Creating a COM component in .NET 5 - .NET (Core and Framework) Discussion Boards

I was expecting at least 10 people to shout: Notepad++ !!!
For some reason, that didn't happen.

I presume that we are talking Windows. There is supposed to be a Linux version of it, but I never tried it under Linux, and don't know whether it is fully functional, stable or in other ways suitable.

Maybe even the Windows version doesn't satisfy your requirements. Maybe it doesn't satisfy your understanding of 'clear and understandable instructions'. Several years ago, I did add syntax coloring for another (script) language, and found it fairly simple - but I am not afraid of editing XML files by hand.

In any case, NPP is a great pure text editor. I have used it since I left DOS and Brief ... Some people say that NPP was more a clone of Brief than of Windows Notepad, and I tend to agree. Today it has developed far beyond either.

You can find NPP at notepad-plus-plus.org[^]

Thank you. I added highlighting keywords in Notepad++ for my language PPL (Parentheses Programming Language). It is working, not at all clear, but working. Good decision, I was looking enough time without result and was ready to write own utility for highligting, but instead of that I have time for other things. Thank you very much again and Happy New Year!

I'd like to port my WPF/.NET6 app to MAUI so I can target MacOS. I know MAUI is still a work in progress until next spring, but are there any good materials specifically on porting WPF to MAUI available yet?

FYI, in the research I've done so far, these are the biggest differences/issues I've found.

1. Control properties are not directly accessible and must be set with handlers with an IF branch for each targeted platform.

2. I'll have to learn the Xamarin flavor of XAML (I assume it's similar to WPF XAML).

3. I'll have to learn how to deploy MAUI apps. I've been using ClickOnce up to this point.

4. I'll need to buy a Mac and use Visual Studio for Mac to compile for the Mac OS target.

Is it "MAUI" or Xamarin you need to learn? You don't need a Mac to learn Xamarin and bet 6 months on vaporware.

It was only in wine that he laid down no limit for himself, but he did not allow himself to be confused by it.
― Confucian Analects: Rules of Confucius about his food

Thanks, Gerry. The available in-depth information on MAUI is spotty, but from what I understand one possible path is to start refactoring the WPF app into Xamarin now, and then there will be update tools (part of VS?) that should make porting from Xamarin to MAUI more straightforward.

My hope was that someone has already created a tutorial or video that took a specific look at what it would be like to go from WPF directly to MAUI. I'm sure there are some devil-in-the-details issues that's just not being discussed in the plethora of "Hello World" .NET6/MAUI presentations right now. I found one YouTube video here, but the audio is hard to follow. It's the right idea, but I was hoping for more of these.

As for needing a Mac, I think it can compile the project, but there's no emulator for testing in VS right now. This is all new to me. I have a decade of learning to catch up on.

Hi all. I am a newbie to writing API's. Should I start with ASP.NET Core or ASP.NET Framework? Can I use them for backend development too?

For new applications, start with the latest version - ASP.NET Core 6.0:
ASP.NET documentation | Microsoft Docs[^]
Get started with ASP.NET Core | Microsoft Docs[^]

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Hi,

I'm trying to create a simple COM component in .NET 5. I have gotten this far:

I have created an interface with the right attributes:

C#

[ComVisible(true)]
[Guid("12345678-3e60-4c56-abcd-13d4098434f7")]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
public interface IConvertor
{
    string ConvertPatient(string s);
}

I have created a class that implements this interface:

C#

[ComVisible(true)]
//[ClassInterface(ClassInterfaceType.None)]
public class Convertor : IConvertor
{
    public Convertor()
    { }

    public string ConvertPatient(string s)
    {
        return "Hello, " + s;
    }
}

I tried with and without the ClassInterface and Guid attributes.

In the .csproj file I added these:

XML

<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
    <TargetFramework>net5.0</TargetFramework>
    <!-- Indicate the assembly is providing a COM server -->
    <EnableComHosting>true</EnableComHosting>
    <EnableRegFreeCom>true</EnableRegFreeCom>
</PropertyGroup>
<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
  <PlatformTarget>x86</PlatformTarget>
</PropertyGroup>
<ItemGroup>
    <PackageReference Include="Hl7.Fhir.R4" Version="3.6.0" />
</ItemGroup>
</Project>

I compiled for x86 and I got these files (and some more):
xxx.comhost.dll
xxx.dll

The problem is that I don't manage to register this component.
tlbexp xxx.InterOp.dll gives me this error:

Quote:
TlbExp : error TX0000 : Type library exporter encountered an error while processing 'hdmpcloud.ehealth.FhirTools.InterOp.Convertor, hdmpcloud.ehealth.FhirTools.InterOp'. Error: Type library exporter cannot load type 'hdmpcloud.ehealth.FhirTools.InterOp.Convertor' (error: Could not load file or assembly 'System.Runtime, Version=5.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. The system cannot find the file specified. (Exception from HRESULT: 0x80070002)).

regasm /tlb xxx.InterOp.comhost.dll gives me

Quote:
RegAsm : error RA0000 : Failed to load 'C:_projects\HDMP\hdmpcloud.ehealth.FhirTools\InterOp\hdmpcloud.ehealth.FhirTools.InterOp\bin\Debug\net5.0\hdmpcloud.ehealth.FhirTools.InterOp.comhost.dll' because it is not a valid .NET assembly

I want to call this component from a Delphi program (unmanaged code).

