ios AFNetworking 和无 Internet 连接方案

AFNetworking and No Internet Connection scenario

提问by Fred Collins

I use AFNetworkingin my app for every request (like login, get data from url, etc).

我AFNetworking在我的应用程序中使用每个请求（如登录、从 url 获取数据等）。

Take this for example: an user click on the login button and there's no connection, how to instantly display a UIAlertViewthat says the error? The onlyway is to wait the request timeout and execute the failureblock? Isn't there a way that instantly check if there's connection or not?

以这个为例：用户点击登录按钮并且没有连接，如何立即显示一个UIAlertView表示错误的信息？该唯一的办法就是等待请求超时并执行failure块？有没有一种方法可以立即检查是否有连接？

Thanks!

谢谢！

回答by mattt

As of 0.9, AFHTTPClientactually has network reachability built-in (a simpler interface to Apple's aforementioned Reachability code). Just include the SystemConfigurationframework and use -setReachabilityStatusChangeBlock:to specify a response when the reachability state changes.

从 0.9 开始，AFHTTPClient实际上内置了网络可达性（Apple 前面提到的可达性代码的更简单的接口）。只需包含SystemConfiguration框架并用于-setReachabilityStatusChangeBlock:在可达性状态更改时指定响应。

回答by Yogesh Agarwal

With AFNetworkingthese are the steps that one has to follow in order to take advantage of setReachabilityStatusChangeBlock:after adding the AFNetworing classes -

随着AFNetworking这些步骤一个是为了趁跟随setReachabilityStatusChangeBlock:加入AFNetworing班后-

1. Add SystemConfiguration.frameworkto your project
2. In pch file add #import <SystemConfiguration/SystemConfiguration.h>
3. Assuming that you have a subclass of AFHTTPClientin this subclass add below lines of code in init function -

1. 添加SystemConfiguration.framework到您的项目
2. 在 pch 文件中添加 #import <SystemConfiguration/SystemConfiguration.h>
3. 假设您AFHTTPClient在此子类中有一个子类，请在 init 函数中添加以下代码行 -

[self setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {
        NSLog(@"changed %d", status);
        //your code here
    }];

回答by carmen_munich

I use the AFNetworkingOperationDidFinishNotification. Every time a http request will fail, the alert pops up and informs the user

我使用AFNetworkingOperationDidFinishNotification. 每次http请求失败时，都会弹出alert并通知用户

- (void)addNetworkObserver
{
   [[NSNotificationCenter defaultCenter] addObserver:self
                                            selector:@selector(HTTPOperationDidFinish:) 
                                                name:AFNetworkingOperationDidFinishNotification 
                                              object:nil];
}

- (void)HTTPOperationDidFinish:(NSNotification *)notification 
{
   AFHTTPRequestOperation *operation = (AFHTTPRequestOperation *)[notification object];
   if (![operation isKindOfClass:[AFHTTPRequestOperation class]]) {
       return;
   }
   if (operation.error) {
       UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Connection error"
                                                       message:@"Missing connection to the internet"
                                                      delegate:nil
                                             cancelButtonTitle:@"OK"
                                             otherButtonTitles:nil];

       [alert show];
   }
}

回答by bs7

Maybe you could use "Reachability" to determine if the device is connected to the network. Here is the link to the Apple Doc. : Reachability

也许您可以使用“可达性”来确定设备是否已连接到网络。这是 Apple 文档的链接。:可达性

For example :

例如 ：

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(handleNetworkChange:) name:kReachabilityChangedNotification object:nil];
reachability = [Reachability reachabilityForInternetConnection];
[reachability startNotifier];
NetworkStatus remoteHostStatus = [reachability currentReachabilityStatus];
if(remoteHostStatus == NotReachable) {
  //Your UIAlertView
}

回答by Adam Eberbach

How about using Reachability?

如何使用可达性？

You can check whether you have a plausible reason for trying a connection before you do it.

在进行连接之前，您可以检查是否有合理的理由尝试连接。

Looks like the Apple Sample Project for Reachabilityshows how to get an initial status.

看起来像Apple Sample Project for Reachability展示了如何获得初始状态。