Invoke method by MethodInfo

Question

I want to invoke methods with a certain attribute. So I'm cycling through all the assemblies and all methods to find the methods with my attribute. Works fine, but how do I invoke a certain method when I only got it's MethodInfo.

AppDomain app = AppDomain.CurrentDomain;
Assembly[] ass = app.GetAssemblies();
Type[] types;
foreach (Assembly a in ass)
{
    types = a.GetTypes();
    foreach (Type t in types)
    {
        MethodInfo[] methods = t.GetMethods();
        foreach (MethodInfo method in methods)
        {
            // Invoke a certain method
        }
    }
}

The problem is that I don't know the instance of the class that contains that certain method. So I can't invoke it properly because the methods are not static. I also want to avoid creating a new instance of this class if possible.

Answer 1

Non-static methods are instance specific so you must instantiate the class to invoke the method. If you have the ability to change the code where it is defined and the method doesn't require itself to be part of an instance (it doesn't access or modify any non-static properties or methods inside the class) then best practice would be to make the method static anyway.

Assuming you can't make it static then the code you need is as follows:

    foreach (Type t in types)
    {
            object instance = Activator.CreateInstance(t);

            MethodInfo[] methods = t.GetMethods();
            foreach (MethodInfo method in methods)
            {                    
                method.Invoke(instance, params...);    
            }
    }