iOS判断网络是否连接

类似于一个网络状况的探针。

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

hostReach = [[Reachability reachabilityWithHostName: @"hubj.cnblogs.com"] retain];

[hostReach startNotifier];

wifiReach=[[Reachability reachabilityForLocalWiFi]retain];

[wifiReach startNotifier];

- (void)reachabilityChanged: (NSNotification* )note {

Reachability* curReach = [note object];

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

NetworkStatus netStatus = [curReach currentReachabilityStatus];

switch (netStatus)

{

case NotReachable:

{

NSLog(@"Access Not Available");

break;

}

case ReachableViaWWAN:

{

NSLog(@"Reachable WWAN");

break;

}

case ReachableViaWiFi:

{

NSLog(@"Reachable WiFi");

break;

}

}

}

判断网络是否连接

/***
* 此函数用来判断是否网络连接服务器正常
* 需要导入Reachability类
*/
+ (BOOL)isExistenceNetwork
{
BOOL isExistenceNetwork;
Reachability *reachability = [Reachability reachabilityWithHostName:@""];  // 测试服务器状态

switch([reachability currentReachabilityStatus]) {
case NotReachable:
isExistenceNetwork = FALSE;
break;
case ReachableViaWWAN:
isExistenceNetwork = TRUE;
break;
case ReachableViaWiFi:
isExistenceNetwork = TRUE;
break;
}
return  isExistenceNetwork;
}

实时通知网络状况

/*
* 在应用委托的方法didFinishLaunchingWithOptions中添加
*/

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(reachabilityChanged:) name:kReachabilityChangedNotification object:nil];
reachability = [[Reachability reachabilityWithHostName:@"www.baidu.com"] retain];
[reachability startNotifier];
........
return YES;

/**
*此函数通过判断联网方式，通知给用户
*/
- (void)reachabilityChanged:(NSNotification *)notification
{
Reachability *curReachability = [notification object];
NSParameterAssert([curReachability isKindOfClass:[Reachability class]]);
NetworkStatus curStatus = [curReachability currentReachabilityStatus];
if(curStatus == NotReachable) {
[DOIN_Util logFax:@"连接失败"];
}
}