EF framework LIKE Hibernate SaveOrUpdate()

 from：
http://stackoverflow.com/questions/7552433/what-is-the-equivalent-for-hibenate-saveorupdate-in-entity-framework
果然是stackflow，馬上找到

There is no equivalent. You really have to write it like:

using (DataContext context = new DataContext())
{
    context.Task.Attach(task);
    if (task.ID == 0)
    {
         context.ObjectStateManager.ChangeObjectState(task, System.Data.EntityState.Added);
    }
    else
    {
         context.ObjectStateManager.ChangeObjectState(task, System.Data.EntityState.Modified);
    }

    context.SaveChanges();
 }