c# - Entity attaching to context and unable to remove it -

i creating context in method inside entity check not tracking when try save in calling code context throws exception.

this calling code in main context want save:

var esptoprocess = db.rootdomainemailseriesprogresses;  foreach (var esp in esptoprocess) {     bool carryon = esp.movenext();     db.savechanges();   //exception     if (!carryon) continue;       //--> rest of code } 

this methods inside rootdomainemailseriesprogress class.

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();      } } 

it throws out exception:

the relationship between 2 objects cannot defined because attached different objectcontext objects.

i can't see why esp gets attached other context. need context briefly, how kill off stops causing me issues?

that because there difference dbcontext instances in foreach loop , getfilters method

you can retry code

var esptoprocess = db.rootdomainemailseriesprogresses;  foreach (var esp in esptoprocess) {     bool carryon = esp.movenext(db);     db.savechanges();   //exception     if (!carryon) continue;       //--> rest of 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(); 

}