WPF render string as Image via DrawingVisual DrawingContext FormattedText RenderTargetBitmap

//xaml
<Window x:Class="WpfApp150.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfApp150"
        mc:Ignorable="d"
        WindowState="Maximized"
        Title="MainWindow" Height="450" Width="800">
    <Grid>
        <Image x:Name="img" 
               HorizontalAlignment="Left" 
               VerticalAlignment="Top"/>
    </Grid>
</Window>



//cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Globalization;


namespace WpfApp150
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        int idx = 0;
        private string fontFamilyName = "Arial";
        private int fontSize = 120;
        string guidStr = "";

        public MainWindow()
        {
            InitializeComponent();
            this.Loaded += MainWindow_Loaded;
        }

        private void MainWindow_Loaded(object sender, RoutedEventArgs e)
        {
            GenerateTextAsImageSource();
            System.Timers.Timer tmr = new System.Timers.Timer();
            tmr.Elapsed += Tmr_Elapsed;
            tmr.Interval = 1000;
            tmr.Start();             
        }

        private void Tmr_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
        {
            Application.Current?.Dispatcher.BeginInvoke(new Action(() => 
            {
                GenerateTextAsImageSource();
            }));
        }

        private void GenerateTextAsImageSource()
        {
            // The text to be rendered
            guidStr = Guid.NewGuid().ToString("N");
            this.Title = guidStr;
            string txtStr = $"{++idx}\n\n{DateTime.Now.ToString("yyyyMMddHHmmssffff")}\n\n" +
                $"{WrapTextStr(guidStr, (int)this.ActualWidth - 50, fontFamilyName, fontSize)}";

            // Create a DrawingVisual
            DrawingVisual drawingVisual = new DrawingVisual();

            // Open a DrawingContext to draw on the DrawingVisual
            using (DrawingContext drawingContext = drawingVisual.RenderOpen())
            {
                // Create a FormattedText object to format the text
                FormattedText formattedText = new FormattedText(
                    txtStr,
                    CultureInfo.CurrentCulture,
                    FlowDirection.LeftToRight,
                    new Typeface(fontFamilyName),
                    120,
                    Brushes.Red,
                    1.25
                );

                // Draw the formatted text on the DrawingContext
                drawingContext.DrawText(formattedText, new Point(0, 0));
            }

            // Convert the DrawingVisual to an ImageSource
            ImageSource imageSource = ConvertDrawingVisualToImageSource(drawingVisual);

            // Set the ImageSource to the Image control
            img.Source = imageSource;
            this.Title = guidStr;
            Application.Current?.Dispatcher.BeginInvoke(new Action(() =>
            {
               
            }));
        }

        string WrapTextStr(string text, int maxWidth, string fontFamilyName, int fontSize)
        {
            char[] words = text.ToCharArray();
            StringBuilder builder = new StringBuilder();
            string lineStr = "";
            foreach (char word in words)
            {
                if (GetTextFontsizeWidth(lineStr, fontFamilyName, fontSize) > maxWidth)
                {
                    builder.AppendLine(lineStr);
                    lineStr = "";
                }
                lineStr += word;
            }
            builder.AppendLine(lineStr);
            return builder.ToString();
        }

        private int GetTextFontsizeWidth(string str, string fontFamilyName, int fontSize)
        {
           FormattedText formattedText = new FormattedText(
           str,
           System.Globalization.CultureInfo.CurrentCulture,
           FlowDirection.LeftToRight,
           new Typeface(fontFamilyName),
           fontSize,
           Brushes.Black, 1.25);
           int width = (int)formattedText.Width;
           return width;
        }

        private ImageSource ConvertDrawingVisualToImageSource(DrawingVisual visual)
        {
            if (visual == null)
            {
                return null;
            }

            // Create a RenderTargetBitmap with the desired size
            RenderTargetBitmap rtb = new RenderTargetBitmap(
               (int)this.ActualWidth,
               (int)this.ActualHeight,
                96, // DPI X
                96, // DPI Y
                PixelFormats.Default
            );

            // Render the DrawingVisual onto the RenderTargetBitmap
            rtb.Render(visual);

            return rtb;
        }
    }
}