blocks|key|730469|text|您可以通过ObjectStateEntry访问它们|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|730470|var+originalValues+=+context
+++++++++.ObjectStateManager.GetObjectStateEntry(myEntity).OriginalValues;|code-block|syntax|javascript|730471|entityMap|0|LINK|mutability|MUTABLE|url|http://msdn.microsoft.com/en-us/library/system.data.objects.objectstateentry.aspx^0|5|G|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@$A|R|B|S|1|T]]|C|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|C|$G|H]]|$1|I|3|-4|5|6|7|V|8|@]|9|@]|C|$]]]|J|$K|$5|L|M|N|C|$O|P]]]]

You can access them through <a href="http://msdn.microsoft.com/en-us/library/system.data.objects.objectstateentry.aspx" rel="noreferrer">ObjectStateEntry</a>

<pre><code>var originalValues = context
 .ObjectStateManager.GetObjectStateEntry(myEntity).OriginalValues;
</code></pre>

blocks|key|514112|text|@Eranga的答案对于EF+5来说是过时的。由于某些原因，EF+5在使用如下语句获取原始值时不能正常工作：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|514113|var+originalValues+=+context.Entry(myEntity).OriginalValues;|code-block|syntax|javascript|514114|我的工作解决方案使用来自DbSet的AsNoTracking()方法，如下例所示：|offset|length|style|CODE|514115|var+originalEntity+=+context.MyEntities.AsNoTracking().FirstOrDefault(me+=>+me.MyEntityID+==+myEntity.MyEntityID);|514116|entityMap^0|0|0|C|5|I|E|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@$I|T|J|U|K|L]|$I|V|J|W|K|L]]|9|@]|A|$]]|$1|M|3|N|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|O|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|P|$]]

@Eranga answer is outdated for EF 5. For some reason, EF 5 doesn't work fine when getting original values using an statement like this:



<pre class="lang-cs prettyprint-override"><code>var originalValues = context.Entry(myEntity).OriginalValues;
</code></pre>

My working solution uses <code>AsNoTracking()</code> method from <code>DbSet</code>, like the example below:

<pre class="lang-cs prettyprint-override"><code>var originalEntity = context.MyEntities.AsNoTracking().FirstOrDefault(me =&gt; me.MyEntityID == myEntity.MyEntityID);
</code></pre>

blocks|key|730528|text|这可以进一步细化到以下内容：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|730529|var+originalEntity+=+context.MyEntities.AsNoTracking()
+++++++++.FirstOrDefault(me+=>+me.MyEntityID+==+myEntity.MyEntityID);|code-block|syntax|javascript|730530|上面的Where很好，不需要响应。|offset|length|style|CODE|730531|entityMap^0|0|0|3|5|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@$I|R|J|S|K|L]]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

This could be refined further to the following:

<pre class="lang-c# prettyprint-override"><code>var originalEntity = context.MyEntities.AsNoTracking()
 .FirstOrDefault(me =&gt; me.MyEntityID == myEntity.MyEntityID);
</code></pre>

The <code>Where</code> in the above, good, response is not needed.

blocks|key|514417|text|var+originalEntity+=+(EntityType)context.Entry(editEntity).OriginalValues.ToObject();|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|514418|对不起，我的英语不好。通过这种方式，您可以获得对象实体形式的原始实体值，而无需更改编辑值。|unstyled|514419|示例:如果您希望编辑一个人，则顶部的行将如下所示|514420|var+originalPerson+=+(Person)context.Entry(editPerson).OriginalValues.ToObject();|514421|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|N|8|@]|9|@]|A|$]]|$1|G|3|H|5|F|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|P|8|@]|9|@]|A|$B|C]]|$1|K|3|-4|5|F|7|Q|8|@]|9|@]|A|$]]]|L|$]]

<pre><code>var originalEntity = (EntityType)context.Entry(editEntity).OriginalValues.ToObject();
</code></pre>
Sorry for my english.
With this way you can get the original entity values in the form of the object entity with no changes on the edit values.
Example:
If you like edit a Person the line in top look like this
<pre><code>var originalPerson = (Person)context.Entry(editPerson).OriginalValues.ToObject();
</code></pre>

blocks|key|514217|text|我遇到了类似的问题，AsNoTracking不适合我的情况，所以我想出了一个对我来说足够好的方法:首先“克隆”实体，然后进行更改。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|514218|public+T+Clone<T>(T+entity)
++where+T+:+class,+new()+{

++var+clone+=+new+T();

++var+properties+=+typeof(T).GetProperties(BindingFlags.Public+%7C+BindingFlags.Instance+%7C+BindingFlags.FlattenHierarchy)
++++.Where(a+=>+a.CanRead+&&+
++++++++++++++++a.CanWrite+&&
++++++++++++++++a.GetMethod.IsFinal);

