iOS学习之判断是否有网络的方法
在实际开发中, 会有这样一个需求: 用户在有网的状态下会直接从网络请求数据, 在没网的情况下直接从本地读取数据.
下边的方法可以判断是否有网络.
- (BOOL)connectedToNetwork { // Create zero addy struct sockaddr_in zeroAddress; bzero(&zeroAddress, sizeof(zeroAddress)); zeroAddress.sin_len = sizeof(zeroAddress); zeroAddress.sin_family = AF_INET; // Recover reachability flags SCNetworkReachabilityRef defaultRouteReachability = SCNetworkReachabilityCreateWithAddress(NULL, (struct sockaddr *)&zeroAddress); SCNetworkReachabilityFlags flags; BOOL didRetrieveFlags = SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags); CFRelease(defaultRouteReachability); if (!didRetrieveFlags) { printf("Error. Could not recover network reachability flags\n"); return NO; } BOOL isReachable = ((flags & kSCNetworkFlagsReachable) != 0); BOOL needsConnection = ((flags & kSCNetworkFlagsConnectionRequired) != 0); return (isReachable && !needsConnection) ? YES : NO; }
在文件中可以将该文件复制其中, 该方法有一个BOOL类型的返回值, 只需要根据返回值来执行的具体的操作即可.