CustomQueryInterface Sample

In the CLR v4 there is a new interface called ICustomQueryInterface. This very cool new feature will enable developers to provide their own managed implementation of custom and standard COM interfaces (except IUnknown).

CustomQueryInterface Sample

One interesting scenario, which will be illustrated in the sample below, is dynamic managed aggregation with a flexible implementation of IDispatch.

In this sample, we will show an implementation of ICustomQueryInterface through a managed IDispatch implementation that overrides the default IDispatch implementation by the CLR a managed COM aggregation system where both Outer and Inner objects are managed objects.

CustomIMarshal Sample

To further demo the power of CustomQueryInterface and the ability to use the .NET technology (WCF) within COM world, this sample targets the customization of IMarshal interface by using WCF.

IMarshal enables a COM object to define and manage the marshaling of its interface pointers. On the other hand, WCF provides serialization facilities that enable loose coupling, which significantly eases the customization of IMarshal and makes it more flexible.

In this sample, we provide three important things:

• A managed class acts as the COM component which also implements a WCF service.
• A managed class acts as the COM proxy which contains the WCF client.
• A program that demos the usage of the two classes above by passing the IUnknown pointer through the global stream.

License

The CustomQueryInterface and CustomIMarshal samples are licensed under Microsoft Limited Public License (Ms-LPL).

Ms-LPL is based on Microsoft Public License (Ms-PL), but there is a Windows-platform limitation:

4. (F) Platform Limitation- The licenses granted in sections 2(A) & 2(B) extend only to the software or derivative works that you create that run on a Microsoft Windows operating system product.