VB.NET How to "Refresh" data DbContext in winform - vb.net

Question

I have a DataDridview filled with objects queried with my DbContext.
I show some basic informations about my objects in this form.
I would like to query the most recent infos from the BD every time I select a different object in the DataDridview. I also want to be able to modify these objects.
I'm already able to do that. To modify an object, for example, I will do these steps:
-create a new DbContext
-get the object from my Datagridview using .Selectedrows(0).DatabountItem
-with that object's id I will query the (most recent) record in the DB using my new DbContext
-assign the old object (modified) properties to the new ones, one by one
-.SaveChanges on my new Dbcontext.
But there has to a better way, right? :/
If I understand correctly, by doing it this way I end up with a ton of unused Dbcontext and I doubt it's best practices.
But whenever I .Dispose my context, all EF navigation properties are broken and I get exceptions popping all over the place... So the ideal solution seems to me to just, refresh the data in a unique DbContext that I would use for the entire form. But is it even possible?
Maybe the solutions is obvious but I just can't see it.
If I'm unclear, please let me know I'll do my best to reformulate.
Any help would be appreciated, thanks!
** Edit **
In the end, here's the solution that worked best for me:
I do create a new DbContext for every logical operation, then immediatly .Dispose it...
Except for when I show informations about a specific row in my datagridview.
Instead, I create a new Context and leave it open. I will .Dispose only when the datagridview.SelectionChanged event fires.
The reason for not Disposing this context immediatly is: If a user saves his changes, but in the meantime someone else also saved changes on the same record, the (not-synced) context will hit a concurrency issue.. and I can let the user know about it, instead of overriding that row, which would be bad.
If I need these navigations properties from EF elsewhere, I can simply do eager loding by .Include("MyOtherTable") everything I need.( because navigation properties stop working when a context is Disposed)

Answer 1

I would use only one context in this case. You must just pay attention for accesing context from another threads - it can result in transaction errors ("New transaction is not allowed because there are other threads running in the session")
If you use DataGridView with DataSource from EF Context, all you have to do is just reload entities.
I wrote extension method in my context:
public partial class MyContext : testEntities1
{
public void Refresh(IEnumerable entities)
{
var ctx = ((IObjectContextAdapter)this).ObjectContext;
ctx.Refresh(System.Data.Entity.Core.Objects.RefreshMode.StoreWins, entities);
}
}
it is much faster than entry.Reload();
F.E.:
List<MyEntities> items = new List<MyEntities>();
foreach(DataGridViewRow row in dataGridView1.SelectedRows)
{
items.Add((MyEntities)row.DataBoundItem);
}
context.Refresh(items);