不能隱式轉換類型'System.Guid？'到'DataContracts.Market'

Question

我收到以下錯誤

不能隱式轉換類型'System.Guid？'以 'DataContracts.Market'

---

private CellSite MapEntityToCellSitePOCO(t_CellSite _cellsite) 
    { 

     CellSite cellsite= new CellSite(); 
     cellsite.SiteId = _cellsite.SiteID; 
     cellsite.Market.MarketID = _cellsite.MarketId; 
     cellsite.Region.RegionId = _cellsite.RegionId; 


     return cellsite; 
    } 

，以下是我datacontracts文件

---

public class CellSite 
{ 


    public Guid CellSiteID { get; set; } 

    public string SiteId { get; set; } 
    public Region Region { get; set; } 
    public Market Market { get; set; } 
    public Guid? ConstructionManager { get; set;} 
    } 

這是market.cs

 public class Market 
{ 
    public Guid? MarketID { get; set; } 
    public string OperatorMarketName { get; set; } 
    public string MarketName { get; set; } 
    public decimal AllOtherAmount { get; set; } 
    public decimal RawLandAmount { get; set; } 
    public decimal RenewalFee { get; set; } 
    public bool IsActive { get; set; } 
} 

有一列MarketId我想帶來的cellsite表，我可以這樣做嗎？我是新來的實體框架工作。 由於事先

Answer 1

你必須首先初始化Market和Region屬性：

CellSite cellsite= new CellSite(); 
cellsite.SiteId = _cellsite.SiteID; 

cellsite.Market = new Market(); 
cellsite.Market.MarketID = _cellsite.MarketId; 

cellsite.Region = new Region(); 
cellsite.Region.RegionId = _cellsite.RegionId;