I need to use a COM object in my .NET 2.0 compact framework project, but I can't use the CreateObject function. Is there any other way to call a COM object that will work in my environment?
You'll need to call CoCreateInstance(). You can find a P/Invoke declaration for it here. If you only have a ProgID then you need to call CLSIDFromProgID() first. Make sure you've exhausted all possibilities of finding a type library for the COM server (Tlbimp.exe), this kind of code isn't easy to get right.
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Has anybody tried to use C++/winrt to create Win32 COM objects? The C++/winrt docs document that consuming them is possible and of course creating "new" UWP COM objects. I was wondering if for some simple scenario's one could use the C++/winrt headers instead of ATL to generate some simple COM objects.
You can write a COM component with C++/WinRT. Here’s an example of a COM executable server but the principles and techniques are much the same for a DLL.
https://gist.github.com/kennykerr/d983767262118ae0366ef1ec282e428a
For a DLL you just want to make sure you export an implementation of DllGetClassObject and DllCanUnloadNow. Otherwise, its just like any other DLL and you can use the winrt::implements class template to implement the various classes and factories.
I have followed the example here: http://msdn.microsoft.com/en-us/library/vstudio/jj822931.aspx to create an In-proc Classic COM DLL using Windows Runtime Template Library (WRL). I am also able to modify to code to run the DLL as COM surrogate (wrapped inside DllHost.exe).
However, I couldn't find the way to create an out-of-process COM EXE using the WRL. There is a simple example using barebone COM API here: http://www.codeproject.com/Articles/3173/A-simple-yet-debuggable-COM-skeleton-code, but I'd like to know how I can utilize WRL to simplify that.
Thanks.
Yes it is possible. I just got one working. Here's the basics that are required, as compared to implementing an in-proc coclass.
Implement your coclass using WRL::RuntimeClass the same way you would for an in-proc class. (https://msdn.microsoft.com/en-us/library/jj822931.aspx)
In your main function, create a module object using WRL::Module<OutOfProc>::Create(), and call module.RegisterObjects() on startup, and module.UnregisterObjects() and module.Terminate() on shutdown.
You need to build a DLL to host the proxies: https://msdn.microsoft.com/en-us/library/windows/desktop/ms688707(v=vs.85).aspx
Static Registrations: DO register the Interface and the CLSID of your proxy stub. DO NOT statically register your coclass.
In the Client, when you call CoCreateInstance, be sure to use the appropriate CLSCTX. (I use CLSCTX_ALL when the hosting model is not important to the client.)
(I know it's been almost 4 years, but I had the same question this week.)
I know it's a bit old school, but I have to translate an LDAP function written in VB (Visual Basic not .net). And using managed code I can't produce the same result.
To solve the problem quickly I would like to use COM (Component Object Model) exactly as the Visual Basic function is doing like this:
set dso=GetObject("LDAP:")
I'm completely out of practice with COM, what DLL would I need to include as a reference to make it work?
I believe Marshal.GetActiveObject is the equivalent to the VB GetObject call you are used to using.
This will return you the object, you then need to either:
Reference an interop assembly with the type definitions for your LDAP object
Make the calls to the object using reflection invoke
Use the dynamic keyword in C# 4.0 to make the calls to the object using a late bound mechanism, similar to what VB did
I recommend using option 3 if you are using .Net 4.0
Is there any way I can reference and use classes and methods from a managed .net assembly from within a totally unmanaged C++ application? (no /clr)
Absolutely, and this gem from CodeProject should prove helpful
You need a CCW (COM callable wrapper).
You can - by hosting the CLR. I found one set of example code here . I have no way of knowing how good the advice there is though, as I've never done it.
You can expose the .NET class thru COM and consume the classes thru COM.
how to use a method inside a com dll into C# ?
Best way to access COM objects from C#
Add a reference to the com dll and .net will automatically give a wrapper class and by using that you can call functions inside the dll.