我有一个允许用户将记录标记为已删除的 MVVM 应用程序
public void DeleteRecord(object p)
{
db.entry((MyEntityCast)p).state = EntityState.Deleted;
((DelegateCommand)ICommandSave).RaiseCanExecuteChanged();
}
然后我ICommandSave
用这个canExecute保存:
public bool canExecuteSave(object param)
{
decimal count = (from c in MyList
select c).Count(x=> db.Entry(x).State != EntityState.Unchanged);
return count !=0;
}
我的问题是 count 总是返回ListaTipoAsociado
较少的已删除项目,这意味着
如果MyList.count = 5
,并且用户标记删除 2 个项目,则此查询返回0
,并将MyList.count
新值设置为3
。
我的问题是?
为什么如果记录仅marked
用于删除(尚未删除),我无法在查询中访问它们?
我缺少一个EF设置吗?
更新 2: MyList 定义
private ObservableCollection<MyEntity> _MyList;
public ObservableCollection<MyEntity> MyList
{
get { return _MyList; }
set { SetProperty(ref _MyList, value); }
}
public constructor()
{
var Q= from ta in db.MyEntity
select ta;
MyList= new ObservableCollection<MyEntity>(Q.ToList());
}
更新 3:类定义
public partial class MyEntity
{
public MyEntity()
{
this.Childs = new HashSet<MyEntity2>();
}
public int IntTipoAsociado { get; set; }
public string StrDescripcionTipoAsociado { get; set; }
public virtual ICollection<MyEntity2> MyEntity2{ get; set; }
}
和上下文:
public partial class MyEntities : DbContext
{
public MyEntities()
: base("name=MyEntities")
{
}
public MyEntities(string connectioString)
: base(connectioString)
{
}
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
throw new UnintentionalCodeFirstException();
}
public DbSet<MyEntity> MyEntity { get; set; }
public DbSet<MyEntity2> MyEntity { get; set; }
}