實體附加到上下文並且無法刪除它

Question

我在我的實體內部的一個方法中創建一個上下文來檢查某些東西，但我沒有跟蹤任何東西，但是當我嘗試保存在調用代碼上下文中時，它會引發異常。

這是主要的背景下調用代碼，我要保存：

var espToProcess = db.RootDomainEmailSeriesProgresses; 

foreach (var esp in espToProcess) 
{ 
    bool carryOn = esp.MoveNext(); 
    db.SaveChanges(); //Exception 
    if (!carryOn) continue; 

    //--> rest of my code 
} 

這是RootDomainEmailSeriesProgress類中的方法。

public bool MoveNext() 
{ 
    if (this.CompletedTargets == null) this.CompletedTargets = new List<EmailAddress>(); 

    if (this.CurrentTarget != null) 
    { 
     this.CompletedTargets.Add(this.CurrentTarget); 
     this.CurrentTarget = null; 
    } 
    this.CurrentProgress = ""; 

    if (this.RootDomain.ContactFilter != RootDomain.ContactFilterType.None) 
    { 
     this.Status = EmailSeriesStatus.Aborted; 
     return false; 
    } 

    var allTargets = RootDomainEmailManager.SortDomainsEmailsByDesirability(this.RootDomain.ID); 
    var toDo = allTargets.Except(this.CompletedTargets); 
    if (toDo.Count() < 1) 
    { 
     this.Status = EmailSeriesStatus.Completed; 
     return false; 
    } 

    List<string> targetEmailList = allTargets.Select(e => e.Email).ToList(); 
    List<EmailFilter> emailFilters = this.GetFilters(allTargets); 

    if (emailFilters.Any(x => x.Filter == EmailFilterType.Unsubscribe || x.Filter == EmailFilterType.Responded || x.Filter == EmailFilterType.ManualContactOnly)) 
    { 
     this.Status = EmailSeriesStatus.Aborted; 
     if (this.RootDomain.ContactFilter == 0) this.RootDomain.ContactFilter = RootDomain.ContactFilterType.HasAssociatedEmailFilter; 
     return false; 
    } 

    this.CurrentTarget = toDo.First(); 

    return true; 

} 

private List<EmailFilter> GetFilters(List<EmailAddress> allTargets) 
{ 
    using (var db = new PlaceDBContext()) 
    { 
     db.Configuration.AutoDetectChangesEnabled = false; 
     db.Configuration.LazyLoadingEnabled = false; 

     var targetEmailList = allTargets.Select(e => e.Email).ToList(); 
     return db.EmailFilters.AsNoTracking().Where(x => targetEmailList.Contains(x.Email)).ToList(); 

    } 
} 

它拋出該異常：

兩個對象之間的關係不能被限定，因爲它們連接到不同的ObjectContext對象。

我看不出爲什麼esp被連接到另一個上下文。我只是簡單地需要這個背景，我如何將它關閉以免它導致我遇到問題？

Answer 1

，由於有差別的DbContext在foreach循環和GetFilters實例方法

您可以重試此代碼

var espToProcess = db.RootDomainEmailSeriesProgresses; 

foreach (var esp in espToProcess) 
{ 
    bool carryOn = esp.MoveNext(db); 
    db.SaveChanges(); //Exception 
    if (!carryOn) continue; 

    //--> rest of my code 
} 


public bool MoveNext(DbContext db) 
{ 
    if (this.CompletedTargets == null) this.CompletedTargets = new 
List<EmailAddress>(); 

    if (this.CurrentTarget != null) 
    { 
     this.CompletedTargets.Add(this.CurrentTarget); 
     this.CurrentTarget = null; 
    } 
    this.CurrentProgress = ""; 

    if (this.RootDomain.ContactFilter != RootDomain.ContactFilterType.None) 
    { 
     this.Status = EmailSeriesStatus.Aborted; 
     return false; 
    } 

    var allTargets = 
RootDomainEmailManager.SortDomainsEmailsByDesirability(this.RootDomain.ID); 
    var toDo = allTargets.Except(this.CompletedTargets); 
    if (toDo.Count() < 1) 
    { 
     this.Status = EmailSeriesStatus.Completed; 
     return false; 
    } 

    List<string> targetEmailList = allTargets.Select(e => e.Email).ToList(); 
    List<EmailFilter> emailFilters = this.GetFilters(allTargets, db); 

    if (emailFilters.Any(x => x.Filter == EmailFilterType.Unsubscribe || 
x.Filter == EmailFilterType.Responded || x.Filter == 
EmailFilterType.ManualContactOnly)) 
    { 
     this.Status = EmailSeriesStatus.Aborted; 
     if (this.RootDomain.ContactFilter == 0) 
this.RootDomain.ContactFilter = 
RootDomain.ContactFilterType.HasAssociatedEmailFilter; 
     return false; 
    } 

    this.CurrentTarget = toDo.First(); 

    return true; 

} 

private List<EmailFilter> GetFilters(List<EmailAddress> allTargets, DbContext db) 
{ 
    db.Configuration.AutoDetectChangesEnabled = false; 
    db.Configuration.LazyLoadingEnabled = false; 

    var targetEmailList = allTargets.Select(e => e.Email).ToList(); 
    return db.EmailFilters.AsNoTracking().Where(x => 
targetEmailList.Contains(x.Email)).ToList(); 

}