Question

我真的希望有人可以帮助我。我有以下控制器动作：

public ActionResult Edit(EditViewModel vm)
    {
        Item item= db.Items.Find(vm.ItemId);
        if (ModelState.IsValid)
        {
            //breakpoint 1 --> everything works fine, if its debugged step by step from here

            //if item´s contact is null or different from viewmodel --> override it
            if (item.Contact == null || item.Contact.ContactId != vm.ContactId)
                item.Contact = db.Contacts.Find(vm.ContactId);

            //if the viewmodel have a ContractUnit set and its different from item´s --> override the contractunit
            //is the ContractUnit in viewmodel null set item´s null too
            if (vm.ContractUnitId.HasValue && ((item.ContractUnit != null && item.ContractUnit.ContractUnitId != vm.ContractUnitId) || item.ContractUnit == null))
                item.ContractUnit = db.ContractUnits.Find(vm.ContractUnitId);
            else 
                if (!vm.ContractUnitId.HasValue)
                    item.ContractUnit = null;

            //same as above just for Building
            if (vm.BuildingId.HasValue && ((item.Building != null && item.Building.BuildingId != vm.BuildingId) || item.Building == null))
                item.Building = db.Buildings.Find(vm.BuildingId);
            else 
                if (!vm.BuildingId.HasValue)
                    item.Building = null;

            //same as above just for EconomicUnit
            if (vm.EconomicUnitId.HasValue && ((item.EconomicUnit != null && item.EconomicUnit.EconomicUnitId != vm.EconomicUnitId) || item.EconomicUnit == null))
                item.EconomicUnit = db.EconomicUnits.Find(vm.EconomicUnitId);
            else 
                if (!vm.EconomicUnitId.HasValue)
                    item.EconomicUnit = null;

            //breakpoint 2 --> (no changes to item, if its the first breakpoint)
            item= vm.GetItem(item); //override non relational data
            db.Entry(item).State = EntityState.Modified;
            db.SaveChanges();
            return RedirectToAction("Index");
        }
...
  }

来自EditViewModel的方法GetItem：

    public Item GetItem(Item item)
    {
        item.DateReported = this.DateReported; //Datetime
        item.Description = this.Description; //String
        item.FirstDeadline = this.FirstDeadline; //Datetime
        item.SecondDeadline = this.SecondDeadline; //Datetime
        item.ThirdDeadline = this.ThirdDeadline; //Datetime
        item.ReplacementDeadline = this.ReplacementDeadline; //Datetime
        return item;
    }

问题：EF没有将更改保存到item.Building，item.ContractUnit或item.EconomicUnit。但它确实在我一步一步地调试它。抛出没有错误或异常，并且正确填充了viewmodel和model。

我真的希望有人能帮我解决这个问题......

Answer 1

我从项目模型中移除了关系，现在只将ids保存在＆＃34; long？＆＃34;属性。那么，它现在需要额外的工作来获取相关数据，但至少它可以工作。

Answer 2

尝试拨打

DBSet.Attach(entityToUpdate);

之前

db.Entry(item).State = EntityState.Modified;

也许这有帮助。

EF不保存更改

2 个答案: