这让我疯了，因为它以前从来没有发生在我身上，而且我做了几十次。
在两个视图控制器之间传递值会导致值为Traceback (most recent call last):
File "/usr/lib/python3.4/urllib/request.py", line 1182, in do_open
h.request(req.get_method(), req.selector, req.data, headers)
File "/usr/lib/python3.4/http/client.py", line 1088, in request
self._send_request(method, url, body, headers)
File "/usr/lib/python3.4/http/client.py", line 1126, in _send_request
self.endheaders(body)
File "/usr/lib/python3.4/http/client.py", line 1084, in endheaders
self._send_output(message_body)
File "/usr/lib/python3.4/http/client.py", line 922, in _send_output
self.send(msg)
File "/usr/lib/python3.4/http/client.py", line 857, in send
self.connect()
File "/usr/lib/python3.4/http/client.py", line 834, in connect
self.timeout, self.source_address)
File "/usr/lib/python3.4/socket.py", line 512, in create_connection
raise err
File "/usr/lib/python3.4/socket.py", line 503, in create_connection
sock.connect(sa)
TimeoutError: [Errno 110] Connection timed out
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/home/maxlagerz/PycharmProjects/AbitLogger/main.py", line 58, in <module>
main()
File "/home/maxlagerz/PycharmProjects/AbitLogger/main.py", line 53, in main
parse(get_html(url), url)
File "/home/maxlagerz/PycharmProjects/AbitLogger/main.py", line 22, in get_html
response = urllib.request.urlopen(url)
File "/usr/lib/python3.4/urllib/request.py", line 161, in urlopen
return opener.open(url, data, timeout)
File "/usr/lib/python3.4/urllib/request.py", line 463, in open
response = self._open(req, data)
File "/usr/lib/python3.4/urllib/request.py", line 481, in _open
'_open', req)
File "/usr/lib/python3.4/urllib/request.py", line 441, in _call_chain
result = func(*args)
File "/usr/lib/python3.4/urllib/request.py", line 1210, in http_open
return self.do_open(http.client.HTTPConnection, req)
File "/usr/lib/python3.4/urllib/request.py", line 1184, in do_open
raise URLError(err)
urllib.error.URLError: <urlopen error [Errno 110] Connection timed out>
。
我有一个NULL方法：
prepareForSegue:但是当执行segue时，我尝试记录- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
if ([segue.identifier isEqualToString: @"LoginSegue"]) {
UITabBarController *destinationTabController = [segue destinationViewController];
ViewController *destinationViewController = destinationTabController.selectedViewController;
NSLog(@"Logged user is %@.", loggedUser); //This prints out the user correctly
destinationViewController.currentUser = loggedUser;
}
}
值，它是currentUser。
任何想法，伙计们？
答案 0 :(得分：2)
标签栏控制器不在界面中，因此未选择任何内容。因此，destinationViewController为nil，您尝试设置其currentUser无效。