Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
457 views
in Technique[技术] by (71.8m points)

c# - EntityFramework show entities before saving changes

Entity Framework ObjectSet with its method ToList shows just saved entities. That means, when I call

context.AddToCustomers(myNewCust);

and then (without calling SaveChanges)

myDataGrid.DataContext = context.Customers.ToList();

the DataGrid doesn't show the newly added entity (even context.Customers.Count() doesn't include it).

Is there any way to show these entities (those with EntityState = Added) ?

Thanks in advance.

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

I think you can get unsaved added entities by calling something like:

var inserted = context.ObjectStateManager
                      .GetObjectStateEntries(EntityState.Added)
                      .Where(e => !e.IsRelationship)
                      .Select(e => e.Entity)
                      .OfType<Cutomer>();

But just by reading your question, I'm affraid that you are trying to do something wrong. Why do you need to combine unsaved entities with retrieved? If you need to show unsaved content you should simply keep it in your own separate collection.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...