Question

我在应用程序运行时定期调用多个异步RESTful服务，以使某些数据保持最新。此外，我希望能够在收到针对此的推送通知时执行此类数据更新，因此我启用了远程通知的后台模式并实施了didReceiveRemoteNotification:fetchCompletionHandler:委托方法。

现在我的问题是：由于我的数据更新对多个Web服务执行异步调用，并且根据文档必须调用completionHandler方法的didReceiveRemoteNotification:fetchCompletionHandler:，我该如何处理？或者我是否要实现数据更新的同步版本？

由于

Answer 1

无需对数据更新Web服务进行同步调用。只要您的任务完成，只需致电completionHandler即可。基本上，您只需30秒即可完成更新工作。成功更新后，只需致电completionHandler

请看以下例如。

- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo fetchCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler
{
    // Here write logic as per your requirements, check userInfo for notification data

    // Following is http call for updation

    NSURLSessionConfiguration *configuration = [NSURLSessionConfiguration defaultSessionConfiguration];
    NSURLSession *session = [NSURLSession sessionWithConfiguration:configuration delegate:self delegateQueue:nil];

    NSURL *url = [NSURL URLWithString:@"YOUR URL"];


    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url
                                                           cachePolicy:NSURLRequestUseProtocolCachePolicy
                                                       timeoutInterval:30.0];

    [request addValue:@"application/json" forHTTPHeaderField:@"Content-Type"];
    [request setHTTPMethod:@"POST"];

    NSURLSessionDataTask *postDataTask = [session dataTaskWithRequest:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {

        NSLog(@"RESPONSE From Server: %@", response);

        // Do any updation work

        // Finally call comletionHandler
        completionHandler(UIBackgroundFetchResultNoData);
    }];

    [postDataTask resume];
}

didReceiveRemoteNotification：fetchCompletionHandler：和异步数据更新？

1 个答案: