Get selected text with UI Automation

gistfile1.cs

public static string GetText()
{
    try
    {
        var element = AutomationElement.FocusedElement;
        if (element != null)
        {
            object pattern;
            if (element.TryGetCurrentPattern(TextPattern.Pattern, out pattern))
            {
                var tp = (TextPattern)pattern;
                var sb = new StringBuilder();

                foreach (var r in tp.GetSelection())
                {
                    sb.AppendLine(r.GetText(-1));
                }

                return sb.ToString();
            }
        }
    }
    catch (Exception e)
    {
        Console.WriteLine(e);
    }
    return "";
}