用Cocoa Pods导入控件以后 直接导头文件 复制以下代码[SCNetworkReachability host:@"github.com" reachabilityStatus:^(SCNetworkStatus status){    switch (status)    {        case SCNetworkStatusReachableViaWiFi:            NSLog(@"Reachable via WiFi");            break;        case SCNetworkStatusReachableViaCellular:            NSLog(@"Reachable via Cellular");            break;        case SCNetworkStatusNotReachable:            NSLog(@"Not Reachable");            break;    }}];