98 AFNetworking網絡狀態監控

1>AFN網絡狀態監控：
- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

    AFNetworkReachabilityManager *mgr = [AFNetworkReachabilityManager sharedManager];
    [mgr setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {
        // 當網絡狀態發生改變的時候調用這個block
        switch (status) {
            case AFNetworkReachabilityStatusReachableViaWiFi:
                NSLog(@"WIFI");
                break;

            case AFNetworkReachabilityStatusReachableViaWWAN:
                NSLog(@"自帶網絡");
                break;

            case AFNetworkReachabilityStatusNotReachable:
                NSLog(@"沒有網絡");
                break;

            case AFNetworkReachabilityStatusUnknown:
                NSLog(@"未知網絡");
                break;
            default:
                break;
        }
    }];
    // 開始監控
    [mgr startMonitoring];

    //主動獲得網絡狀態
    mgr.isReachable;
    mgr.isReachableViaWiFi;
    mgr.isReachableViaWWAN;
}