IOS: network detection

If you want the app to pass the review, you must determine the network environment and handle alerts when there is no network.

Apple's routine reachability describes how to obtain/detect the network status. To be appliedProgramTo use Reachability in a program, you must first complete the following two parts:
    
    1.1. Add the source file:
    In your programUse ReachabilityYou only need to copy the reachability. h and reachability. m in this routine to your project. For example:

       
       
        1. 2. Add the framework:
        Set systemconfiguration. Framework Add to project. For example:
       
       
        2. Network Status
       
        Three Network statuses are defined in reachability. h:
        Typedef Enum {
                Notreachable = 0,                       // No connection
                Reachableviawifi,                       // Use a 3G/GPRS network
                Reachableviawwan                       // Use a Wi-Fi network
        } Networkstatus;
       
        Therefore, you can check the network status as follows:

        Reachability * r = [reachability reachabilitywithhostname : @" Www.apple.com "];
        Switch ([R currentreachabilitystatu S]) {
                        Case notreachable:
                                        // No network connection
                                        Break;
                        Case reachableviawwan:
                                        // Use a 3G network
                                        Break;
                        Case reachableviawifi:
                                        // Use a Wi-Fi network
                                        Bre AK;
        }

Check: http://blog.sina.com.cn/s/blog_6f40a0e70100srip.html