Dispatcher.Invoke

Dim folderName As String = Dispatcher.Invoke(DispatcherPriority.Normal, New Func(Of String)(Function() txtFolderName.Text))

Dispatcher.Invoke(DispatcherPriority.Normal, New Action(Sub() lblProgress.Content = i & " / " & BackupPhotos.Count))

Remove pdb files when compile

There is an option in the “Project Properties", “Build", “Advanced…".

Change “Debug Info:" to None.