C#反射调用私有方法

public object CallNonPublicMethod(object instance, string methodName, object[] param)
        {
            Type type = instance.GetType();
            MethodInfo method = type.GetMethod(methodName, BindingFlags.Instance | BindingFlags.NonPublic);
            object result;
            try
            {
                result = method.Invoke(instance, param);
            }
            catch (TargetInvocationException ex)
            {
                throw ex.InnerException;
            }
            return result;
        }