复制实体框架对象 [英] Copy Entity Framework Object

问题描述

我有一个EF4.1 X类，我想打的副本及其所有子记录。
XY和XYZ

现在，如果我做了以下则返回错误。

属性 X.ID'是对象的关键信息的一部分，不能修改。

 公共无效CopyX（长ID）
 {
变种C = db.Xs.Include（Y）包含（W）包含（YZ）的SingleOrDefault（X => x.ID == ID）。。。; 
如果（C！= NULL）
 {
 c.ID = 0; 
 c.Title =复制+ c.Title; 
为（VAR M = 0; M< c.Ys.Count; M +）
 {
 c.Ys [M] .ID = 0; 
 c.Ys [M]。.XID = 0米; 
为（VAR P = 0; P< c.Ys [M]。.Zs.Count，P ++）
 {
 c.Ys [M]。.Zs ​​[P] .XID = 0  - 米; 
 c.Ys [M]。.Zs ​​[P] .ID = 0  -  P; 
} 
} 
为（VAR I = 0; I< c.Ws.Count;我++）
 {
 c.Ws [I] .ID = 0  - 我; 
 c.Ws [I] .XID = 0; 
} 
 db.Entry<内容>（三）.STATE = System.Data.EntityState.Added; 
 db.SaveChanges（）; 
} 
} 
  

或有做实体对象的副本的其他途径。

请注意：有每个W2多重特性，X，Y，Z

解决方案<。 / DIV>

您需要使整个实体图的正确深拷贝 - 最好的办法是序列原始实体图形内存流，并将其反序列化到一个新的实例。你的实体必须是可序列化。它经常与DataContractSerializer的使用但您可以使用二进制序列化以及。

I have a EF4.1 class X and I want to make copy of that plus all its child records. X.Y and X.Y.Z

Now if I do the following it returns error.

The property 'X.ID' is part of the object's key information and cannot be modified.

public void CopyX(long ID)
{
    var c = db.Xs.Include("Y").Include("W").Include("Y.Z").SingleOrDefault(x => x.ID == ID);
    if (c != null)
    {
        c.ID = 0;
        c.Title = "Copy Of " + c.Title;
        for (var m = 0; m < c.Ys.Count; m++)
        {
            c.Ys[m].ID = 0;
            c.Ys[m].XID=0-m;
            for (var p = 0; p < c.Ys[m].Zs.Count; p++)
            {
                c.Ys[m].Zs[p].XID = 0 - m;
                c.Ys[m].Zs[p].ID = 0 - p;
            }
        }
        for (var i = 0; i < c.Ws.Count; i++)
        {
            c.Ws[i].ID = 0 - i;
            c.Ws[i].XID = 0;
        }
        db.Entry<Content>(c).State = System.Data.EntityState.Added;
        db.SaveChanges();
    }
}

Or Is there other way of making copy of entity objects.

NOTE: there are multiple properties in each W,X,Y,Z.

解决方案

You need to make correct deep copy of the whole entity graph - the best way is to serialize the original entity graph to memory stream and deserialize it to a new instance. Your entity must be serializable. It is often used with DataContractSerializer but you can use binary serialization as well.

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