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c#javascript.netcom-interopidispatch

Passing an IDispatch parameter from C#

I'm writing a C# COM dll that will be used by both Managed C# as well as Delphi and C++ programs and javascript. The COM dll includes a monitor part where the application registers a function that is supposed to return a string value to the dll. I have done this before for javascript 'applications' where you would simply pass a function as a parameter to the dll. When the dll needs to query the javascript 'application' the following is run:

Type t = theScript.GetType();
object ret = t.InvokeMember("", BindingFlags.InvokeMethod, null, theScript, new object[] { });

'theScript' is stored as an Object in the C# dll. As far as I understand this is accomplished by IDispatch. My theory now is that I should be able to use the same approach for the other languages. So I made a COM visible method with this signature:

void RegisterQuery(object method);

However I can't figure out how to pass a parameter to this method from C#. I've tried using a delegate but calling the delegate simply returns the ToString() method from the delegate (the one that returns the calss name). Nothing else that I have tried even compiles.

So I have two questions:

  1. How shall I pass a method parameter to this dll from C# so that the dll will be able to call the methods, in the manner specified above, when it needs to?
  2. Is this really IDispatch or is there another reason why it works for javascript?

Thanks in advance

Solution

  • Turns out that this was really simple:

    Type t = theScript.GetType();
object ret = t.InvokeMember(theObject, BindingFlags.InvokeMethod, null, theScriptName, new object[] { });