I have a C++ DLL that accepts BSTR* and changes its value before
returning. I am calling this API from C#.
I get changed value in Object[] but not in actual variable. Please see
my code snippet to understand.

C++ DLL API:-
void Fun(BSTR* data) ;

C# wrapper:-
[DllImport("Test.dll", EntryPoint = "Fun", CharSet = CharSet.Auto,
CallingConvention = CallingConvention.StdCall)]
       public static extern void Fun(ref string data);

Calling from C#:-
string sHash = "";
Object[] objMethodParams ={ sHash };
MethodInfo.Invoke("", objMethodParams);

After the call, objMethodParams[0] shows the new changed string but
'sHash'  does not get updated with new value and still shows "".

I tried changing C# wrapper from 'void Fun(ref string data)' to 'void
Fun([in out] string data)' and this change made things worse, even
objMethodParams[0] started showing "".

Please let me know if you know solution.

Thanks
Ramesh