C# / VB.NET - Hub controllo vb.net

Postato originariamente da lsdinfo:

Ciao a tutti sono nuovo del forum.
Volevo chiedere qualche consiglio su come risolvere questo mio problema.
Sto realizzando un applicazione universal windows app e sto utilizzando un controllo Hub per poter scorrere orizzontalmente sul cellulare.
Questa Hub ha 2 hubSection all'interno di ognuna i controlli sono raggruppati dentro una <Grid>.

<Page
x:Class="App17.MainPage"
xmlns="schemas.microsoft.com/winfx/2006/xaml/…;
xmlns:x="schemas.microsoft.com/winfx/2006/…;
xmlns:local="using:App17"
xmlns="schemas.microsoft.com/expression/blend/…;
xmlns:mc="schemas.openxmlformats.org/markup-compatibility/…;
mc:Ignorable="d">

<Hub Header="INFUSION RATE" Background="White" FontFamily="verdana" FontSize="40" Margin="0,10,-360,0">
<HubSection Header="Calcolo velocità" FontFamily="verdana" FontSize="32" Height="619" Width="362">
<HubSection.Background>
<ImageBrush Stretch="Fill" ImageSource="Assets/Square150x150Logo.png"/>
</HubSection.Background>
<DataTemplate>

<Grid HorizontalAlignment="Left" Height="397" Margin="10,10,-27,0" VerticalAlignment="Top" Width="340">
<TextBlock x:Name="textBlock" HorizontalAlignment="Left" TextWrapping="Wrap" Text="FARMACO" FontFamily="verdana" FontSize="22" VerticalAlignment="Top" Width="142"/>
<TextBlock x:Name="textBlock1" HorizontalAlignment="Left" TextWrapping="Wrap" Text="Quantità" FontFamily="verdana" FontSize="16" VerticalAlignment="Top" Margin="0,27,0,0"/>
<TextBox x:Name="txtQuantità" HorizontalAlignment="Left" Height="36" Margin="74,27,0,0" TextWrapping="Wrap" Text="" FontFamily="verdana" FontSize="22" VerticalAlignment="Top" Width="47" InputScope="Number"/>
<TextBlock x:Name="textBlock2" HorizontalAlignment="Left" TextWrapping="Wrap" Text="mg in" FontFamily="verdana" FontSize="16" VerticalAlignment="Top" Margin="147,27,0,0" RenderTransformOrigin="2.406,1.211"/>
<TextBox x:Name="txtVolume" HorizontalAlignment="Left" Height="36" Margin="198,27,0,0" TextWrapping="Wrap" Text="" FontFamily="verdana" FontSize="22" VerticalAlignment="Top" Width="47" InputScope="Number"/>
<TextBlock x:Name="textBlock3" HorizontalAlignment="Left" TextWrapping="Wrap" Text="ml" FontFamily="verdana" FontSize="16" VerticalAlignment="Top" Margin="271,30,0,0" RenderTransformOrigin="2.406,1.211"/>
<TextBlock x:Name="textBlock4" HorizontalAlignment="Left" TextWrapping="Wrap" Text="TERAPIA" FontFamily="verdana" FontSize="22" VerticalAlignment="Top" Width="142" RenderTransformOrigin="0.451,3.926" Margin="0,97,0,0"/>
<TextBlock x:Name="textBlock5" HorizontalAlignment="Left" Height="22" Margin="10,129,0,0" TextWrapping="Wrap" Text="Dose" FontFamily="verdana" FontSize="16" VerticalAlignment="Top" Width="59"/>
<TextBox x:Name="txtDose" HorizontalAlignment="Left" Height="36" Margin="54,124,0,0" TextWrapping="Wrap" Text="" FontFamily="verdana" FontSize="22" VerticalAlignment="Top" Width="68" InputScope="Number"/>
<ComboBox x:Name="comboBox" HorizontalAlignment="Left" Height="32" Margin="127,124,0,0" VerticalAlignment="Top" Width="81" FontFamily="verdana" FontSize="16">
<ComboBoxItem Content="mcg"/>
<ComboBoxItem Content="mg"/>
<ComboBoxItem Content="ng"/>
<ComboBoxItem Content="gr"/>
</ComboBox>
<TextBlock x:Name="textBlock6" HorizontalAlignment="Left" Height="32" Margin="213,124,0,0" TextWrapping="Wrap" Text="/Kg/" FontFamily="verdana" FontSize="16" VerticalAlignment="Top" Width="37" RenderTransformOrigin="0.855,0.458"/>
<ComboBox x:Name="comboBox1" HorizontalAlignment="Left" Height="32" Margin="250,123,0,0" VerticalAlignment="Top" Width="80" FontFamily="verdana" FontSize="16">
<ComboBoxItem Content="min"/>
<ComboBoxItem Content="hr"/>
</ComboBox>
<TextBlock x:Name="textBlock7" HorizontalAlignment="Left" Height="33" Margin="12,173,0,0" TextWrapping="Wrap" Text="Peso" FontFamily="verdana" FontSize="18" VerticalAlignment="Top" Width="57"/>
<TextBox x:Name="txtPeso" HorizontalAlignment="Left" Height="36" Margin="74,173,0,0" TextWrapping="Wrap" Text="" FontFamily="verdana" FontSize="22" VerticalAlignment="Top" Width="47" InputScope="Number"/>
<TextBlock x:Name="textBlock8" HorizontalAlignment="Left" Height="43" Margin="12,229,0,0" TextWrapping="Wrap" Text="INFUSION RATE" FontFamily="verdana" FontSize="32" VerticalAlignment="Top" Width="304"/>
<TextBlock x:Name="textBlock9" HorizontalAlignment="Left" Height="28" Margin="95,277,0,0" TextWrapping="Wrap" Text="0" FontFamily="verdana" FontSize="22" TextAlignment="Center" VerticalAlignment="Top" Width="98"/>
<TextBlock x:Name="textBlock10" HorizontalAlignment="Left" Height="41" Margin="211,288,0,0" TextWrapping="Wrap" Text="ml/hr" FontFamily="verdana" FontSize="10" VerticalAlignment="Top" Width="80" RenderTransformOrigin="0.471,1.44"/>
<Button x:Name="button" Content="Calcola" Height="53" Margin="74,334,78,0" VerticalAlignment="Top" HorizontalAlignment="Center" Width="188" />
</Grid>


</DataTemplate>

</HubSection>
<HubSection Header="Calcolo dosaggio" FontFamily="verdana" FontSize="32" Width="754" Height="619">

</HubSection>

</Hub>
</Page>

Al momento di inserire degli eventi non riesco ad "utilizzate" i vari controlli, ad esempio se creo un evento click per il controllo button che deve memorizzare il valore di una textbox in una variabile non mi riconosce il nome della textbox e mi chiede di dichiararla.

Public NotInheritable Class MainPage
Inherits Page

Private Sub button_Click(sender As Object, e As RoutedEventArgs) Handles button.Click
Dim quantità As Integer
quantità = txtQuantità.text

End Sub
End Class

se inserisco gli stessi controlli al di fuori di un Hub non ho problemi ad usare i controlli.

Grazie a tutti