Binding added data to data source

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Greg posted over 16 years ago

I have a situation where I want to add data to a data source in chunks. Because retrieving large amounts of data will be slow, part of the data will be retrieved and bound to the grid as needed. What is the best way to rebind / update the grid when rows are added? Does any data source type behave better with the datagrid than others when the data source size is increased? (It will never shrink).

Thanks.
Greg

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Offline Joe Modica posted over 16 years ago in reply to patrick
Hi -

This should work. A couple of questions:

Can you post the code that updates the binding list?

When you are updating the BindingList, what kind of updates are not being reflected in the UI? adding/removing records? Updating existing records?

What version of the controls are you using?

Joe
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patrick posted over 16 years ago in reply to Joe Modica

Hi,
I'm suffering a similar problem, I have a BindingList<Support> (Support is a Class I made) is a Class, I add this as the DataSource like this :
theDataGrid.DataSource = OneClass.List; //List is a property of OneClass and the list inside is created only once and modified later
When I update the bindingList from the DataBase or by adding element from UI some elements in my list are not visible (most of the time the elements that have just been modified)
Is there something to do to fix the problem??
Thanks
gle
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Offline Joe Modica posted over 16 years ago in reply to Greg

Hi Greg -

Yes to ObservableCollection.

Joe
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Greg posted over 16 years ago in reply to Joe Modica

Thanks, Joe. This is good info, particularly on the background threading.
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Offline Joe Modica posted over 16 years ago

Hi Greg -

As long as the data source fires list changed notifications I don't think one data source type is any better than another. For example, if you use a data source that implements IBindingList and fires the ListChanged event, that should work just fine.

What you will probably want to do when adding data to the data source is to add the records as a group so only a single change notification will be fired for the grid.

BTW - what is the trigger that causes you to load a new batch of records? If you are trying to add new records to your data source on a background thread, please be aware that this is not supported. You would need to add the new records on the UI thread.

Also, since the xamDataGrid only asks the data source for records as it needs them (e.g., when the user scrolls to the next page), you might want to consider using the NetAdvantage WindowsForms control called UltraDataSource which supports virtual data loading via a callback mechanism. In this scenario, when the XamDataGrid asks the UltraDataSource for more records, the callback is called and you can supply the requested records from your back end.

Keep in mind that in all these 'virtual' data loading scenarios, if the user causes the data to be sorted or grouped via the grid's UI, then ALL the records will have to be loaded. You may want to disable sorting and grouping via the UI if this is an issue for your application.

Joe
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