Uncatcheable exception from MethodInfo.Invoke

Question

I have this code which Invokes a MethodInfo:

try
{
     registrator.Method.Invoke(instance, parameters);
}
catch{
    registrator.FailureType = RegistratorFailureType.ExceptionInRegistrator;
    //registrator.Exception = e;
}

The Registrator is just a MethodInfo wrapper, the Method property is the MethodInfo object itself. parameters is and object[] and instance is a correct instance of the Method's declaring type (created with Activator.Create).

The Method looks like this (I was testing exception catching):

class Test : Plugin, ITest
{
    public void Register(IWindow window)
    {
        throw new Exception("Hooah");
    }
}

The problem is: The exception is never caught and the Visual Studio's uncaught exception bubble pops up.

This is in VS 2010 with .NET 4.0

You could, perhaps, like, maybe, tell us what the exception is? — Timwi, Aug 30 '10 at 08:56
Can you produce a small, but complete, example program that exhibits the problem? — Lasse V. Karlsen, Aug 30 '10 at 09:03
which type registrator is instance of? Maybe the problem is in the catch clause (in FailureType or registrator is null) — onof, Aug 30 '10 at 09:07
@Timwi: TYou mean the uncaught exception? It is exactly what is thrown in the Register method: Exception type object with Message "Hooah" — Matěj Zábský, Aug 30 '10 at 09:09

score 2 · Accepted Answer · answered Aug 30 '10 at 10:08

2

The problem is not in your code anyway.
In the Debug/Exceptions menu, remove all checks.
It should work.

answered Aug 30 '10 at 10:08

Behrooz

1,696
2
32
54

Oh, thanks, this seems to solve my problem. Just one extra question: is this setting saved in project file or in user VS configuration (I mean, if someone else opens my project on his PC, will the exception be disabled there as well)? – Matěj Zábský Aug 30 '10 at 14:36
Ah thanks...thats what i was afraid of, I guess there is no way to circumvent this..? – Matěj Zábský Aug 30 '10 at 19:02

score 0 · Answer 2 · answered Aug 30 '10 at 09:07

0

Have you tried this?

In Program.cs

Application.ThreadException += new System.Threading.ThreadExceptionEventHandler(Application_ThreadException);

And a try/catch on the Run method:

try
{
    Application.Run(new Form1());
}
    catch (Exception ex)
{
}

answered Aug 30 '10 at 09:07

Jérémie Bertrand

3,025
3
44
53

The application is currently Console only. The code will be later used in WPF appplication though. – Matěj Zábský Aug 30 '10 at 09:48

score 0 · Answer 3 · answered Aug 30 '10 at 09:23

The problem is not with the code you're showing.

I tried this:

void Main()
{
    Test instance = new Test();
    object[] parameters = new object[] { null };

    MethodInfo method = typeof(Test).GetMethod("Register");

    try
    {
        method.Invoke(instance, parameters);
    }
    catch
    {
        Console.Out.WriteLine("Exception");
    }
}

interface ITest { }
interface IWindow { }
class Plugin { }

class Test : Plugin, ITest
{
    public void Register(IWindow window)
    {
        throw new Exception("Hooah");
    }
}

It printed "Exception" as expected. You need to show us more code.

If I modify the code like this:

catch(Exception ex)
{
    Console.Out.WriteLine(ex.GetType().Name + ": " + ex.Message);
}

Then I get a TargetInvocationException, where the InnerException property is your thrown Exception.

score 0 · Answer 4 · answered Aug 30 '10 at 09:40

I think the problem is that you are expecting a specific exception type, maybe IOException or something, but actually MethodInfo.Invoke() will throw a TargetInvocationException:

try
{
     registrator.Method.Invoke(instance, parameters);
}
catch (TargetInvocationException tie)
{
    // replace IOException with the exception type you are expecting
    if (tie.InnerException is IOException)
    {
        registrator.FailureType = RegistratorFailureType.ExceptionInRegistrator;
        registrator.Exception = tie.InnerException;
    }
    else
    {
        // decide what you want to do with all other exceptions — maybe rethrow?
        throw;
        // or maybe unwrap and then throw?
        throw tie.InnerException;
    }
}

Uncatcheable exception from MethodInfo.Invoke

4 Answers4

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