About code. Mostly on C++
Problem I have recently migrated a C# 2.0 project registered for COM interop to .NET 4.5 and when I imported the type library in a C++ project with no_registry, suddenly I got some errors because the type library could not be imported. Here are the steps to reproduce: create a .NET Class Library project and…
Not long ago I ran into a COM interop problem that was a bit tricky to fix. So I’m sharing the problem and the solution here in case others encounter the same problem. I had this native in-proc COM server that initially was built only for x86. It was used in a native MFC application…
Windows Runtime, or shortly WinRT, is a new runtime (siting on top of the Windows kernel) that allows developers to write Metro style applications for Windows 8, using a variety of languages including C/C++, C#, VB.NET or JavaScript/HTML5. Microsoft has started rolling out information about Windows 8 and the new runtime at BUILD. WinRT is…
I’ve ran recently across this question: how to find (using C++) if a computer is a laptop? That is possible with WMI and many answers (such as this) point to the Win32_SystemEnclosure class. This class has a member called ChassisTypes, which is an array of integers indicating possible chassis types. At least one of them…
It is possible to register both 32-bit and 64-bit versions of the same COM server on 64-bit machine. This leads to several questions such as how are they registered and which one of the two is used. I will try to answer them below. But first, let’s start with an example. Example Let’s say we…
If you work with COM, apartments is one of the concepts you must comprehend, because it’s an important topic. Before explaining what apartments are let’s think about classes and objects regardless of COM. When you build a class, you know (or you should) whether objects of that class will be used from a single thread,…
If you are working with COM there are several registry entries that are important and that you need to understand. I will try in this post to clarify them. But before that, let’s enumerate the three possible COM server scenarios. (As a side note, a COM server is a DLL or EXE can contains one…
.NET allows you to expose components as COM and consume them from unmanaged code. There are many references on how to this (and you can only start with MSDN), and I will not talk about that part. What I want to explain here is something different. Suppose you have this interface: [Guid(“2F8433FE-4771-4037-B6B2-ED5F6585ED04”)] [InterfaceType(ComInterfaceType.InterfaceIsIDispatch)] public interface…