判断网络连接

首先，需要把SystemConfiguration.framework加入到项目中。

 

CheckNetwork.h

 

#import <Foundation/Foundation.h>

@interface CheckNetwork : NSObject {
    
}

+ (BOOL) connectedToNetwork;

@end

 

CheckNetwork.m

 

#import "CheckNetwork.h"
#import <netinet/in.h>
#import <SystemConfiguration/SCNetworkReachability.h>

@implementation CheckNetwork

+ (BOOL) connectedToNetwork {
	struct sockaddr_in zeroAddress;
	bzero(&zeroAddress, sizeof(zeroAddress));
	zeroAddress.sin_len = sizeof(zeroAddress);
    zeroAddress.sin_family = AF_INET;	
	SCNetworkReachabilityRef defaultRouteReachability = SCNetworkReachabilityCreateWithAddress(NULL, (struct sockaddr *)&zeroAddress);
	SCNetworkReachabilityFlags flags;
	BOOL didRetrieveFlags = SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags);
	CFRelease(defaultRouteReachability);
	if (!didRetrieveFlags) {
		return NO;
	}	
    BOOL isReachable = flags & kSCNetworkFlagsReachable;
	BOOL needsConnection = flags & kSCNetworkFlagsConnectionRequired;
	BOOL isWWAN = flags & kSCNetworkReachabilityFlagsIsWWAN;
	return (isReachable && (!needsConnection || isWWAN)) ? YES : NO;
}

@end