Custom ServiceObject Question - SoType.File?????

OK, I think I figured this out.

Checking the class model for the SourceCode.SmartObjects.Services.ServiceSDK.Objects namespace I saw a FileProperty type. Use this declaration (make sure to use this constructor - see why with reflection):

            FileProperty fpropData = new FileProperty("FileData", new MetaData(), String.Empty, String.Empty);
            fpropData.MetaData.DisplayName = "File Data";
            fpropData.MetaData.Description = "File Data";
            this.Properties.Add(fpropData);

When it comes to assigning a value to ServiceBroker.ServicePackage.ResultTable.NewRow Item (during a Read/List operation), you have to encode your byte[] file content as Base64 and enclose it in XML.

I used this helper method to simplify the process:

        public static object ToFilePropertyValue(string propName, string filename, byte[] content)
        {
            return (new FileProperty(propName, new MetaData(), filename, Convert.ToBase64String(content))).Value;
        }

So the assignment operation looks like this: 

        dr["File"] = Helper.ToFilePropertyValue("File", "foobar.dat", {foobar byte[]});

It seems that Smart Object File properties hold the name and Base64 encoded content of the file. So, if in your process you need to store the content locally (at process level or activity level), use a String field.

Huge thanks goes out the mighty Lutz Roeder's .NET reflector. 

R