我在做什麼錯？ wcf＆entity-framework

Question

我剛剛遇到了WCF，並開始學習它。但是，一旦我嘗試將它與EntityFramework結合，它就停止工作。我爲我的數據庫dtcinvoicerdb創建了一個實體模型，關閉了代碼生成並自己編寫了Entity/ObjectContext類。該服務應該從數據庫中獲取所有Employees。

一切工作正常，項目編制和WcfTestClient打開了，但是當我嘗試調用GetEmployees()操作，我得到以下異常：

Mapping and metadata information could not be found for EntityType 'DtcInvoicerDbModel.Employee'. 

我知道有很多下面的代碼，但它的所有非常基本的，所以忍受着我。

entity image and model properties http://img716.imageshack.us/img716/1397/wcf.png

/Entities/DtcInvoicerDbContext.cs

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Text; 

using System.Data.Objects; 

using DtcInvoicerDbModel; 

namespace DtcInvoicerServiceLibrary 
{ 
    public class DtcInvoicerDbContext:ObjectContext 
    { 
     public DtcInvoicerDbContext():base("name=DtcInvoicerDbEntities", "DtcInvoicerDbEntities") 
     { 
     } 

     #region public ObjectSet<Employee> Employees; 
     private ObjectSet<Employee> _Employees; 
     public ObjectSet<Employee> Employees 
     { 
      get 
      { 
       return (_Employees == null) ? (_Employees = base.CreateObjectSet<Employee>("Employees")) : _Employees; 
      } 
     } 
     #endregion 
    } 
} 

/Entities/Employee.cs

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Text; 

using System.Data.Objects.DataClasses; 
using System.Runtime.Serialization; 

namespace DtcInvoicerDbModel 
{ 
    [DataContract] 
    public class Employee 
    { 
     [DataMember] 
     public int ID { get; set; } 
     [DataMember] 
     public string FirstName { get; set; } 
     [DataMember] 
     public string LastName { get; set; } 
     [DataMember] 
     public string Username { get; set; } 
     [DataMember] 
     public string Password { get; set; } 
     [DataMember] 
     public DateTime EmployeeSince { get; set; } 
    } 
} 

/IDtcInvoicerServicer.cs

個

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Text; 

using System.ServiceModel; 

using DtcInvoicerDbModel; 

namespace DtcInvoicerServiceLibrary 
{ 
    [ServiceContract] 
    public interface IDtcInvoicerService 
    { 
     [OperationContract] 
     List<Employee> GetEmployees(); 
    } 
} 

/DtcInvoicerService.cs

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Text; 

using System.ServiceModel; 

using DtcInvoicerDbModel; 

namespace DtcInvoicerServiceLibrary 
{ 
    [ServiceBehavior(InstanceContextMode=InstanceContextMode.Single, IncludeExceptionDetailInFaults=true)] 
    public class DtcInvoicerService:IDtcInvoicerService 
    { 
     private DtcInvoicerDbContext db = new DtcInvoicerDbContext(); 

     public List<Employee> GetEmployees() 
     { 
      return db.Employees.Where(x => x.ID > 0).ToList(); 
     } 
    } 
} 

Answer 1

我知道這並不能回答你的問題，但你的服務，你有沒有考慮過使用WCF Data Services呢？您的服務正在將您的實體返回給您的客戶端 - WCF數據服務可以爲您提供這些服務，同時也爲您的客戶提供使用LINQ查詢來過濾和/或投影結果的能力。

您可以添加一個WCF數據服務項目（InvoicerService.svc）到項目，併成立了像這樣的服務類：

public class InvoicerService : DataService<DtcInvoicerDbEntities> 
{ 
    public static void InitializeService(DataServiceConfiguration config) 
    { 
     config.SetEntitySetAccessRule("Employees", EntitySetRights.AllRead); 

     config.SetEntitySetPageSize("*", 25); 
     config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V2; 
    } 
} 

然後，您可以通過使用URL GET請求訪問你的員工：

http://server:port/InvoicerService.svc/Employees?$filter=ID gt 0 

再次，不是你的問題的答案，但也許是一種選擇。只是想我會添加它。

希望這會有所幫助！

Answer 2

稀釋了它經過一些搜索的計算器，用生成的代碼比較工作。

錯誤：我缺少一個屬性IsActive，我沒加EDM屬性的類和它的屬性。

對於遇到同樣問題的任何人，請記住在所有屬性上設置EdmScalarProperty（或其他屬性類型）屬性，並且不要忘記設置哪個屬性作爲EntityKey（例如ID）。

下面是我的Employee類現在的樣子，它的工作原理。

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Text; 

using System.Data.Objects.DataClasses; 
using System.Runtime.Serialization; 

[assembly: EdmSchemaAttribute()] 
namespace DtcInvoicerDbModel 
{ 
    [EdmEntityType(NamespaceName="DtcInvoicerDbModel", Name="Employee")] 
    [DataContract(IsReference=true)] 
    public class Employee 
    { 
     [DataMember] 
     [EdmScalarProperty(EntityKeyProperty = true, IsNullable = false)] 
     public int ID { get; set; } 

     [DataMember] 
     [EdmScalarProperty(EntityKeyProperty = false, IsNullable = false)] 
     public bool IsActive { get; set; } 

     [DataMember] 
     [EdmScalarProperty(EntityKeyProperty = false, IsNullable = false)] 
     public string FirstName { get; set; } 

     [DataMember] 
     [EdmScalarProperty(EntityKeyProperty = false, IsNullable = false)] 
     public string LastName { get; set; } 

     [DataMember] 
     [EdmScalarProperty(EntityKeyProperty = false, IsNullable = false)] 
     public string Username { get; set; } 

     [DataMember] 
     [EdmScalarProperty(EntityKeyProperty = false, IsNullable = false)] 
     public string Password { get; set; } 

     [DataMember] 
     [EdmScalarProperty(EntityKeyProperty = false, IsNullable = true)] 
     public DateTime? EmployeeSince { get; set; } 
    } 
}