在通知服务中设置附件无效

Question

我正在尝试自定义通知的默认设计，文本设置工作正常。但是，当我尝试添加附件时，通知不会显示附件。下面是我的didRecive方法。根据教程，他们只是这样做。我可以使用

获取图像的网址

let url = Bundle.main.url(forResource: "download", withExtension: "png")

但是当我添加附件时，整个通知设置为默认。

override func didReceive(_ request: UNNotificationRequest, withContentHandler contentHandler: @escaping (UNNotificationContent) -> Void) {
        self.contentHandler = contentHandler
        bestAttemptContent = (request.content.mutableCopy() as? UNMutableNotificationContent)
        print("Notification Service")
        if let bestAttemptContent = bestAttemptContent {
            // Modify the notification content here...
          let data : [String : Any] = request.content.userInfo as! [String : Any]

          let badgeCount : Int = data["badgeCount"] as? Int ?? 0
          let notification : [String : Any]? = data["notification"] as? [String : Any]


          bestAttemptContent.badge = NSNumber(integerLiteral: badgeCount)

          if (notification != nil) {
            bestAttemptContent.title            = notification!["title"] as! String
            bestAttemptContent.body             = notification!["body"] as! String
          }

          let url = Bundle.main.url(forResource: "download", withExtension: "png")
          let attach = try! UNNotificationAttachment(identifier: "xyzzz", url: url!, options: nil)
          bestAttemptContent.attachments = [attach]


          contentHandler(bestAttemptContent)
        }
    }

图片尺寸为：900 * 900

查看此图片