Check if property has attribute

Question

Given a property in a class, with attributes - what is the fastest way to determine if it contains a given attribute? For example:

    [IsNotNullable]
    [I         


        

Answer 1

If you are using .NET 3.5 you might try with Expression trees. It is safer than reflection:

class CustomAttribute : Attribute { }

class Program
{
    [Custom]
    public int Id { get; set; }

    static void Main()
    {
        Expression> expression = p => p.Id;
        var memberExpression = (MemberExpression)expression.Body;
        bool hasCustomAttribute = memberExpression
            .Member
            .GetCustomAttributes(typeof(CustomAttribute), false).Length > 0;
    }
}