Question

Looking for a clean way to discover the string name of a method in a type safe way.

Here is what I have for properties, but I’m having trouble figuring out how to do it for methods.

class Program
{
    class Customer
    {
        public String Id { get; set; }
    }

    public static String GetPropertyName<T>(
        Expression<Func<T, Object>> selector) where T : class
    {
        var expression = (MemberExpression)selector.Body;
        return expression.Member.Name;
    }

    static void Main(string[] args)
    {
        String propertyName = GetPropertyName<Customer>(c => c.Id);
    }
}

Answer 1

Pretty much by changing to:

    var expression = (MethodCallExpression)selector.Body;
    return expression.Method.Name;

with the notable exception that you will need an Action<T> option to handle void methods. You will have to supply dummy parameter values, of course – if you really want you can obtain those too.

Actually, your existing code might not be robust; you may need to throw away a cast operation (to box the int to an object).

public static string GetMethodName<T>(Expression<Func<T, Object>> selector) where T : class
{
    var expression = (MethodCallExpression)(selector.Body is UnaryExpression ? ((UnaryExpression)selector.Body).Operand : selector.Body);
    return expression.Method.Name;
}
public static string GetMethodName<T>(Expression<Action<T>> selector) where T : class
{
    var expression = (MethodCallExpression)(selector.Body is UnaryExpression ? ((UnaryExpression)selector.Body).Operand : selector.Body);
    return expression.Method.Name;
}