c# – ObjectStateManager不包含ObjectStateEntry,它引用了类型

发布时间：2020-12-16 01:44:50 所属栏目：百科来源：网络整理

导读：我正在使用EISK(员工信息入门套件)来开发应用程序.我的实体图看起来像这样我尝试通过此代码更新应用程序表. int apId = Convert.ToInt32(Request.QueryString["ApplicationID"]); ApplicationBLL objGetApplication = new ApplicationBLL(); Appdec.YEP.Busi

我正在使用EISK(员工信息入门套件)来开发应用程序.我的实体图看起来像这样我尝试通过此代码更新应用程序表.

int apId = Convert.ToInt32(Request.QueryString["ApplicationID"]);

            ApplicationBLL objGetApplication = new ApplicationBLL();

            Appdec.YEP.BusinessEntities.Application objApplication =
            objGetApplication.GetApplicationByApplicationID(apId);



            objApplication.Status = (ddlStatus.SelectedValue == "0" ? false : true);



            new ApplicationBLL(new Appdec.YEP.DataAccessLayer.DatabaseContext()).UpdateApplication(objApplication);

现在商务逻辑的更新方法是

[System.ComponentModel.DataObjectMethodAttribute(System.ComponentModel.DataObjectMethodType.Update,true)]
    public void UpdateApplication(Application updatedApplication)
    {
        // Validate Parameters
        if (updatedApplication == null)
            throw (new ArgumentNullException("updatedApplication"));

        // Validate Primary key value
        if (updatedApplication.ApplicationID.IsInvalidKey())
            BusinessLayerHelper.ThrowErrorForInvalidDataKey("ApplicationID");

        // Apply business rules
        OnApplicationSaving(updatedApplication);
        OnApplicationUpdating(updatedApplication);

        //attaching and making ready for parsistance
        if (updatedApplication.EntityState == EntityState.Detached)
            _DatabaseContext.Applications.Attach(updatedApplication);



_DatabaseContext.ObjectStateManager.ChangeObjectState(updatedApplication,System.Data.EntityState.Modified);//this line throws the error 
//ObjectStateManager does not contain an ObjectStateEntry with a reference to an object of type
        int numberOfAffectedRows = _DatabaseContext.SaveChanges();
        if (numberOfAffectedRows == 0) 
            throw new DataNotUpdatedException("No application updated!");

        //Apply business workflow
        OnApplicationUpdated(updatedApplication);
        OnApplicationSaved(updatedApplication);

    }

有人可以告诉我如何修复此错误并更新表.
当我尝试更新其他表时,同样的错误发生.插件工作正常.
希望不要打扰你.最好的祝福.

解决方法

所以它已经属于一个上下文,你应该更新该上下文.
它不能附加到新的背景,
您可以创建updatedApplication的新实例,并将updatedApplication的所有属性复制到此新实例,并将新实体附加到应用程序.

也改变

if (newApp .EntityState == EntityState.Detached)
            _DatabaseContext.Applications.Attach(newApp );

至

var newApp = Application ();
 //Copy all propery of updatedApplication to  newApp here 

            if (newApp .EntityKey == null || newApp .EntityKey.IsTemporary)
            {
                _DatabaseContext.Applications.AddObject(newApp );
            }
            else
            {
                _DatabaseContext.Applications.Attach(newApp );
            }
_DatabaseContext.ObjectStateManager.ChangeObjectState(newApp,System.Data.EntityState.Modified);

（编辑：李大同）

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