相关疑难解决方法(0)

我正在从一个非常慢的服务器上下载JSON数据.从服务器获得一个resoonse大约需要一分钟.我使用AFNetworking库,我的代码抛出"请求超时"错误:

NSString *urlString = [NSString stringWithFormat:@"%@/account.do?JSON&sysparm_action=getRecords",baseUrlString];

    NSString *login = [[NSUserDefaults standardUserDefaults] objectForKey:@"login"];
    NSString *password = [[NSUserDefaults standardUserDefaults] objectForKey:@"password"];

    [manager setRequestSerializer:[AFHTTPRequestSerializer serializer]];
    [manager.requestSerializer setAuthorizationHeaderFieldWithUsername:login password:password];


    [manager GET:urlString parameters:nil success:^(AFHTTPRequestOperation *operation, id responseObject) {
        NSLog(@"JSON: %@", responseObject);
        [self parseJsonWithAccountsData:responseObject];
    } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
        NSLog(@"Error: %@", operation.responseString);
        [self performSelectorOnMainThread:@selector(failedWithContactsDownload) withObject:nil waitUntilDone:YES];
    }];

没有找到设置超时的方法AFHTTPRequestOperationManager.我该怎么做？