ios 實時監測網絡情況

-(void)reach
{
    /**
     AFNetworkReachabilityStatusUnknown          = -1,  // 未知
     AFNetworkReachabilityStatusNotReachable     = 0,   // 無鏈接
     AFNetworkReachabilityStatusReachableViaWWAN = 1,   // 3G 花錢
     AFNetworkReachabilityStatusReachableViaWiFi = 2,   // 局域網絡,不花錢
     */
    // 若是要檢測網絡狀態的變化,必須用檢測管理器的單例的startMonitoring
    [[AFNetworkReachabilityManager sharedManager] startMonitoring];
    
    // 檢測網絡鏈接的單例,網絡變化時的回調方法
    [[AFNetworkReachabilityManager sharedManager] setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {
#ifdef DEBUG
        NSLog(@"Reachability: %@", AFStringFromNetworkReachabilityStatus(status));
#endif
        if (status > 0)
            [UserDefaultsUtills setIsSwitchIsOn:YES];
        else
            [UserDefaultsUtills setIsSwitchIsOn:NO];
        
        if (status ==AFNetworkReachabilityStatusNotReachable) {
            
            [SVProgressHUD showErrorWithStatus:@"網絡異常,請檢查網絡設置!" duration:1.2];
            self.window.rootViewController=errovc;
        }
        
    }];
}

拷貝這個方法再appdelegate。m裏面，而後在- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {裏面調用就好了