我正在尝试在iOS应用中创建一个身份验证系统，该系统允许用户登录和注册(如果他们还没有帐户)。我昨天完成了登录系统的运行，但是当我为注册系统设置了代码时，该代码甚至无法ping通服务器。然后，我尝试再次测试登录系统，该代码现在也无法ping通服务器。

RegistrationTableViewController的相关代码(这是一个自定义TVC，在某些单元格中包含文本字段-例如，请考虑使用该视图来创建新的日历事件):

- (IBAction)signUpButtonPressed { 
    // Get the values out of the text fields that the user has filled out.
    NSString *email = self.emailTextField.text;
    NSString *firstName = self.firstNameTextField.text;
    NSString *lastName = self.lastNameTextField.text;
    NSString *password = self.passwordTextField.text;
    // Assuming that sign-up could potentially take a noticeable amount of time, run the
    // process on a separate thread to avoid locking the UI.
    dispatch_queue_t signUpQueue = dispatch_queue_create("sign-up authenticator", NULL);
    dispatch_async(signUpQueue, ^{
        // self.brain refers to a SignUpBrain property. See the code for the class below.
        [self.brain signUpUsingEmail:email firstName:firstName lastName:lastName  
          andPassword:password];  
        dispatch_async(dispatch_get_main_queue(), ^{  
            [self performSegueWithIdentifier:@"ShowMainFromSignUp" sender:self];  
        });  
    });  
    dispatch_release(signUpQueue);  
}

- (void)signUpUsingEmail:(NSString *)email firstName:(NSString *)firstName
                lastName:(NSString *)lastName andPassword:(NSString *)password {
    self.email = email;
    self.firstName = firstName;
    self.lastName = lastName;
    self.password = password;

    // Handle sign-up web calls.
    NSMutableURLRequest *signUpRequest = [[NSMutableURLRequest alloc] initWithURL:[NSURL 
      URLWithString:@"URL GOES HERE"]]; // obviously there's an actual URL in real code
    NSString *postString = [NSString stringWithFormat:@"uname=%@&pw=%@&fname=%@&lname=%@", 
      email, password, firstName, lastName];
//NSLog(postString);
    [signUpRequest setHTTPMethod:@"POST"];
    [signUpRequest setHTTPBody:[postString dataUsingEncoding:NSUTF8StringEncoding]];
    NSURLConnection *signUpConnection = 
      [NSURLConnection connectionWithRequest:signUpRequest delegate:self];
    [signUpConnection start];

    // Store any user data.
}

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
    self.signUpResponse = data;
    NSError *error;
    NSDictionary *jsonLoginResults = [NSJSONSerialization JSONObjectWithData:data 
      options:0 error:&error];
    if (error) {
        NSLog(error.description);
    }
    NSLog(jsonLoginResults.description);

    // Return whether the user has successfully been registered.
    // If success is 1, then registration has been completed successfully. 0 if not.
    if ([jsonLoginResults objectForKey:@"status"]) {
        NSLog(@"Success!");
    }
}

最佳答案

通常情况下，您无需在其他线程上运行网络操作。

您需要避免的是在主线程上进行同步操作。这将导致iOS终止您的应用程序，因为它会在网络传输繁忙时停止响应事件。

苹果的建议是在主线程上使用异步操作，而不是在另一个线程上使用同步操作。

使用异步操作将导致网络本身在后台运行。您可以将其视为Apple的专用线程。当iOS认为合适时，将在主线程上以正确的顺序调用您的委托方法，以赶上网络。

使用NSURLConnection

Apple在《 URL加载系统编程指南》 Using NSURLConnection中提供了有关如何使用NSURLConnection的示例。这是一篇简短的文章，其中包含许多简单的代码示例。您应该花几分钟来阅读此内容。

简而言之，这是模式:

- (void)signUpUsingEmail:(NSString *)email firstName:(NSString *)firstName
                lastName:(NSString *)lastName andPassword:(NSString *)password {

    // set up your connection here, but don't start it yet.

    receivedData = [[NSMutableData alloc] init]; // receivedData should be a class member
    [signUpConnection start];
}

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
    [receivedData setLength:0];
}

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
    [receivedData appendData:data];
}

- (void)connection:(NSURLConnection *)connection
  didFailWithError:(NSError *)error {
    // do something with error here
    // if you're not using ARC, release connection & receivedData here
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
    dispatch_async(someQueue, ^{
        // do something that takes a long time with receivedData here
        dispatch_async( dispatch_get_main_queue(), ^{
            // go back to your main screen here
        });
    });
    // if you're not using ARC, release connection & receivedData here
}

HTTPOperation = [[AFHTTPRequestOperation alloc] initWithRequest: URLRequest];
HTTPOperation.completionBlock = ^{
    dispatch_async(someQueue, ^{
        // get possible error or content from HTTPOperation
    }
};
[HTTPOperation start];

关于objective-c - iOS RESTful POST调用在UIWebView中有效，但从线程调用时无效，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/10745510/