++foreach+(var+property+in+properties)+{+++++++
++++property.SetValue(clone,+property.GetValue(entity));
++}

++return+clone;
}|code-block|syntax|javascript|514219|然后将克隆与更改后的克隆进行比较。|514220|public+string+GenerateChangeText<T>(T+original,+T+current)
++where+T+:+class,+new()+{

++var+properties+=+typeof(T).GetProperties(BindingFlags.Public+%7C+BindingFlags.Instance+%7C+BindingFlags.FlattenHierarchy)
++++.Where(a+=>+a.CanRead+&&
++++++++++++++++a.CanWrite+&&
++++++++++++++++a.GetMethod.IsFinal);

++var+changes+=+string.Empty;

++foreach+(var+property+in+properties)+{

++++var+originalValue+=+property.GetValue(original);
++++var+currentValue+=+property.GetValue(current);

++++if+(originalValue+==+null+&&+currentValue+==+null)+continue;
++++if+((originalValue+!=+null+&&+!originalValue.Equals(currentValue))+%7C%7C
+++++++(currentValue+!=+null+&&+!currentValue.Equals(originalValue)))+{

++++++changes+%2B=+$"+changed+{property}+from+{original+??+"NULL"}+to+{current+??+"NULL"}.";
++++}
++}

++return+changes;
}|514221|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

I ran into a similar problem and AsNoTracking was not an option for my situation so i came up with something that works well enough for me: first "clone" the entity then do changes.

<pre><code>public T Clone&lt;T&gt;(T entity)
 where T : class, new() {

 var clone = new T();

 var properties = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance | BindingFlags.FlattenHierarchy)
 .Where(a =&gt; a.CanRead &amp;&amp; 
 a.CanWrite &amp;&amp;
 a.GetMethod.IsFinal);

 foreach (var property in properties) { 
 property.SetValue(clone, property.GetValue(entity));
 }

 return clone;
}
</code></pre>

and then compare the clone to the changed.

<pre><code>public string GenerateChangeText&lt;T&gt;(T original, T current)
 where T : class, new() {

 var properties = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance | BindingFlags.FlattenHierarchy)
 .Where(a =&gt; a.CanRead &amp;&amp;
 a.CanWrite &amp;&amp;
 a.GetMethod.IsFinal);

 var changes = string.Empty;

 foreach (var property in properties) {

 var originalValue = property.GetValue(original);
 var currentValue = property.GetValue(current);

 if (originalValue == null &amp;&amp; currentValue == null) continue;
 if ((originalValue != null &amp;&amp; !originalValue.Equals(currentValue)) ||
 (currentValue != null &amp;&amp; !currentValue.Equals(originalValue))) {

 changes += $" changed {property} from {original ?? "NULL"} to {current ?? "NULL"}.";
 }
 }

 return changes;
}
</code></pre>

blocks|key|730643|text|在使用中的实体框架有几个版本。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|730644|我自己更喜欢Code+First，有了这个API，就很容易做到|730645|_context.Entry(Entity).Reload();|code-block|syntax|javascript|730646|文档https://msdn.microsoft.com/en-us/library/system.data.entity.infrastructure.dbentityentry.reload(v=vs.103).aspx|offset|length|730647|较旧的应用程序接口在ObjectContext上有一个刷新方法，在某些用例中可以提供帮助|730648|ObjectContext.Refresh(RefreshMode.StoreWins,+Entity);|730649|文档https://msdn.microsoft.com/en-us/library/bb896255(v=vs.110).aspx|730650|entityMap|0|LINK|mutability|MUTABLE|url|https://msdn.microsoft.com/en-us/library/system.data.entity.infrastructure.dbentityentry.reload(v=vs.103).aspx|1|https://msdn.microsoft.com/en-us/library/bb896255(v=vs.110).aspx^0|0|0|0|2|32|0|0|0|0|2|1S|1|0^^$0|@$1|2|3|4|5|6|7|12|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|13|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|14|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|15|8|@]|9|@$K|16|L|17|1|18]]|A|$]]|$1|M|3|N|5|6|7|19|8|@]|9|@]|A|$]]|$1|O|3|P|5|F|7|1A|8|@]|9|@]|A|$G|H]]|$1|Q|3|R|5|6|7|1B|8|@]|9|@$K|1C|L|1D|1|1E]]|A|$]]|$1|S|3|-4|5|6|7|1F|8|@]|9|@]|A|$]]]|T|$U|$5|V|W|X|A|$Y|Z]]|10|$5|V|W|X|A|$Y|11]]]]

There are a few versions of Entity Framework in use.

