获取Func变量

我有一个相当复杂的问题。我试图从一个方法和它的形式和实际参数得到一个唯一的关键。方法的目标是接受一个方法调用，并根据以下条件返回一个唯一键:1)类和方法的名称;2)调用它的参数的名称和值。

方法看起来像这样(抱歉所有的细节，但我找不到一个明智的方法，使示例更小，但仍然解释我的问题)

 public class MethodKey
    {
        public static string GetKey<T>(Expression<Func<T>> method, params string[] paramMembers)
        {
            var keys = new Dictionary<string, string>();
            string scope = null;
            string prefix = null;
            ParameterInfo[] formalParams = null;
            object[] actual = null;
            var methodCall = method.Body as MethodCallExpression;
            if (methodCall != null)
            {
                scope = methodCall.Method.DeclaringType.FullName;
                prefix = methodCall.Method.Name;
                IEnumerable<Expression> actualParams = methodCall.Arguments;
                actual = actualParams.Select(GetValueOfParameter<T>).ToArray();
                formalParams = methodCall.Method.GetParameters();
            }
            else
            {
                // TODO: Check if the supplied expression is something that makes sense to evaluate as a method, e.g. MemberExpression (method.Body as MemberExpression)
                var objectMember = Expression.Convert(method.Body, typeof (object));
                var getterLambda = Expression.Lambda<Func<object>>(objectMember);
                var getter = getterLambda.Compile();
                var m = getter();

                var m2 = ((System.Delegate) m);
                var delegateDeclaringType = m2.Method.DeclaringType;
                var actualMethodDeclaringType = delegateDeclaringType.DeclaringType;
                scope = actualMethodDeclaringType.FullName;
                var ar = m2.Target;
                formalParams = m2.Method.GetParameters();
                //var m = (System.MulticastDelegate)((Expression.Lambda<Func<object>>(Expression.Convert(method.Body, typeof(object)))).Compile()())
                //throw new ArgumentException("Caller is not a method", "method");
            }

            // null list of paramMembers should disregard all parameters when creating key.
            if (paramMembers != null)
            {
                for (var i = 0; i < formalParams.Length; i++)
                {
                    var par = formalParams[i];
                    // empty list of paramMembers should be treated as using all parameters 
                    if (paramMembers.Length == 0 || paramMembers.Contains(par.Name))
                    {
                        var value = actual[i];
                        keys.Add(par.Name, value.ToString());
                    }
                }
                if (paramMembers.Length != 0 && keys.Count != paramMembers.Length)
                {
                    var notFound = paramMembers.Where(x => !keys.ContainsKey(x));
                    var notFoundString = string.Join(", ", notFound);
                    throw new ArgumentException("Unable to find the following parameters in supplied method: " + notFoundString, "paramMembers");
                }
            }
            return scope + "¤" + prefix +  "¤" + Flatten(keys);
        }

        private static object GetValueOfParameter<T>(Expression parameter)
        {
            LambdaExpression lambda = Expression.Lambda(parameter);
            var compiledExpression = lambda.Compile();
            var value = compiledExpression.DynamicInvoke();
            return value;
        }
}

然后，我有下面的测试，它工作正常:

        [Test]
        public void GetKey_From_Expression_Returns_Expected_Scope()
        {
            const string expectedScope = "MethodNameTests.DummyObject";
            var expected = expectedScope + "¤" + "SayHello" + "¤" + MethodKey.Flatten(new Dictionary<string, string>() { { "name", "Jens" } });
            var dummy = new DummyObject();
            var actual = MethodKey.GetKey(() => dummy.SayHello("Jens"), "name");
            Assert.That(actual, Is.Not.Null);
            Assert.That(actual, Is.EqualTo(expected));
        }

但是，如果我将() => dummy.SayHello("Jens")调用放在一个变量中，则调用失败。因为我不再在我的GetKey方法中获得MethodCallExpression，而是FieldExpression (MemberExpression的子类)。测试是:

        [Test]
        public void GetKey_Works_With_func_variable()
        {
            const string expectedScope = "MethodNameTests.DummyObject";
            var expected = expectedScope + "¤" + "SayHello" + "¤" + MethodKey.Flatten(new Dictionary<string, string>() { { "name", "Jens" } });
            var dummy = new DummyObject();
            Func<string> indirection = (() => dummy.SayHello("Jens"));
            // This fails. I would like to do the following, but the compiler
            // doesn't agree :)
            // var actual = MethodKey.GetKey(indirection, "name");
            var actual = MethodKey.GetKey(() => indirection, "name");
            Assert.That(actual, Is.Not.Null);
            Assert.That(actual, Is.EqualTo(expected));
        }

Dummy类SayHello方法定义是琐碎的:

 public class DummyObject
    {
        public string SayHello(string name)
        {
            return "Hello " + name;
        }
        public string Meet(string person1, string person2 )
        {
            return person1 + " met " + person2;
        }
    }

我有两个问题:

1. 是否有办法将变量indirection发送到MethodKey.GetKey，并将其作为MethodCallExpression类型?
2. 如果不是，我怎么能得到的名称和值提供的方法，如果我得到一个MemberExpression代替?我在代码的"else"部分尝试了一些，但没有成功。

任何帮助都是感激的。

提前表示感谢，很抱歉发了这么长时间。

Expression<Func<string>> foo = () => dummy.SayHello("Jens");
var actual = MethodKey.GetKey<string>(foo, "name");