objective-c - 如何确定 Cocoa 中的 Internet 连接？

Question

我需要确定 Internet 连接是否可用。我不在乎它是如何连接的(WI-FI、Lan 等)。我需要确定 Internet 连接是否可用。

附言我找到了一种检查 WI-FI 连接的方法。但我不关心它是如何连接的(我需要检查所有可以连接到互联网的方式)。

类似(已连接)

Answer 1

我希望这段代码适用于 iOS 和 OSX 平台。

#include <SystemConfiguration/SystemConfiguration.h>
static BOOL isInternetConnection()
{
    BOOL returnValue = NO;

#ifdef TARGET_OS_MAC

    struct sockaddr zeroAddress;
    bzero(&zeroAddress, sizeof(zeroAddress));
    zeroAddress.sa_len = sizeof(zeroAddress);
    zeroAddress.sa_family = AF_INET;

    SCNetworkReachabilityRef reachabilityRef = SCNetworkReachabilityCreateWithAddress(NULL, (const struct sockaddr*)&zeroAddress);


#elif TARGET_OS_IPHONE

    struct sockaddr_in address;
    size_t address_len = sizeof(address);
    memset(&address, 0, address_len);
    address.sin_len = address_len;
    address.sin_family = AF_INET;

    SCNetworkReachabilityRef reachabilityRef = SCNetworkReachabilityCreateWithAddress(NULL, (const struct sockaddr*)&address);

#endif

    if (reachabilityRef != NULL)
    {
        SCNetworkReachabilityFlags flags = 0;

        if(SCNetworkReachabilityGetFlags(reachabilityRef, &flags))
        {
            BOOL isReachable = ((flags & kSCNetworkFlagsReachable) != 0);
            BOOL connectionRequired = ((flags & kSCNetworkFlagsConnectionRequired) != 0);
            returnValue = (isReachable && !connectionRequired) ? YES : NO;
        }

        CFRelease(reachabilityRef);
    }

    return returnValue;

}