how to return a string from COM DLL

[Mann Khine]

I 've one function that 's written with COM DLL. I want to return a string from that function. function declaration is like that STDMETHODIMP CMyClass::Command() from that function how can I return a string. thanks in advance.

[Stephen Hewitt]

In the .IDL (or ODL file) change the declaration so it looks something like this:

HRESULT Command([out, retval] BSTR *pOut);

Now the function should look like this:

STDMETHODIMP CMyClass::Command(BSTR *pOut)
{
     if ( pOut == NULL )
     {
         return E_POINTER;
     }
 
     *pOut = SysAllocString(L"Your string here!");
     return S_OK;
}

If you're not familiar with BSTRs you should read up on them. Steve