26>AFN监控当前网络的状态

-(void)checkNetworking
{
    AFNetworkReachabilityManager *mgr = [AFNetworkReachabilityManager sharedManager];
    [mgr setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {
       // 当网络状态发生改变时，调用这个block
        switch (status) {
            case AFNetworkReachabilityStatusReachableViaWiFi:
                NSLog(@"当前是WIFI环境");
                break;
            case AFNetworkReachabilityStatusReachableViaWWAN:
                NSLog(@"当前是手机网络");
                break;
            case AFNetworkReachabilityStatusNotReachable:
                NSLog(@"当没有网络");
                break;
            case AFNetworkReachabilityStatusUnknown:
                NSLog(@"未知网络");
                break;
            default:
                break;
        }
    }];
    // 开始监控网络
    [mgr startMonitoring];
}