Amoeba.Windows.OptionsWindow._fontMessageFontSizeTextBox_TextChanged C# (CSharp) Method

        private void _fontMessageFontSizeTextBox_TextChanged(object sender, TextChangedEventArgs e)
        {
            if (string.IsNullOrWhiteSpace(_fontMessageFontSizeTextBox.Text)) return;

            var builder = new StringBuilder("");

            foreach (var item in _fontMessageFontSizeTextBox.Text)
            {
                if (Regex.IsMatch(item.ToString(), "[0-9\\.]"))
                {
                    builder.Append(item.ToString());
                }
            }

            var value = builder.ToString();
            _fontMessageFontSizeTextBox.Text = value;
        }