, make the following modifications to the header file
before the class definition:
#define SAFEARRAY(X) SAFEARRAY*
Class view will now properly display the new methods under the interface
section instead of under the member function section.
Microsoft has confirmed this to be a bug in the Microsoft products
listed at the beginning of this article.
Steps to Reproduce Behavior
- Create a new ATL/COM Application Wizard Project.
- Insert a new ATL COM Object with the default settings.
- Add a new method with the ATL COM Object Wizard by right-clicking the
interface to add the method and selecting "Add Method."
- Give the method a name.
- Add one parameter with SAFEARRAY(BSTR)* as the type. For example:
[out] SAFEARRAY(BSTR) *pArrayBSTR
- Build the project.
You will receive Compiler Error C2061 due to the incorrect syntax for the
parameter in the header and source files.
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