An out-of-proc COM-server runner for C#.
##What kind of COM objects are there? Microsoft COM comes in multiple flavors, each with its own pro's and con's.
- The in-proc server makes it easy to create an object from an external DLL and use it in your native code.
- The out-of-proc server lets you start a separate process, or attach to an existing process, where you can offload part of your work. The process can even be running on a separate server, without you having to care about how it is implemented!
##Why use Trustfall.ComServer? Unfortunately .Net Framework only supports creating in-proc COM-servers by default. Microsoft has tried to remedy this with technical papers and samples describing how to create out-of-proc servers in .Net languages, for example with their COM Interop Tutorials at https://msdn.microsoft.com/en-us/library/aa645712(v=vs.71).aspx. Unfortunately those tutorials are quite complex, have many moving parts and are hard to follow or troubleshoot. This project wraps the COM server-side code into a helper class library which you can use to build your own out-of-proc COM servers.
##Demo application Start the solution in Visual Studio and build it. The server component is automatically registered as a LocalServer32 COM-object as a post-build event.
With Task Manager running, start two instances of Demo.Client and send a couple of echo requests. Each client creates its own server instance, running in the same server-side process. You see in the Task Manager that there is exactly one process called Demo.Server. Demo.Server keeps an in-memory state of a shared counter as a singleton object that is shared between all concurrent instances, which demonstrates how easy it is to share information between different COM instances.
You can also run the VB-script Demo.Client.vbs that is located in the Demo.Client folder to see how it is possible to connect to the server from different langauages.
Now disconnect all clients. After a couple of seconds the Demo.Server process goes out of scope and is automatically shutdown again. You see it disappears in the Task Manager. If you start a new client the counter has been reset.
##Implement your own out-of-proc COM Server Follow along to create your own out-of-proc COM Server. Check out the Demo.Server project for helpful hints. ###Create a new project Create a new Windows Forms Application. You can delete the automatically created class Form1 unless you need it for something else. ###Register a COM factory Open Program.cs and locate the method signature static void Main(). Create and register a factory for creating your COM objects upon request.
var helloWorldFactory = new ClassFactory<HelloWorld, IHelloWorld>();
ComServer.Instance.Register<HelloWorld>(helloWorldFactory, CLSCTX.LOCAL_SERVER);
Where HelloWorld is the class you want to be created and IHelloWorld is the interface the client will see.
###Start the COM server Directly after registering the COM classes, you need to start the Com server.
ComServer.Instance.Run();
It is the ComServer instance that will receive and handle the actual requests for COM objects. The COM specification