How to access the main window from another class in WPF?

Question

WPF

I am writing a desktop app.
There is a MainWindow.xaml.cs class. This is the main window of the application
. I have a code that, on pressing a hot key, the window is toggled to fullscreen.
I don't want to write a lot of code in one MainWindow.xaml.cs file. I
need to break the code into classes
. How can I get window parameters in another class so that they can be manipulated?
For example, create a class HotKeys.cs and write code there that will be responsible only for the hot keys of the window
Code for the hot key:

this.ResizeMode = ResizeMode.NoResize;
 this.WindowStyle = WindowStyle.None;
 this.WindowState = WindowState.Maximized;
            
  this.PreviewKeyDown +=
   (s, e) =>
 {                    

                    if (((Keyboard.Modifiers & ModifierKeys.Alt) == ModifierKeys.Alt) && Keyboard.IsKeyDown(Key.Enter))
                        
                    {
                       
                        if (this.WindowStyle != WindowStyle.SingleBorderWindow)
                        {
                            this.ResizeMode = ResizeMode.CanResize;
                            this.WindowStyle = WindowStyle.SingleBorderWindow;
                            this.WindowState = WindowState.Normal;                           
                            e.Handled = true;                            
                        }
                        else
                        {
                            this.ResizeMode = ResizeMode.NoResize;
                            this.WindowStyle = WindowStyle.None;
                            this.WindowState = WindowState.Maximized;
                            e.Handled = true;
                        }
                    }
                };

MainWindow.xaml.cs:

namespace Toolkits
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
       
        public MainWindow()
        {
            InitializeComponent();
           
        }
    }
}

Answer 1

Passing this to the constructor of the new class.

class HotKeys
{
     private MainWindow window;
     //Конструктор
     public HotKeys(MainWIndow _window)
     {
          window = _window;
     }
}

namespace Toolkits
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
       
        public MainWindow()
        {
            InitializeComponent();
            HotKeys hk = new HotKeys(this);           
        }
    }
}

Answer 2

Application.Current.MainWindow