C# attribute text from resource file?

Here is my solution. I've added resourceName and resourceType properties to attribute, like microsoft has done in DataAnnotations.

public class CustomAttribute : Attribute
{

    public CustomAttribute(Type resourceType, string resourceName)
    {
            Message = ResourceHelper.GetResourceLookup(resourceType, resourceName);
    }

    public string Message { get; set; }
}

public class ResourceHelper
{
    public static  string GetResourceLookup(Type resourceType, string resourceName)
    {
        if ((resourceType != null) && (resourceName != null))
        {
            PropertyInfo property = resourceType.GetProperty(resourceName, BindingFlags.Public | BindingFlags.Static);
            if (property == null)
            {
                throw new InvalidOperationException(string.Format("Resource Type Does Not Have Property"));
            }
            if (property.PropertyType != typeof(string))
            {
                throw new InvalidOperationException(string.Format("Resource Property is Not String Type"));
            }
            return (string)property.GetValue(null, null);
        }
        return null; 
    }
}

Attribute values are hard-coded into the assembly when you compile. If you want to do anything at execution time, you'll need to use a constant as the key, then put some code into the attribute class itself to load the resource.

Here is the modified version of the one I put together:

[System.AttributeUsage(System.AttributeTargets.Class, AllowMultiple = false)]
public class ProviderIconAttribute : Attribute
{
    public Image ProviderIcon { get; protected set; }

    public ProviderIconAttribute(Type resourceType, string resourceName)
    {
        var value = ResourceHelper.GetResourceLookup<Image>(resourceType, resourceName);

        this.ProviderIcon = value;
    }
}

    //From http://stackoverflow.com/questions/1150874/c-sharp-attribute-text-from-resource-file
    //Only thing I changed was adding NonPublic to binding flags since our images come from other dll's
    // and making it generic, as the original only supports strings
    public class ResourceHelper
    {
        public static T GetResourceLookup<T>(Type resourceType, string resourceName)
        {
            if ((resourceType != null) && (resourceName != null))
            {
                PropertyInfo property = resourceType.GetProperty(resourceName, BindingFlags.Public | BindingFlags.Static | BindingFlags.NonPublic);
                if (property == null)
                {
                    return default(T);
                }

                return (T)property.GetValue(null, null);
            }
            return default(T);
        }
    }