MvvmCross MethodBinding extensions for fluent syntax

MethodBindingExtensions.cs

    public static class MethodBindingExtensions
    {
        public static MvxFluentBindingDescription<TTarget, TSource> ToMethod<TTarget, TSource>(this MvxFluentBindingDescription<TTarget, TSource> description, Expression<Func<TSource, Action>> method) where TTarget : class
        {
            var name = FindMethodName(method);
            return description.To(name);
        } 
        public static MvxFluentBindingDescription<TTarget, TSource> ToMethod<TTarget, TSource>(this MvxFluentBindingDescription<TTarget, TSource> description, Expression<Func<TSource, Func<Task>>> method) where TTarget : class
        {
            var name = FindMethodName(method);
            return description.To(name);
        }

        private static string FindMethodName(LambdaExpression method)
        {
            var body = method.Body as UnaryExpression;
            if (body == null)
                throw new ArgumentException("Method body must be UnaryExpression");
            var operand = body.Operand as MethodCallExpression;
            if (operand == null)
                throw new ArgumentException("Method body's operand must be MethodCallExpression");
            if (operand.Arguments.Count < 3)
                throw new ArgumentException("Method body's operand should have 3 arguments");
            var argument = operand.Arguments[2] as ConstantExpression;
            if (argument == null)
                throw new ArgumentException("Method body's operand's third argument should be ConstantExpression");
            var methodInfo = argument.Value as MethodInfo;
            if (methodInfo == null)
                throw new ArgumentException("Method body's operand's third argument should have a MethodInfo as Value");
            var name = methodInfo.Name;
            return name;
        }
    }