iOS 10新的通知机制中添加图片的方法详解

//// NotificationService.swift// NotificationServiceExtension//// Created by Heyuan Li on 17/2/26.// Copyright © 2017年 fenbi. All rights reserved.// import UserNotifications class NotificationService: UNNotificationServiceExtension {  var contentHandler: ((UNNotificationContent) -> Void)? var bestAttemptContent: UNMutableNotificationContent?  override func didReceive(_ request: UNNotificationRequest, withContentHandler contentHandler: @escaping (UNNotificationContent) -> Void) {  self.contentHandler = contentHandler  bestAttemptContent = (request.content.mutableCopy() as? UNMutableNotificationContent)    if let bestAttemptContent = bestAttemptContent {   // Modify the notification content here...   bestAttemptContent.title = "上课啦"    if let imageURLString = bestAttemptContent.userInfo["image"] as? String,    let URL = URL(string: imageURLString)   {    downloadAndSave(url: URL) { localURL in     if let localURL = localURL {      do {       let attachment = try UNNotificationAttachment(identifier: "image_downloaded", url: localURL, options: nil)       bestAttemptContent.attachments = [attachment]      } catch {       print(error)      }     }     contentHandler(bestAttemptContent)    }   }  } }  override func serviceExtensionTimeWillExpire() {  // 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.  if let contentHandler = contentHandler, let bestAttemptContent = bestAttemptContent {   contentHandler(bestAttemptContent)  } }  private func downloadAndSave(url: URL, handler: @escaping (_ localURL: URL?) -> Void) {  let task = URLSession.shared.dataTask(with: url, completionHandler: {   data, res, error in    var localURL: URL? = nil    if let data = data {    let ext = (url.absoluteString as NSString).pathExtension    let cacheDirs = FileManager.default.urls(for: .cachesDirectory, in: .userDomainMask)    if cacheDirs.count > 0 {     let cacheDir = cacheDirs[cacheDirs.count - 1]     /// TODO tutor cache     /// TODO md5 extension      let url = cacheDir.appendingPathComponent("123").appendingPathExtension(ext)       if let _ = try? data.write(to: url) {       localURL = url      }    }   }      handler(localURL)  })    task.resume() } }

{ "aps": { "alert": "instant message from CRM", "sound": "default",  "mutable-content": 1 },...... "image": "https://g0.fbcontent.cn/api/tutor/images/153c6c68411747f.jpg"}