Wait until media element has naturalDuration information - vb.net

Question

I need to make a loop to look at a lot of mp3 files and getting their naturalDuration property using a mediaElement. The problem is that mediaElement need some time to load every single file and .source property works like async process (I think) because I have to click two times on below code if I want to obtain naturalDuration property. First click I have just 00:00:00 value, second clik give me real value.
Private Sub button_Click(sender As Object, e As RoutedEventArgs) Handles button.Click
mediaElement.Source = New Uri("\\Mac\Home\Desktop\NOVEDADES01\AbrahamMateo-OldSchool.mp3")
textBlock.Text = mediaElement.NaturalDuration.ToString
End Sub
If I try to wait after .Source instruction, the application keeps on loop.
Private Sub button_Click(sender As Object, e As RoutedEventArgs) Handles button.Click
mediaElement.Source = New Uri("\\Mac\Home\Desktop\NOVEDADES01\AbrahamMateo-OldSchool.mp3")
Do
Loop Until mediaElement.NaturalDuration.TimeSpan.TotalSeconds > 0
textBlock.Text = mediaElement.NaturalDuration.ToString
End Sub
I also have try set .source through an async process and wait for mediaOpenend event, but it look like mediaElemento can not end until the first click was ending
How could I get real value of naturalDuration inside one single process or function just after set .source property and without playing the file?
Thanks a lot!!

Answer 1

Ok, late and may be not so elegant but this was my solution for getting duration of a mp3 file. I used MusicProperties Class.
Public Function infoMP3(elfichero As String) As String
Dim salida As String = ""
Dim miTask = Task.Run(Async Function() As Task(Of String)
Dim musicFile As StorageFile = Await StorageFile.GetFileFromPathAsync(elfichero)
Dim FileProperties As StorageItemContentProperties = musicFile.Properties
Dim musicFileProperties As MusicProperties = Await FileProperties.GetMusicPropertiesAsync()
Dim tiempo = musicFileProperties.Duration
Dim horas As String
If tiempo.Hours < 10 Then
horas = "0" & tiempo.Hours.ToString
Else
horas = tiempo.Hours.ToString
End If
Dim minutos As String
If tiempo.Minutes < 10 Then
minutos = "0" & tiempo.Minutes.ToString
Else
minutos = tiempo.Minutes.ToString
End If
Dim segundos As String
If tiempo.Seconds < 10 Then
segundos = "0" & tiempo.Seconds.ToString
Else
segundos = tiempo.Seconds.ToString
End If
Dim autor = musicFileProperties.Artist
Dim titulo = musicFileProperties.Title
Dim presalida As String = "[" & horas & ":" & minutos & ":" & segundos & "];[" & titulo & "];[" & autor & "] " & elfichero
Return presalida
End Function)
miTask.Wait()
salida = miTask.Result
Return salida
End Function
To get access to the files later on Windows 10, you have to save permission for the files and/or folders. Do this when you select them.
...
Dim listToken = Windows.Storage.AccessCache.StorageApplicationPermissions.FutureAccessList.Add(rutaS)
...
where rutaS is an SotorageFolder object.