Creating COM in VB.NET for VB6

[CFB]

I'm just learning (and getting used to) the .NET framework. I've done some searching around (including these forums) and from what I understand, the use/creation of COM objects has been done away with/changed the introduction of .NET. I can't seem to nail down the specific answer to my question though.

Is it possible to create a VB.NET COM component that could be used by a VB6 application? We've got several VB6 apps that need to use Web Services and I thought it'd be easier to create a VB.NET COM component to access these services via VB6 than it would be to implement the SOAP toolkit. Any help is appreciated. Thanks.

 

[JohnYingling]

Yes you can create a component that is callable by COM. You create a .Net component that can be called by COM through a a Com Callable Wrapper. However, the Net Framework must be installed on all machines that will use the .Net Component.

"NET Framework Developer's Guide

COM Callable WrapperSee Also
COM Wrappers | COM Callable Wrapper | Simulating COM Interfaces | Runtime Callable Wrapper | Exposing .NET Framework Components to COM
When a COM client calls a .NET object, the common language runtime creates the managed object and a COM callable wrapper (CCW) for the object. Unable to reference a .NET object directly, COM clients use the CCW as a proxy for the managed object.

The runtime creates exactly one CCW for a managed object, regardless of the number of COM clients requesting its services. As the following illustration shows, multiple COM clients can hold a reference to the CCW that exposes the INew interface. The CCW, in turn, holds a single reference to the managed object."

http://www.VBResizer.com

Forms/Controls Resizing/Tabbing Control

http://www.VBCompare.com

Compare Code (Text)

http://www.VBSortGen.com

Generate Sort Class in VB or VBScript

 

[chiph]

I haven't done this in VB.NET, but in C# creating a CCW is an option in the project properties -- look for "register for COM Interop" or something similar.

Chip H.


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