The documentation ( Interoperating with unmanaged code - .NET Framework | Microsoft Docs ) is not very clear on a couple of things:

Is COM still possible in .NET 5?
The documentation is for .NET in general, but they don't specify a version.

Any help or pointers in the right direction would be much appreciated. And before you ask... yes, this will become an article Smile | :)

Gaston

Check out my blog at http://msdev.pro/

The file you're trying to register seems to have no relation to "Convertor"; at least as far as naming goes. And I would have picked a more unique name than "Convertor".

It was only in wine that he laid down no limit for himself, but he did not allow himself to be confused by it.
― Confucian Analects: Rules of Confucius about his food

Hi Gerry,

Thanks for the tips. But I'm afraid that changing the names will not help in registering the COM component. If you have tips for that I'll be glad to hear them.

Thanks,
Gaston

Check out my blog at http://msdev.pro/

Maybe this will help:

Quote:
I used regasm.exe /tlb /codebase to register it

[Solved] .net Call C# dll from Delphi - Code Redirect

dll - RegAsm - When is the /codebase option applicable? - Stack Overflow

It was only in wine that he laid down no limit for himself, but he did not allow himself to be confused by it.
― Confucian Analects: Rules of Confucius about his food

Thanks for the link!

Unfortunately it doesn't help. It seems that regasm doesn't recognize .NET 5 assemblies. Regsvr32 does, and it registers the component / interface / library, but no TLB is generated. That makes it virtually useless.
From Exposing .NET Core components to COM | Microsoft Docs :

Quote:
Unlike in .NET Framework, there is no support in .NET Core or .NET 5+ for generating a COM Type Library (TLB) from a .NET assembly. The guidance is to either manually write an IDL file or a C/C++ header for the native declarations of the COM interfaces.

So now I'm investigating how to create / compile / use the correct IDL file. Should anyone have some good pointers for that, let me know Smile | :)

Thanks,
Gaston

Check out my blog at http://msdev.pro/

I'm for the path of least resistance. Unless you need "real time", I would've windows message queues; at least to start with; which might be real enough.

Easily Implement Message Queue Communications Protocols In Your Windows Applications

It was only in wine that he laid down no limit for himself, but he did not allow himself to be confused by it.
― Confucian Analects: Rules of Confucius about his food

Hi Gerry,

I was under the assumption that creating a COM component would still be as easy under .NET 5 as under the previous versions. We don't need real time at all.
This would be part of a conversion program, that will run on the client PCs (> 3000 clients, with all sorts of PCs and OS's). I wanted to avoid having to serialize objects on the Delphi side, and to deserialize them on the .NET side. I think that we will resort to creating a file (or a couple of files) in a folder, and when that is done running the conversion program on the client PC. That way we only have to install .NET 5 and the conversion program, which is even easier than using a queue.

Thank you for thinking with me for solutions!

I am going to do 1 more try, posting the same question on SO. Please don't be insulted Wink | ;-)

If I find a solution I will post it here.

Check out my blog at http://msdev.pro/

Seems it's more of a "command and control" issue than a data transfer one. Lots of possible scenarios.

It was only in wine that he laid down no limit for himself, but he did not allow himself to be confused by it.
― Confucian Analects: Rules of Confucius about his food

Indeed, we have thought of alternatives before going to the "COM road". But COM seemed the easiest in our case for a couple of reasons, hence the initial question here.

Check out my blog at http://msdev.pro/

According to the replies on SO this is a dead end indeed.
We now are going to create classes in C# and in Delphi with all the same properties. We'll then serialize the Delphi classes to JSON, and deserialize them in C#.
For this I'm writing a code generator that will use a DSL to describe the classes. It's a work-around, but at least we'll get the work done.

Check out my blog at http://msdev.pro/

That's the protocol; you still need a transport mechanism.

It was only in wine that he laid down no limit for himself, but he did not allow himself to be confused by it.
― Confucian Analects: Rules of Confucius about his food

This is for a conversion, so the Delphi side will serialize the objects in a folder, and the .NET part will deserialize it and handle it further.
It is a One Shot operation, so no need for fancy stuff there.

Check out my blog at http://msdev.pro/

Hi All, I hope now this is the correct forum for suggestions. This Type bottoms need to be bigger and more precise so people did not get flagged for asking a suggestion that i found unnecessary for been flagged, If someone here knows any type of free code camp please share the resource I immensely trying to enhanced my knowledge and I know someone of you there knows some free learning resources.

Thank you

You forgot to explain what it is you want to learn about.

Based on the subject, I'm tempted to post a link to this Wikipedia article[^]. Big Grin | :-D

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

go head you discover america

a lot ppl here think are poets.. pls gime a break.

Not a Rick Roll[^]

Bastard Programmer from Hell Suspicious | :suss:

"If you just follow the bacon Eddy, wherever it leads you, then you won't have to think about politics." -- Some Bell.