有没有一种方法可以将FormattedText包含在带有Xamarin.Forms的.alert中？

using Xamarin.Forms;
using Xamarin.Forms.Platform.iOS;

[assembly: ExportRenderer(typeof(Alert), typeof(CustomAlertRenderer))]
namespace YourNamespace.iOS
{
    public class CustomAlertRenderer : PageRenderer
    {
        protected override void OnElementChanged(VisualElementChangedEventArgs e)
        {
            base.OnElementChanged(e);

            if (e.NewElement is Alert alert)
            {
                var alertController = UIAlertController.Create(alert.Title, alert.Message, UIAlertControllerStyle.Alert);

                // 创建一个NSMutableAttributedString来包含FormattedText的样式
                var attributedString = new NSMutableAttributedString(alert.Message);

                // 设置FormattedText的样式
                var formattedText = alert.FormattedMessage;
                var range = new NSRange(0, formattedText.Spans[0].Text.Length);
                var attributes = new UIStringAttributes
                {
                    Font = UIFont.BoldSystemFontOfSize(16),
                    ForegroundColor = UIColor.Red
                };
                attributedString.SetAttributes(attributes, range);

                // 将NSMutableAttributedString设置为UIAlertController的message
                alertController.SetValueForKey(attributedString, new NSString("attributedMessage"));

                // 添加按钮
                alertController.AddAction(UIAlertAction.Create("OK", UIAlertActionStyle.Default, null));

                // 显示alert
                PresentViewController(alertController, true, null);
            }
        }
    }
}

using Xamarin.Forms;

namespace YourNamespace
{
    public class Alert
    {
        public string Title { get; set; }
        public string Message { get; set; }
        public FormattedString FormattedMessage { get; set; }

        public void Show()
        {
            // 在这里调用自定义渲染器来显示.alert
            MessagingCenter.Send(this, "ShowAlert");
        }
    }
}

var alert = new Alert
{
    Title = "Alert",
    Message = "This is a formatted text alert.",
    FormattedMessage = new FormattedString
    {
        Spans =
        {
            new Span { Text = "This is ", FontAttributes = FontAttributes.Bold },
            new Span { Text = "formatted text", ForegroundColor = Color.Red, FontAttributes = FontAttributes.Bold },
            new Span { Text = " in an alert." }
        }
    }
};

alert.Show();