Public Property Let MyProperty(sValue As String)
Try it and you get the following error:
Implementing property must have matching 'ReadOnly' or 'WriteOnly' specifiers.
This is a known bug and the only solution is to modify your COM interface (in your original VB6 dll) so that the arguments are passed by-value:
Public Property Let MyProperty(ByVal sValue As String)
Which, under the covers, changes the COM interface from:
HRESULT MyProperty([in, out] BSTR* );
HRESULT MyProperty([in] BSTR );
But of course, I don't want to change the COM interface - I want to implement the interface that has already been defined and is already being used by multiple legacy applications.
Or I can use C#, which handles these Public Properties just fine.
So I'm caught in a bind - only C# can handle the Public Properties, and only VB.Net can handle the Optional String Parameters. I'm going to have to break my COM interface and force multiple client recompilations... OR use a VB6 COM facade that calls my .Net dll.
A tough choice - yuck, yucky, or yuckier?