Question

How do I create a C# event handler that can be handled in IronPython?

Note that I am using IronPython 2.0.1. I am able to handle events from system classes with no problems (eg Window.KeyDown) but when I try to define my own C# event an exception is raised when I attempt to hook it from IronPython.

The exception thrown is ArgumentTypeException and it has the message “cannot add to private event”. The message seems odd considering the event I am trying to hook is public.

My C# class looks like this:

class Foo
{
    ...

    public event EventHandler Bar;
}

My IronPython setup code looks like this:

ScriptEngine engine = Python.CreateEngine();
ScriptRuntime runtime = engine.Runtime;
ScriptScope scope = runtime.CreateScope();
ScriptSource source = engine.CreateScriptSourceFromFile("Test.py");
Foo bar = new Foo();
scope.SetVariable("Foo", bar);
source.Execute(scope); <-- Exception is thrown here.

My IronPython script looks like this:

def BarHandler(*args):
    pass

Foo.Bar += BarHandler

Does anyone know if I am doing this wrong?

Or is something wrong with IronPython?

Answer 1

I figured it out.

The class needs to be public as well as the event.

eg

public class Foo
{
   ...   

    public event EventHandler Bar;
}