ModernWPF.Controls.DialogControl.TryFocus C# (CSharp) Method

        internal void TryFocus()
        {
            // if subclass doesn't override OnFocus then try to find a focusable control ourselves.
            var focusMethod = this.GetType().GetMethod("OnFocus", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);
            if (focusMethod != null && focusMethod.DeclaringType != typeof(DialogControl))
            {
                OnFocus();
            }
            else
            {
                this.ProcessInVisualTree<FrameworkElement>(fe =>
                {
                    var matches = fe.Visibility == System.Windows.Visibility.Visible && fe.IsEnabled && fe.Focusable;
                    if (matches)
                    {
                        fe.Focus();
                    }
                    return matches;
                });
            }
        }