iOS开发-Reachability实时检测Wifi,2G/3G/4G/网络状态

#import <Foundation/Foundation.h>
#import <SystemConfiguration/SystemConfiguration.h>
#import <netinet/in.h>//http://www.cnblogs.com/xiaofeixiang
typedef enum : NSInteger {
NotReachable = 0,
ReachableViaWiFi,
ReachableViaWWAN
} NetworkStatus;extern NSString *kReachabilityChangedNotification;@interface Reachability : NSObject/*!
* Use to check the reachability of a given host name.
*/
+ (instancetype)reachabilityWithHostName:(NSString *)hostName;/*!
* Use to check the reachability of a given IP address.
*/
+ (instancetype)reachabilityWithAddress:(const struct sockaddr_in *)hostAddress;/*!
* Checks whether the default route is available. Should be used by applications that do not connect to a particular host.
*/
+ (instancetype)reachabilityForInternetConnection;/*!
* Checks whether a local WiFi connection is available.
*/
+ (instancetype)reachabilityForLocalWiFi;/*!
* Start listening for reachability notifications on the current run loop.
*/
- (BOOL)startNotifier;
- (void)stopNotifier;- (NetworkStatus)currentReachabilityStatus;/*!
* WWAN may be available, but not active until a connection has been established. WiFi may require a connection for VPN on Demand.
*/
- (BOOL)connectionRequired;@end

