I was getting this error as well, but on actual devices rather than the simulator. We noticed the error when accessing our heroku backend on HTTPS (gunicorn server), and doing POSTS with large bodys (anything over 64Kb). We use HTTP Basic Auth for authentication, and noticed the error was resolved by NOT using the didReceiveChallenge: delegate method on NSURLSession, but rather baking in the Authentication into the original request header via adding Authentiation: Basic <Base64Encoded UserName:Password>. This prevents the necessary 401 to trigger the didReceiveChallenge: delegate message, and the subsequent network connection lost.

I was getting this error as well, but on actual devices rather than the simulator. We noticed the error when accessing our heroku backend on HTTPS (gunicorn server), and doing POSTS with large bodys (anything over 64Kb). We use HTTP Basic Auth for authentication, and noticed the error was resolved by NOT using the didReceiveChallenge: delegate method on NSURLSession, but rather baking in the Authentication into the original request header via adding Authentiation: Basic <Base64Encoded UserName:Password>. This prevents the necessary 401 to trigger the didReceiveChallenge: delegate message, and the subsequent network connection lost.

无论何时得到错误-1005，然后需要再次调用API。

AFHTTPRequestOperationManager *manager = 
[AFHTTPRequestOperationManager manager];
[manager setSecurityPolicy:policy];
manager.requestSerializer = [AFHTTPRequestSerializer serializer];
manager.responseSerializer = [AFHTTPResponseSerializer serializer];

[manager POST:<example-url>
   parameters:<parameteres>
    success:^(AFHTTPRequestOperation *operation, id responseObject) {
      NSLog(@“Success: %@", responseObject);
  } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
      NSLog(@"Error: %@", error);
      if (error.code == -1005) {
          // Call method again... 
       }
  }];

您需要再次添加调用函数的代码。确保你是调用方法一次，否则它的调用循环递归。

我也有同样的问题，问题是Alomofire和NSUrlSession的bug。当你从safari或电子邮件返回到应用程序时，你需要等待近2秒才能通过Alamofire进行网络响应

 DispatchQueue.main.asyncAfter(deadline: .now() + 2) {
       Your network response
}

2017年1月25日，苹果发布了一份关于此错误的技术问答:

Apple Technical Q&A QA1941 Handling “The network connection was lost” Errors A: NSURLErrorNetworkConnectionLost is error -1005 in the NSURLErrorDomain error domain, and is displayed to users as “The network connection was lost”. This error means that the underlying TCP connection that’s carrying the HTTP request disconnected while the HTTP request was in progress (see below for more information about this). In some circumstances NSURLSession may retry such requests automatically (specifically, if the request is idempotent) but in other circumstances that’s not allowed by the HTTP standards. https://developer.apple.com/library/archive/qa/qa1941/_index.html#//apple_ref/doc/uid/DTS40017602

我在使用Alamofire时遇到了这个问题。我的错误是我在GET请求中发送了一个空字典[:]作为参数，而不是发送nil参数。

希望这能有所帮助!