新增http協議支援，沒錯，這裡是支援http協議的，不像其他文章說的不支援，配置在另外基礎篇文章裡面有，info.plist檔案裡修改一下就行了

NotificationService檔案

額外添加了一個檔案管理器的欄位，用來儲存資料

@interface NotificationService ()

@property (nonatomic, strong) void (^contentHandler)(UNNotificationContent *contentToDeliver);
@property (nonatomic, strong) UNMutableNotificationContent *bestAttemptContent;
@property
 
 (nonatomic, strong) NSFileManager *fileMgr;
@property (nonatomic, strong) NSURLSessionDownloadTask *download;
@property (nonatomic, strong) NSURLSession *session;
@property (nonatomic, strong) NSDictionary *userInfo;
@property (nonatomic, strong) NSURL *attchUrl;
@property (nonatomic, strong) NSString
 
 *imageExtension;
@end

@implementation NotificationService

LazyLoad

-(NSFileManager *)fileMgr{
    return [NSFileManager defaultManager];
}

網路session

-(NSURLSession *)session{
    if (_session == nil) {
        _session = [NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration]];
    }
    return
 
 _session;
}

下載任務

-(NSURLSessionDownloadTask *)download{
    if (!_download) {
       _download = [self.session downloadTaskWithURL:self.attchUrl completionHandler:^(NSURL * _Nullable tempLocation, NSURLResponse * _Nullable response, NSError * _Nullable error) {
            if (!error) {
                NSURL *localURL = [NSURL fileURLWithPath:[tempLocation.path stringByAppendingString:self.imageExtension]];
                [self.fileMgr moveItemAtURL:tempLocation toURL:localURL error:&error];
                NSError *attachmentError = nil;
                UNNotificationAttachment * attachment = [UNNotificationAttachment attachmentWithIdentifier:@"photo" URL:localURL options:nil error:&attachmentError];
                if (attachmentError) {
                    NSLog(@"attachmentError %@",attachmentError);
                }else if (attachment){
                    self.bestAttemptContent.attachments = @[attachment];
                }else{

                }
            }else{
                NSLog(@"downloadTaskerror %@",error.localizedDescription);
            }
            self.bestAttemptContent.categoryIdentifier = self.userInfo[@"aps"][@"category"];
            self.contentHandler(self.bestAttemptContent);
        }];
    }
    return _download;
}

收到遠端通知之後，在當前方法內進行處理，並生成attchment，最終回撥給系統

- (void)didReceiveNotificationRequest:(UNNotificationRequest *)request withContentHandler:(void (^)(UNNotificationContent * _Nonnull))contentHandler {
   self.contentHandler = contentHandler;
    self.bestAttemptContent = [request.content mutableCopy];
    self.resumeTime = 0;
    self.userInfo = [request.content.userInfo copy];
    NSString * attchUrl = self.userInfo[@"image"];
    self.imageExtension = [NSString stringWithFormat:@".%@",[[attchUrl componentsSeparatedByString:@"."] lastObject]];
    if (attchUrl) {
        self.attchUrl = [NSURL URLWithString:attchUrl];
        [self resumeSession];
    }
}

開始執行下載多媒體資源任務

- (void)resumeSession{
    [self.download resume];
}

超時，異常時呼叫

- (void)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.


    self.contentHandler(self.bestAttemptContent);
}

@end