無法創建“Sunlight.Silverlight.Dcs.Web.PartsSupplier”類型的常量值。此上下文僅支持基元類型或枚舉類型問題

  今天寫代碼遇到一個問題，
            const string SCODE = "123";
            var suppliers = PartsSuppliers.Where(r => r.Code == SCODE).ToArray();
            var spares = from  spare in SpareParts
                         join partsSupplierRelation in PartsSupplierRelations on spare.Id equals partsSupplierRelation.PartId
                         join sup in suppliers on  partsSupplierRelation.SupplierId equals sup.Id
                         select spare;
            spares.Dump();

這樣回報一個錯誤，無法創建“Sunlight.Silverlight.Dcs.Web.PartsSupplier”類型的常量值。此上下文僅支持基元類型或枚舉類型問題

改成下面這樣就好了

          var spares = from sup in suppliers
                        join partsSupplierRelation in PartsSupplierRelations on sup.Id equals partsSupplierRelation.SupplierId
                        join spare in SpareParts on partsSupplierRelation.PartId equals spare.Id
                        select spare;
           spares.Dump();

不知道為什么，先記下來等有時間再去理解。