How to navigate to other page with button in WPF

Solution to my own question:

I feel a bit silly providing a solution to my own question but thanks to Jasti's link I was able to sort my code out. As he had only posted a comment, I can't mark it as an answer, so here is the solution.

I changed the NavigationWindow to a Window and inserted:

<DockPanel>
    <Frame x:Name="_NavigationFrame" NavigationUIVisibility="Hidden" />
</DockPanel>

And within the constructor of the MainWindow.xaml.cs I added:

_NavigationFrame.Navigate(new Page1());

Then the last step was to adjust the button event handler to:

this.NavigationService.Navigate(new Uri("Pages/Page2.xaml", UriKind.Relative));

You should use this, this worked for me:

var Page2= new Page2(); //create your new form.
Page2.Show(); //show the new form.
this.Close(); //only if you want to close the current form.

There is a variable type of a page with the page.xaml right name in your solution. after that, you should use its methods to do it functionally.