UDI and ContentService / GetValue

Using the contentpicker2 with the UDI. Need to grab the selected content item in an eventhandler with ContentService or IContent.GetValue<> but there doesnt seam to any propertyvalueconverters or methods that can use the UDI that is stored.

        string test = umb://document/53d62b4d52d2414fb0882d263cfd6e85;
        var udi = Udi.Parse(test);
        var page = Services.ContentService.GetById(udi);**

this code is error.please help me.