iOS监测网络状态框架 Reachability

#import "Reachability.h"

(1)使用同步的方式是比较简单,通过代码检查网络：

Reachability *reach = [Reachability reachabilityForInternetConnection];

NetworkStatus status = [reach currentReachabilityStatus];

(2)通过检查某个主机能否访问来判断当前网络是否可用：

Reachability *reach = [Reachability reachabilityWithHostName:@“www.baidu.com”];

NetworkStatus status = [reach currentReachabilityStatus];  

ReachableViaWWAN  3G 网络

ReachableViaWiFi   WiFi网络

NotReachable  无网络

（3）实时监测网络状态

@property(nonatomic,strong)Reachability*reachability;

- (BOOL)application:(UIApplication*)application didFinishLaunchingWithOptions:(NSDictionary*)launchOptions {

[[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(netStatusChanged:)name:kReachabilityChangedNotification object:nil];

self.reachability= [ReachabilityreachabilityWithHostName:@"www.baidu.com"];

[self.reachability startNotifier];

}

-(void)netStatusChanged:(NSNotification*)notification{

Reachability*currentStatus = [notificationobject];

NSParameterAssert([currentStatus isKindOfClass:[Reachability class]]);

NetworkStatus status = [currentStatus currentReachabilityStatus];

if(status==NotReachable) {

UIAlertView*alert = [[UIAlertView alloc]initWithTitle:@"温馨提示"message:@"网络不可用"delegate:nil cancelButtonTitle:@"确定"otherButtonTitles:nil];

[alert show];

return;

}

}