Xamarin iOS Rich推送通知问题

Question

我正在尝试在ios中实现媒体/丰富/增强通知。我有一个iPhone 6,6s和7.我在有效载荷中发送的图像显示在6上的丰富通知中，但不在6s或7 上。代码似乎只停留在CreateDownloadTask（我已经验证我可以在该行代码之前更改Body文本，但我不能在之后）。我甚至有更简单的版本使用NSData.FromUrl（url），但代码在该行“中断”。奇怪的是，它并没有真正破坏，它显示了最初推送的Body元素的文本。即使是try catch也没有抓住错误。 FYI..category是我正在建造的自定义ui。 无法弄清楚为什么它只能在iphone 6上正常工作（所有手机都在10.2.x或以上）

有效载荷是{＆＃34; aps＆＃34;：{＆＃34; alert＆＃34;：{＆＃34; title＆＃34;：＆＃34; title＆＃34;，＆＃34; subtitle＆ ＃34;：＆＃34;副标题＆＃34;，＆＃34; body＆＃34;：＆＃34; body＆＃34;}，＆＃34; category＆＃34;：＆＃34; pushWithImage＆＃34;， ＆＃34;可变内容＆＃34;：1}，＆＃34; pushImage＆＃34;：＆＃34; https://ewcweb.azurewebsites.net/media/boldlythumb.png＆＃34;}

我无法发送项目，但下面是服务扩展代码：

using System;
using System.Net;
using System.Net.Http;
using System.Threading.Tasks;
using Foundation;
using SDWebImage;
using UIKit;
using UserNotifications;

namespace notifications
{
[Register ("NotificationService")]
public class NotificationService : UNNotificationServiceExtension
{
UNMutableNotificationContent BestAttemptContent { get; set; }
public Action ContentHandler { get; set; }
const string ATTACHMENT_IMAGE_KEY = "pushImage";
const string ATTACHMENT_FILE_NAME = "-attachment-image.";
protected NotificationService (IntPtr handle) : base (handle)
{
// Note: this .ctor should not contain any initialization logic.
}

    public async Task<byte[]> LoadImage (string imageUrl)
    {
        var httpClient = new HttpClient ();
        var contentsTask = await httpClient.GetByteArrayAsync (imageUrl);

        return contentsTask;
    }

    public override void DidReceiveNotificationRequest (UNNotificationRequest request, Action<UNNotificationContent> contentHandler)
    {
        string imageURL = null;

        ContentHandler = contentHandler;
        BestAttemptContent = request.Content.MutableCopy () as UNMutableNotificationContent;

        if (BestAttemptContent != null) {
            if (BestAttemptContent.UserInfo.ContainsKey (new NSString (ATTACHMENT_IMAGE_KEY))) {
                imageURL = BestAttemptContent.UserInfo.ValueForKey (new NSString (ATTACHMENT_IMAGE_KEY)).ToString ();
            }

            if (imageURL == null) {
                ContentHandler (BestAttemptContent);
                return;
            }

            var url = new NSUrl (imageURL.ToString ());

            NSError err = null;

            var task = NSUrlSession.SharedSession.CreateDownloadTask ( new NSMutableUrlRequest (url),(tempfile, response, error) => {

                if (error != null)
                {
                    ContentHandler (BestAttemptContent);
                    return;
                }
                if (tempfile == null)
                {
                    ContentHandler (BestAttemptContent);
                    return;
                }

                var cache = NSSearchPath.GetDirectories (NSSearchPathDirectory.CachesDirectory, NSSearchPathDomain.User, true);
                var cachesFolder = cache [0];
                var guid = NSProcessInfo.ProcessInfo.GloballyUniqueString;
                var fileName = guid + ".png";
                var cacheFile = cachesFolder + "/" + fileName;
                var attachmentURL = NSUrl.CreateFileUrl (cacheFile, false, null);

                NSFileManager.DefaultManager.Move(tempfile, attachmentURL, out err);
                if (err != null)
                {
                    ContentHandler (BestAttemptContent);
                    return;
                }

                // Create attachment;
                var attachmentID = "image";
                var options = new UNNotificationAttachmentOptions ();
                var attachment = UNNotificationAttachment.FromIdentifier (attachmentID, attachmentURL, options, out err);

                BestAttemptContent.Attachments = new UNNotificationAttachment [] { attachment };
                BestAttemptContent.Title = BestAttemptContent.Title;
                BestAttemptContent.Body = BestAttemptContent.Body;
                BestAttemptContent.CategoryIdentifier = BestAttemptContent.CategoryIdentifier;
                BestAttemptContent.Subtitle = BestAttemptContent.Subtitle;
                //Display notification
                ContentHandler (BestAttemptContent);
            });
            task.Resume ();

        } else {
            // Display notification
            ContentHandler (BestAttemptContent);
        }
    }

    public override void TimeWillExpire ()
    {
        // Called just before the extension will be terminated by the system.
        // Use this as an opportunity to deliver your "best attempt" at modified content, otherwise the original push payload will be used.
        ContentHandler (BestAttemptContent);
    }
}
}