C# Get Delegate from MethodInfo

Question

I have a problem with this code :

public static Delegate[] ExtractMethods(object obj)
{
    Type type = obj.GetType();
    MethodInfo[] methods = type.GetMethods(BindingFlags.Instance | BindingFlags.Public | BindingFlags.DeclaredOnly);
    Delegate[] methodsDelegate = new Delegate[methods.Count()];

    for (int i = 0; i < methods.Count(); i++)
    {
        methodsDelegate[i] = Delegate.CreateDelegate(null, methods[i]);
    }
    return methodsDelegate;
}

at Delegate.CreateDelegate delegate type most drived but I call this method for several objects. How to get delegate type ?

score 5 · Accepted Answer · edited May 23 '17 at 12:33

It worked for me. [ https://stackoverflow.com/a/16364220/1559611 ]

    public static Delegate[] ExtractMethods(object obj)
    {
        Type type = obj.GetType();

        MethodInfo[] methods = type.GetMethods(BindingFlags.Instance | BindingFlags.Public | BindingFlags.DeclaredOnly);

        Delegate[] methodsDelegate = new Delegate[methods.Count()];

        for (int i = 0; i < methods.Count(); i++)
        {
            methodsDelegate[i] = CreateDelegate(obj , methods[i]);
        }

        return methodsDelegate;
    }

    public static Delegate CreateDelegate(object instance, MethodInfo method)
    {
        var parameters = method.GetParameters()
                   .Select(p => Expression.Parameter(p.ParameterType, p.Name))
                    .ToArray();

        var call = Expression.Call(Expression.Constant(instance), method, parameters);
        return Expression.Lambda(call, parameters).Compile();
    }

On same lines as this one: http://stackoverflow.com/a/16364220/1559611 — Mrinal Kamboj, Oct 14 '16 at 06:52

score 1 · Answer 2 · answered Oct 14 '16 at 05:59

1

Use MethodInfo.DeclaringType

Type type = methods[0].DeclaringType;

you will have to be bit careful if you are using inheritance.

Also have a look at MethodInfo.ReflectedType

answered Oct 14 '16 at 05:59

Miguel Sanchez

434
3
11

I get error for both -> Type must derive from Delegate. – moien Oct 14 '16 at 06:08
@moien at which line are you getting the error I have tested this code and it is working for me – Miguel Sanchez Oct 14 '16 at 06:10
methodsDelegate[i] = Delegate.CreateDelegate(methods[i].DeclaringType, methods[i]); – moien Oct 14 '16 at 06:17
at Line 7 methodsDelegate[i] = Delegate.CreateDelegate(methods[i].DeclaringType, methods[i]); – moien Oct 14 '16 at 06:22
@moien sorry! a mistake the type you pass in a not of the Class Type but of the delegate type will update my answer shortly – Miguel Sanchez Oct 14 '16 at 06:32

C# Get Delegate from MethodInfo

2 Answers2