iPhone判断当前网络连接状态

导入头文件

#include 
#import 

判断网络连接状态

//判断当前网络连接状态
-(BOOL)isNetworkAvailable
{
    //创建零地址，0.0.0.0的地址表示查询本机的网络连接状态
    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;
    
    //获得连接的标志
    BOOL didRetrieveFlags = SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags);
    CFRelease(defaultRouteReachability);
    
    //如果不能获取连接标志，则不能连接网络，直接返回
    if (!didRetrieveFlags)
    {
        return NO;
    }
    
    //根据获得的连接标志进行判断
    BOOL isReachable = flags & kSCNetworkFlagsReachable;
    BOOL needsConnection = flags & kSCNetworkFlagsConnectionRequired;
    return (isReachable && !needsConnection) ? YES : NO;
    
}