I myself prefer Code First and with that API it's easy as 

<pre><code>_context.Entry(Entity).Reload();
</code></pre>

Docs
<a href="https://msdn.microsoft.com/en-us/library/system.data.entity.infrastructure.dbentityentry.reload(v=vs.103).aspx" rel="nofollow noreferrer">https://msdn.microsoft.com/en-us/library/system.data.entity.infrastructure.dbentityentry.reload(v=vs.103).aspx</a>

The older API's have a Refresh method on the ObjectContext which can help in certain use cases

<pre><code>ObjectContext.Refresh(RefreshMode.StoreWins, Entity);
</code></pre>

Docs <a href="https://msdn.microsoft.com/en-us/library/bb896255(v=vs.110).aspx" rel="nofollow noreferrer">https://msdn.microsoft.com/en-us/library/bb896255(v=vs.110).aspx</a>

blocks|key|730758|text|这个答案指的是Entity+Framework6。在EF6中有一个原始值和当前值https://msdn.microsoft.com/en-us/library/gg679512(v=vs.113).aspx，在找不到好的答案后，我想出了下面的测试函数，并认为我会把它发布给其他需要这样做的人。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|730759|++++private+void+test()
++++{
++++++++//+table+has+a+field+Description+of+type+varchar(200)
++++++++WDMDBEntities+context+=+new+WDMDBEntities();
++++++++var+query+=+context.Brands;
++++++++List<Brand>+records+=+query.ToList();
++++++++if+(records.Count+>+0)
++++++++{
++++++++++++Brand+currentRecord+=+records[0];
++++++++++++currentRecord.Description+=+"some+new+text";
++++++++++++string+originalValue+=+null;
++++++++++++switch+(context.Entry(currentRecord).State)
++++++++++++{
++++++++++++++++case+System.Data.Entity.EntityState.Added:
++++++++++++++++++++originalValue+=+null;
++++++++++++++++++++break;
++++++++++++++++case+System.Data.Entity.EntityState.Deleted:
++++++++++++++++case+System.Data.Entity.EntityState.Detached:
++++++++++++++++case+System.Data.Entity.EntityState.Modified:
++++++++++++++++case+System.Data.Entity.EntityState.Unchanged:
++++++++++++++++++++originalValue+=+context.Entry(currentRecord).Property(u+=>+u.Description).OriginalValue;
++++++++++++++++++++break;
++++++++++++}
++++++++}
++++++++context.Dispose();
++++}|code-block|syntax|javascript|730760|entityMap|0|LINK|mutability|MUTABLE|url|https://msdn.microsoft.com/en-us/library/gg679512(v=vs.113).aspx^0|14|1S|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@$A|R|B|S|1|T]]|C|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|C|$G|H]]|$1|I|3|-4|5|6|7|V|8|@]|9|@]|C|$]]]|J|$K|$5|L|M|N|C|$O|P]]]]

This answer refers to Entity Framework 6. In EF 6 there is an Original value and Current value <a href="https://msdn.microsoft.com/en-us/library/gg679512(v=vs.113).aspx" rel="nofollow noreferrer">https://msdn.microsoft.com/en-us/library/gg679512(v=vs.113).aspx</a> After looking and not finding a good answer I came up with the following test function and thought I would post it for others needing to do the same. 

<pre><code> private void test()
 {
 // table has a field Description of type varchar(200)
 WDMDBEntities context = new WDMDBEntities();
 var query = context.Brands;
 List&lt;Brand&gt; records = query.ToList();
 if (records.Count &gt; 0)
 {
 Brand currentRecord = records[0];
 currentRecord.Description = "some new text";
 string originalValue = null;
 switch (context.Entry(currentRecord).State)
 {
 case System.Data.Entity.EntityState.Added:
 originalValue = null;
 break;
 case System.Data.Entity.EntityState.Deleted:
 case System.Data.Entity.EntityState.Detached:
 case System.Data.Entity.EntityState.Modified:
 case System.Data.Entity.EntityState.Unchanged:
 originalValue = context.Entry(currentRecord).Property(u =&gt; u.Description).OriginalValue;
 break;
 }
 }
 context.Dispose();
 }
</code></pre>

In EF 4.0, if I understand it right, there are two type of values in Entity : current values and original values. 
We can set original values by calling ApplyOriginalValues(TEntity) method but how to get original values ?

How to get original values of an entity in Entity Framework?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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在EF 4.0中，如果我理解正确的话，Entity中有两种类型的值:当前值和原始值。我们可以通过调用ApplyOriginalValues(TEntity)方法来设置原始值，但是如何获得原始值呢？

问如何在实体框架中获取实体的原始值？
EN

回答 7

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问如何在实体框架中获取实体的原始值？EN

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问如何在实体框架中获取实体的原始值？
EN