Avalonia UI - How to get/set properties of UI controls from code

Question

I have several TabControl s defined in my XAML. I would like my ViewModel to be aware of the TabItem name or the index of the TabItem that is selected.

I also have a ScrollViewer that i would like to always scroll to the bottom when ever a button is pressed.

I should be able to solve both of the above issues if i could somehow get access to the elements in my code.

How can i acheve something like this:

var tabIndex = this.GetElement<TabControl>("NameOfSomeTabControl").SelectedIndex;

var scrollViewer = this.GetElement<ScrollViewer>("NameOfSomeScrollViewer");
scrollViewer.VerticalScrollBarValue = scrollViewer.VerticalScrollBarMaximum;

Edit: code for xaml , viewModel code

Edit 2: Looks like i am able to get the instance of the element from the window class , however i'm still not sure how to pass the reference to the ViewModel.

Edit 3: I can achieve the scroll viewer going to the bottom automatically using the code below. however, once that method is invoked it seems like the scrolling gets disabled.

var tbRaw = this.Get<TextBlock>("tbRawOutput");
tbRaw.PropertyChanged += (s,e) => {
    var svRaw = this.Get<ScrollViewer>("svRawOutput");
    svRaw.Offset = new Vector(svRaw.Offset.X, svRaw.Extent.Height -svRaw.Viewport.Height);};

Answer 1

An easier way to do this might be to use the DataContextChanged event handler in your main Window class:

public MainWindow()
{
    InitializeComponent();
    DataContextChanged += (object sender, EventArgs wat) =>
    {
        // here, this.DataContext will be your MainWindowViewModel
    };
}

Then you can attach more event handlers/use getters and setters on the view model from the Window