Entity Framework 4 többrétegű appokban – Microsoft technologies by Zsolt Soczo

Játszottam kicsit az EF4-gyel. Az alábbi kód egy n rétegű app adatmozgását szimulálja a WCF xml szerializálóját használva. Mindhárom template-tel kipróbáltam, alább láthatóak az adatmozgások.
A tesztkód messze nem korrekt, de kiindulópontként további vizsgálatokhoz elfogatható:

using System;
using System.IO;
using System.Linq;
using System.Runtime.Serialization;

namespace POCO1
{
class Program
{
static void Main()
{
Department d;
using (var e = new SchoolEntities())
{
e.ContextOptions.ProxyCreationEnabled = false;
e.ContextOptions.LazyLoadingEnabled = false;
d = e.Departments.Include(“Courses”).Single(dep => dep.DepartmentID == 1);
Console.WriteLine(“{0}”, d.Name);
Console.WriteLine(“———————“);
foreach (Course c in d.Courses)
{
Console.WriteLine(“{0}”, c.Title);
}
e.Detach(d);
}

var ser = new DataContractSerializer(d.GetType());
//var ser = new DataContractSerializer(d.GetType(),
//null, 50000, true, true, null, new ProxyDataContractResolver());

using (var s2c = new FileStream(@”c:\temp\Server2Client.xml”, FileMode.Create, FileAccess.ReadWrite))
{
//1. Server küld kliensre
ser.WriteObject(s2c, d);
s2c.Position = 0;
//2. Kliens deserializál
var clientSideDep = (Department)ser.ReadObject(s2c);

//Csak ST
//bool ce = clientSideDep.ChangeTracker.ChangeTrackingEnabled;

//3. Kliens módosít
clientSideDep.Name += “a”;

using (var c2s = new FileStream(@”c:\temp\Client2Server.xml”, FileMode.Create, FileAccess.ReadWrite))
{
//4. Kliens visszaküld
ser.WriteObject(c2s, clientSideDep);
c2s.Position = 0;

//5.Server deserializál
var sentBackDepartment = (Department)ser.ReadObject(c2s);
using (var e = new SchoolEntities())
{
//6. Server visszamódosít

//Normál entitás
e.Departments.Attach(sentBackDepartment);
e.ObjectStateManager.GetObjectStateEntry(sentBackDepartment).SetModified();
e.ObjectStateManager.GetObjectStateEntry(sentBackDepartment).SetModifiedProperty(“Name”);

//POCO
//e.Departments.Include(“Courses”).Single(dep => dep.DepartmentID == 1);
//e.Departments.ApplyCurrentValues(sentBackDepartment);

//Self-tracking entity
//e.Departments.ApplyChanges(sentBackDepartment);

e.SaveChanges();
}
}
}
}
}
}

EF alapobjektumok szerviz => kliens:

<Department z:Id="i1" xmlns="http://schemas.datacontract.org/2004/07/POCO1" xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns:z="http://schemas.microsoft.com/2003/10/Serialization/">
  <EntityKey z:Id="i2" xmlns="http://schemas.datacontract.org/2004/07/System.Data.Objects.DataClasses" xmlns:a="http://schemas.datacontract.org/2004/07/System.Data">
    <a:EntityContainerName>SchoolEntities</a:EntityContainerName>
    <a:EntityKeyValues>
      <a:EntityKeyMember>
        <a:Key>DepartmentID</a:Key>
        <a:Value i:type="b:int" xmlns:b="http://www.w3.org/2001/XMLSchema">1</a:Value>
      </a:EntityKeyMember>
    </a:EntityKeyValues>
    <a:EntitySetName>Departments</a:EntitySetName>
  </EntityKey>
  <Administrator>2</Administrator>
  <Budget>350000.0000</Budget>
  <Courses/>
  <DepartmentID>1</DepartmentID>
  <Name>Engineering</Name>
  <StartDate>2007-09-01T00:00:00</StartDate>
</Department>

EF alapobjektumok kliens => szerviz:

<Department z:Id="i1" xmlns="http://schemas.datacontract.org/2004/07/POCO1" xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns:z="http://schemas.microsoft.com/2003/10/Serialization/">
  <EntityKey z:Id="i2" xmlns="http://schemas.datacontract.org/2004/07/System.Data.Objects.DataClasses" xmlns:a="http://schemas.datacontract.org/2004/07/System.Data">
    <a:EntityContainerName>SchoolEntities</a:EntityContainerName>
    <a:EntityKeyValues>
      <a:EntityKeyMember>
        <a:Key>DepartmentID</a:Key>
        <a:Value i:type="b:int" xmlns:b="http://www.w3.org/2001/XMLSchema">1</a:Value>
      </a:EntityKeyMember>
    </a:EntityKeyValues>
    <a:EntitySetName>Departments</a:EntitySetName>
  </EntityKey>
  <Administrator>2</Administrator>
  <Budget>350000.0000</Budget>
  <Courses/>
  <DepartmentID>1</DepartmentID>
  <Name>Engineeringa</Name>
  <StartDate>2007-09-01T00:00:00</StartDate>
</Department>

POCO szerviz => kliens:

<Department xmlns="http://schemas.datacontract.org/2004/07/POCO1" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
  <Administrator>2</Administrator>
  <Budget>350000.0000</Budget>
  <Courses/>
  <DepartmentID>1</DepartmentID>
  <Name>Engineeringa</Name>
  <StartDate>2007-09-01T00:00:00</StartDate>
</Department>

POCO kliens => szerviz:

2
350000.0000

1
Engineeringaa
2007-09-01T00:00:00

Self-tracking entity, szerviz => kliens:

<Department z:Id="i1" xmlns="http://schemas.datacontract.org/2004/07/POCO1" xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns:z="http://schemas.microsoft.com/2003/10/Serialization/">
  <Administrator>2</Administrator>
  <Budget>350000.0000</Budget>
  <ChangeTracker z:Id="i2">
    <ExtendedProperties/>
    <ObjectsAddedToCollectionProperties/>
    <ObjectsRemovedFromCollectionProperties/>
    <OriginalValues/>
    <State>Unchanged</State>
  </ChangeTracker>
  <Courses/>
  <DepartmentID>1</DepartmentID>
  <Name>Engineeringaaaaaaaa</Name>
  <StartDate>2007-09-01T00:00:00</StartDate>
</Department>

Self-tracking entity, kliens => szerviz:

<Department z:Id="i1" xmlns="http://schemas.datacontract.org/2004/07/POCO1" xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns:z="http://schemas.microsoft.com/2003/10/Serialization/">
  <Administrator>2</Administrator>
  <Budget>350000.0000</Budget>
  <ChangeTracker z:Id="i2">
    <ExtendedProperties/>
    <ObjectsAddedToCollectionProperties/>
    <ObjectsRemovedFromCollectionProperties/>
    <OriginalValues/>
    <State>Modified</State>
  </ChangeTracker>
  <Courses/>
  <DepartmentID>1</DepartmentID>
  <Name>Engineeringaaaaaaaaa</Name>
  <StartDate>2007-09-01T00:00:00</StartDate>
</Department>

Érdekes, hogy a módosítás ténye csak a ST-ben látszik, még az eredeti entity-sben sem. A POCO-tól nem is vártuk persze.
Később még majd foglalkozok bővebben a témával. Aki játszani akar vele, hozza létre a School EF példaadatbázist, azon lehet futtatni.

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