[英]An object with the same key already exists in the ObjectStateManager. when using AsNoTracking
There are many errors here in SO, but this scenario I think its different. SO中有很多错误,但我认为这种情况有所不同。
I had some code that was working fine, I update one entity, etc. But the problem is that it was being cached, when I disabled caching with AsNoTracking(), then it started to throw this exception; 我有一些工作正常的代码,我更新一个实体,等等。但问题是它被缓存,当我使用AsNoTracking()禁用缓存时,它开始抛出此异常;
What I do its the following: 1. In the page I get a EcoBonusRequest. 我做了以下几点:1。在页面中,我获得了EcoBonusRequest。 2. The user clicks a button and it modifies the currentstatus proeprty, and it addsa a list item to a collection of workflowhistories, (an associated collection of the ecobonusrequestobject). 2.用户单击一个按钮,它会修改currentstatus proeprty,并将一个列表项添加到工作流历史的集合中(ecobonusrequestobject的相关集合)。 3. I call the udpate method, setting state to modified, here it throwed the exception. 3.我调用udpate方法,将状态设置为modified,这里抛出了异常。
Here is my code> 这是我的代码>
EcoBonusRequestRepository.cs EcoBonusRequestRepository.cs
public void UpdateEcoBonusRequest(EcoBonusRequest ecoBonusRequest)
{
_context.EcoBonusRequests.Attach(ecoBonusRequest);
_context.Entry(ecoBonusRequest).State = EntityState.Modified;
}
EcoBonusRequestBL EcoBonusRequestBL
public void Update(EcoBonusRequest ecoBonusRequest)
{
DALFacade.UpdateEcoBonusRequest(ecoBonusRequest);
}
EcoBonusRequest Page EcoBonusRequest
public void ChangeStatus(EcoBonusRequest ecoBonusRequest, string stepname, string who, string choosenoption)
{
ecoBonusRequest.WorkflowHistories = new List<WorkflowHistory>
{
new WorkflowHistory()
{
Date = DateTime.Now,
What = choosenoption,
StepName = stepname,
Who = who
}
};
ecoBonusRequest.CurrentStatus = _currentStepBlo.StepName;
var ecoBonusRequestBL = new EcoBonusRequestBL();
ecoBonusRequestBL.Update(ecoBonusRequest);
}
This is how I get the object first: (I am not going to paste all code from all layers here) 这是我首先获得对象的方式:(我不会在这里粘贴所有图层的所有代码)
protected override void OnInit(EventArgs e)
{
var requestBaseId = RequestBaseId;
if (requestBaseId != null)
{
EcoBonusRequest request = GetDBRequest(requestBaseId.Value);
In the dal 在达尔
public IQueryable<EcoBonusRequest> FindEcoBonusRequests(System.Linq.Expressions.Expression<Func<EcoBonusRequest, bool>> predicate)
{
return _context.EcoBonusRequests.AsNoTracking().Where(predicate);
}
Yeah this is a fun one, the issue here comes from trying to re-attach an entity which is already attached to the context. 是的,这是一个有趣的问题,这里的问题来自于试图重新附加已经附加到上下文的实体。 This can come from a logic error or perhaps you are reusing your context without clearing the attached objects. 这可能来自逻辑错误,或者您可能在不清除附加对象的情况下重用上下文。 There is a local collection on the database which you can use to see what items are currently attached to the context. 数据库上有一个本地集合,您可以使用它来查看当前附加到上下文的项目。
ctx.YourEntityCollection.Local
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