#import <arpa/inet.h>
#import <ifaddrs.h>
#import <netdb.h>
#import <sys/socket.h>
#import <CoreFoundation/CoreFoundation.h>
#import "Reachability.h"NSString *kReachabilityChangedNotification = @"kNetworkReachabilityChangedNotification";#pragma mark - Supporting functions#define kShouldPrintReachabilityFlags 1static void PrintReachabilityFlags(SCNetworkReachabilityFlags flags, const char* comment)
{
#if kShouldPrintReachabilityFlags NSLog(@"Reachability Flag Status: %c%c %c%c%c%c%c%c%c %s\n",
//当前网络2G/3G/4G蜂窝网络
(flags & kSCNetworkReachabilityFlagsIsWWAN)? 'W' : '-',
//网络是否可达
(flags & kSCNetworkReachabilityFlagsReachable) ? 'R' : '-', (flags & kSCNetworkReachabilityFlagsTransientConnection) ? 't' : '-',
(flags & kSCNetworkReachabilityFlagsConnectionRequired) ? 'c' : '-',
(flags & kSCNetworkReachabilityFlagsConnectionOnTraffic) ? 'C' : '-',
(flags & kSCNetworkReachabilityFlagsInterventionRequired) ? 'i' : '-',
(flags & kSCNetworkReachabilityFlagsConnectionOnDemand) ? 'D' : '-',
(flags & kSCNetworkReachabilityFlagsIsLocalAddress) ? 'l' : '-',
(flags & kSCNetworkReachabilityFlagsIsDirect) ? 'd' : '-',
comment
);
#endif
}static void ReachabilityCallback(SCNetworkReachabilityRef target, SCNetworkReachabilityFlags flags, void* info)
{
#pragma unused (target, flags)
NSCAssert(info != NULL, @"info was NULL in ReachabilityCallback");
NSCAssert([(__bridge NSObject*) info isKindOfClass: [Reachability class]], @"info was wrong class in ReachabilityCallback");
//http://www.cnblogs.com/xiaofeixiang
Reachability* noteObject = (__bridge Reachability *)info;
// Post a notification to notify the client that the network reachability changed.
[[NSNotificationCenter defaultCenter] postNotificationName: kReachabilityChangedNotification object: noteObject];
}#pragma mark - Reachability implementation@implementation Reachability
{
BOOL _alwaysReturnLocalWiFiStatus; //default is NO
SCNetworkReachabilityRef _reachabilityRef;
}
//通过域名进行实例化 博客园-Fly_Elephant
+ (instancetype)reachabilityWithHostName:(NSString *)hostName
{
Reachability* returnValue = NULL;
SCNetworkReachabilityRef reachability = SCNetworkReachabilityCreateWithName(NULL, [hostName UTF8String]);
if (reachability != NULL)
{
returnValue= [[self alloc] init];
if (returnValue != NULL)
{
returnValue->_reachabilityRef = reachability;
returnValue->_alwaysReturnLocalWiFiStatus = NO;
}
}
return returnValue;
}//通过ip地址实例化Reachability
+ (instancetype)reachabilityWithAddress:(const struct sockaddr_in *)hostAddress
{
SCNetworkReachabilityRef reachability = SCNetworkReachabilityCreateWithAddress(kCFAllocatorDefault, (const struct sockaddr *)hostAddress);Reachability* returnValue = NULL;if (reachability != NULL)
{
returnValue = [[self alloc] init];
if (returnValue != NULL)
{
returnValue->_reachabilityRef = reachability;
returnValue->_alwaysReturnLocalWiFiStatus = NO;
}
}
return returnValue;
}//检测是否能够直接连上互联网
+ (instancetype)reachabilityForInternetConnection
{
struct sockaddr_in zeroAddress;
bzero(&zeroAddress, sizeof(zeroAddress));
zeroAddress.sin_len = sizeof(zeroAddress);
zeroAddress.sin_family = AF_INET;return [self reachabilityWithAddress:&zeroAddress];
}//检测当前网络是否能够联上wifi
+ (instancetype)reachabilityForLocalWiFi
{
struct sockaddr_in localWifiAddress;
bzero(&localWifiAddress, sizeof(localWifiAddress));
localWifiAddress.sin_len = sizeof(localWifiAddress);
localWifiAddress.sin_family = AF_INET;// IN_LINKLOCALNETNUM is defined in <netinet/in.h> as 169.254.0.0.
localWifiAddress.sin_addr.s_addr = htonl(IN_LINKLOCALNETNUM);Reachability* returnValue = [self reachabilityWithAddress: &localWifiAddress];
if (returnValue != NULL)
{
returnValue->_alwaysReturnLocalWiFiStatus = YES;
}return returnValue;
}#pragma mark - Start and stop notifier- (BOOL)startNotifier
{
BOOL returnValue = NO;SCNetworkReachabilityContext context = {0, (__bridge void *)(self), NULL, NULL, NULL};
//SCNetworkReachabilitySetCallback函数为指定一个target
//当设备对于这个target链接状态发生改变时(比如断开链接，或者重新连上)，则回调reachabilityCallback函数，
if (SCNetworkReachabilitySetCallback(_reachabilityRef, ReachabilityCallback, &context))
{
if (SCNetworkReachabilityScheduleWithRunLoop(_reachabilityRef, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode))
{
returnValue = YES;
}
}return returnValue;
}- (void)stopNotifier
{
if (_reachabilityRef != NULL)
{
SCNetworkReachabilityUnscheduleFromRunLoop(_reachabilityRef, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode);
}
}- (void)dealloc
{
[self stopNotifier];
if (_reachabilityRef != NULL)
{
CFRelease(_reachabilityRef);
}
}#pragma mark - Network Flag Handling- (NetworkStatus)localWiFiStatusForFlags:(SCNetworkReachabilityFlags)flags
{
PrintReachabilityFlags(flags, "localWiFiStatusForFlags");
NetworkStatus returnValue = NotReachable;if ((flags & kSCNetworkReachabilityFlagsReachable) && (flags & kSCNetworkReachabilityFlagsIsDirect))
{
returnValue = ReachableViaWiFi;
}return returnValue;
}- (NetworkStatus)networkStatusForFlags:(SCNetworkReachabilityFlags)flags
{
PrintReachabilityFlags(flags, "networkStatusForFlags");
if ((flags & kSCNetworkReachabilityFlagsReachable) == 0)
{
// The target host is not reachable.
return NotReachable;
} NetworkStatus returnValue = NotReachable;if ((flags & kSCNetworkReachabilityFlagsConnectionRequired) == 0)
{
/*
If the target host is reachable and no connection is required then we'll assume (for now) that you're on Wi-Fi...
*/
returnValue = ReachableViaWiFi;
}if ((((flags & kSCNetworkReachabilityFlagsConnectionOnDemand ) != 0) ||
(flags & kSCNetworkReachabilityFlagsConnectionOnTraffic) != 0))
{
/*
... and the connection is on-demand (or on-traffic) if the calling application is using the CFSocketStream or higher APIs...
*/ if ((flags & kSCNetworkReachabilityFlagsInterventionRequired) == 0)
{
/*
... and no [user] intervention is needed...
*/
returnValue = ReachableViaWiFi;
}
}if ((flags & kSCNetworkReachabilityFlagsIsWWAN) == kSCNetworkReachabilityFlagsIsWWAN)
{
/*
... but WWAN connections are OK if the calling application is using the CFNetwork APIs.
*/
returnValue = ReachableViaWWAN;
}return returnValue;
}- (BOOL)connectionRequired
{
NSAssert(_reachabilityRef != NULL, @"connectionRequired called with NULL reachabilityRef");
SCNetworkReachabilityFlags flags;if (SCNetworkReachabilityGetFlags(_reachabilityRef, &flags))
{
return (flags & kSCNetworkReachabilityFlagsConnectionRequired);
} return NO;
}//获取当前网络状态
- (NetworkStatus)currentReachabilityStatus
{
NSAssert(_reachabilityRef != NULL, @"currentNetworkStatus called with NULL SCNetworkReachabilityRef");
NetworkStatus returnValue = NotReachable;
SCNetworkReachabilityFlags flags;if (SCNetworkReachabilityGetFlags(_reachabilityRef, &flags))
{
if (_alwaysReturnLocalWiFiStatus)
{
returnValue = [self localWiFiStatusForFlags:flags];
}
else
{
returnValue = [self networkStatusForFlags:flags];
}
}return returnValue;
}@end

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
//添加一个系统通知
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(reachabilityChanged:) name:kReachabilityChangedNotification object:nil];
//初始化
self.internetReachability=[Reachability reachabilityForInternetConnection];
//通知添加到Run Loop
[self.internetReachability startNotifier];
[self updateInterfaceWithReachability:_internetReachability];
return YES;
}

- (void) reachabilityChanged:(NSNotification *)note
{
Reachability* curReach = [note object];
NSParameterAssert([curReach isKindOfClass:[Reachability class]]);
[self updateInterfaceWithReachability:curReach];
}- (void)updateInterfaceWithReachability:(Reachability *)reachability
{
NetworkStatus netStatus = [reachability currentReachabilityStatus];
switch (netStatus) {
case NotReachable:
NSLog(@"====当前网络状态不可达=======http://www.cnblogs.com/xiaofeixiang");
break;
case ReachableViaWiFi:
NSLog(@"====当前网络状态为Wifi=======博客园-Fly_Elephant");
break;
case ReachableViaWWAN:
NSLog(@"====当前网络状态为3G=======keso");
break;
}
}

NSString *remoteHostName = @"www.cnblogs.com/xiaofeixiang";
self.hostReachability = [Reachability reachabilityWithHostName:remoteHostName];