Font re wpf RichTextBox

Hi Peter,

I wrote solution for you, please take refrence from my code. hope this will work for you.

using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Media;

namespace RichTextBoxFontExample
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            CreateAndSetRichTextBox();
        }

        private void CreateAndSetRichTextBox()
        {
            // Create a new RichTextBox
            RichTextBox richTextBox = new RichTextBox();
            
            // Set default font properties
            richTextBox.FontFamily = new FontFamily("Arial");
            richTextBox.FontSize = 14;
            richTextBox.FontWeight = FontWeights.Normal;
            richTextBox.FontStyle = FontStyles.Normal;

            // Optional: Set initial text with the default font
            richTextBox.Document.Blocks.Clear();
            Paragraph paragraph = new Paragraph();
            paragraph.Inlines.Add(new Run("This is the default text with the default font settings."));
            richTextBox.Document.Blocks.Add(paragraph);

            // Add the RichTextBox to a container, e.g., a Grid
            MainGrid.Children.Add(richTextBox);
        }
    }
}