错误Missingtypemapconfigurationorunsupportedmapping.Mappingtypes:Cities_C391BA93C06F35100522AFBFA8F6BF3823972C9E97D5A49783829A4E90A03F00->IEnumerable`1System.Data.Entity.DynamicProxies.Cities_C391BA93C06F35100522AFBFA8F6BF3823972C9E97D5A49783829A4E90A03F00->System.Collections.Generic.IEnumerable`1