How to set different HorizontalAlignment to ListBoxItems

Question

I posted a question yesterday but I think I failed to explain it correctly.

Let me try again.

So this is my goal:

Answer 1

that would be my dirty working example

code-behind

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();

        var l = new List();

        for(int i=0;i<5;i++)
        {
        l.Add(new lItem(true,"aaa"+i));
        l.Add(new lItem(false,"bbb"+i));
        }

        sads.ItemsSource = l;

    }
}


public class lItem
{
    public string Text { get; set; }
    public Brush Color { get; set; }
    public HorizontalAlignment alig { get; set; }

    public lItem(bool ss, string str)
    {
        Text = str;
        Color = Brushes.Blue;
        alig = HorizontalAlignment.Right;

        if (ss)
        {
            Color = Brushes.Red;
            alig = HorizontalAlignment.Left;
        }
    }
}

Xaml

i would recommend to use trigger instead of define visual parts in your ViewModel