这和AFNetworking没有关系，code=-1012 是系统提供 NSURLError 的错误信息。这有对照表http://blog.csdn.net/yesjava/article/details/8056681。
NSURLErrorUserCancelledAuthentication = -1012。用户取消验证。
搜搜就知道原因了。

1.无线访问和蜂窝访问的DNS服务器不一样. 看报错信息,你访问的服务器开启了SSL,使用了自生成的证书.
2.AFNetworking 2.x 我没有遇到过类似问题，在3.x版本下:
2.1 代码修改：

//使用默认的security policy, 注释掉类似代码： //sessionMgr.securityPolicy = [AFSecurityPolicy policyWithPinningMode:AFSSLPinningModeNone]; //以下和AFNetworking 2.x相同 sessionMgr.securityPolicy.allowInvalidCertificates = YES; //以下是AFNetworking 3.x 下需要的 sessionMgr.securityPolicy.validatesDomainName = NO;

2.2 Info.plist 加入ATS：

NSAppTransportSecurity  NSAllowsArbitraryLoads  

3.代码举例：

//#自生成证书 -(IBAction)clickOnSSLWithJSON:(id)sender { NSLog(@"ssl with json"); NSURL *url = [NSURL URLWithString:@"https://192.168.1.6:3000"]; AFHTTPSessionManager *sessionMgr=[[AFHTTPSessionManager alloc]initWithBaseURL:url]; sessionMgr.responseSerializer = [AFHTTPResponseSerializer serializer]; sessionMgr.responseSerializer.acceptableContentTypes = [[NSSet alloc] initWithObjects:@"text/html",nil]; //in this case, Info.plist should be added with keys 'NSAppTransportPolicy' and 'NSAllowsArbitraryLoads', //and security policy should be used with default. //following setting is same as AFNetworking 2.x sessionMgr.securityPolicy.allowInvalidCertificates = YES; //following setting is specified for AFNetworking 3.x sessionMgr.securityPolicy.validatesDomainName = NO; [sessionMgr GET:@"" parameters:nil progress:nil success: ^(NSURLSessionDataTask * _Nonnull task, id _Nullable result){ //NSUTF8StringEncoding should be encoded for response data. NSLog(@"ok:\n%@",[[NSString alloc]initWithData:result encoding:NSUTF8StringEncoding]); } failure:^(NSURLSessionDataTask * _Nullable task, NSError * _Nonnull error) { NSLog(@"error:\n%@",error); }]; }