iPhoneテストネットワークリンク

// internet   ， sockaddr_in sockaddr 。
    struct sockaddr_in zeroAddress;
    // zeroAddress 
	bzero(&zeroAddress, sizeof(zeroAddress));
	zeroAddress.sin_len = sizeof(zeroAddress);
	zeroAddress.sin_family = AF_INET; // 
    
    //    ip 
	SCNetworkReachabilityRef defaultRouteReachability = SCNetworkReachabilityCreateWithAddress(NULL, (struct sockaddr *)&zeroAddress);
    // 
	SCNetworkReachabilityFlags flags;
	
    // 
    
	BOOL didRetrieveFlags = SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags);
	CFRelease(defaultRouteReachability);
	
	if (!didRetrieveFlags) {
		printf("Error. Count not recover network reachability flags
");
	}
	//
	BOOL isReachable = flags & kSCNetworkFlagsReachable;
	BOOL needsConnection = flags & kSCNetworkFlagsConnectionRequired;
    
    NSString *result;
	if ((isReachable && !needsConnection) ? YES : NO) {
		result = @"Connection Successed!!!";
	}else {
		result = @"Connection Faild!!!";
	}
	UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"TestConnection" 
                                                    message:result
												   delegate:self
										  cancelButtonTitle:@"OK,I Know" 
                                          otherButtonTitles:nil];
	[alert show];

NSString *connectionKind;
    //  
    Reachability *hostReach = [Reachability reachabilityWithHostName:@"www.baidu.com"];
	//  
    switch ([hostReach currentReachabilityStatus]) {
		case NotReachable:
			connectionKind = @" ";
			break;
		case ReachableViaWiFi:
			connectionKind = @" WIFI";
			break;
		case ReachableViaWWAN:
			connectionKind = @" WWAN（3G）";
			break;
		default:
			break;
	}
	
	UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@" " 
                                                    message:connectionKind
												   delegate:self
										  cancelButtonTitle:@" ， " 
                                          otherButtonTitles:nil];
	[alert show];