Friday, April 9, 2010

Getting ListBoxItem from selected entity

There will be some scenarios where we need to get the object of ListBoxItem which is hosting one of the the bound entity.Most probably it may be the SelectedItem.

Consider this scenario there is an business class called Employee and it’s collection class is EmployeeCollection.We have binding which binds object of EmployeeCollection to a ListBox.If we access the SelectedItem property of ListBox it will return the Employee object.But the requirement is to get the ListBoxItem which hosts the selected entity on an event say SelectionChanged.

Dim lbi As ListBoxItem = lstBox.ItemContainerGenerator.ContainerFromItem(lstBox.SelectedItem)

The above code can be used to get ListBoxItem of any object which is present in the collection.

Wednesday, April 7, 2010

Why WPF ProgressBar is not updating

When you put a loop and try to update the ProgressBar from that loop, it will not update the visual.The visual will update only after the execution of the you can’t see the incremental animation.Here is the solution for that issue.

Private Sub btn_Click(ByVal sender As System.Object, ByVal e As System.Windows.RoutedEventArgs)
End Sub
Sub IncrementContinuously()
For i = 0 To 50
prgs.Dispatcher.Invoke(New CrossAppDomainDelegate(AddressOf IncrementBy1), DispatcherPriority.Background, Nothing)
End Sub
Sub IncrementBy1()
prgs.Value = prgs.Value + 1
End Sub

This link contains some more solutions.