VB code to accessing a textblock from a XAML file?

[Smurfsdabomb]

I have this in my XAML file

 <TextBlock Width="97" Height="28" Canvas.Left="261" Canvas.Top="204" Text="TextBlock" TextWrapping="Wrap" x:Name="textblock1"/>

How would I access that textblock in VB? As in to change its text for example.