Better-Seewo/Manager/MainWindow.xaml.cs

using System.Windows;
using System.Windows.Controls;

namespace BetterSeewoManager;

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
        ContentFrame.Navigate(new System.Uri("Pages/InstallPage.xaml", System.UriKind.Relative));
    }

    private void Tab_Click(object sender, RoutedEventArgs e)
    {
        if (sender is RadioButton rb && rb.Tag is string pageName)
        {
            var pageUri = new System.Uri($"Pages/{pageName}.xaml", System.UriKind.Relative);
            ContentFrame.Navigate(pageUri);
        }
    }
}