官方Demo下载地址：https://developer.apple.com/library/ios/samplecode/Reachability/Reachability.zip
将Reachability.h 和 Reachability.m 加到自己的项目中，并引用 SystemConfiguration.framework，就可以使用了。
下面代码：
//
// ViewController.m
// 网络状态监测
//
// Created by 王卫亮 on 15/2/4.
// Copyright © 2015年 王卫亮. All rights reserved.
// #import "ViewController.h"
#import "Reachability.h"
#import <ifaddrs.h> @interface ViewController ()
@property (nonatomic, strong)Reachability *conn;
@end @implementation ViewController - (void)viewDidLoad {
[super viewDidLoad]; // 设置网络状态变化时的通知函数
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(networkStateChange) name:kReachabilityChangedNotification object:nil]; self.conn = [Reachability reachabilityForInternetConnection];
[self.conn startNotifier];//开始监测
} -(void)dealloc{
[self.conn stopNotifier];//停止监测
[[NSNotificationCenter defaultCenter] removeObserver:self];
} - (void)networkStateChange{
[self checkNetworkState];
} //检测网络状态
- (void)checkNetworkState{
// 1.检测wifi状态
Reachability *wifi = [Reachability reachabilityForLocalWiFi]; // 2.检测手机是否能上网络(WIFI\3G\2.5G)
Reachability *conn = [Reachability reachabilityForInternetConnection]; // 3.判断网络状态
if ([wifi currentReachabilityStatus] != NotReachable) { // 有wifi
NSLog(@"有wifi");
} else if ([conn currentReachabilityStatus] != NotReachable) { // 没有使用wifi, 使用手机自带网络进行上网
NSLog(@"使用手机自带网络进行上网");
} else { // 没有网络
NSLog(@"没有网络");
}
} //如果只是判断是否有网，可以返回BOOL值 - (BOOL)checkNetwork{
// 1.检测wifi状态
Reachability *wifi = [Reachability reachabilityForLocalWiFi]; // 2.检测手机是否能上网络(WIFI\3G\2.5G)
Reachability *conn = [Reachability reachabilityForInternetConnection]; // 3.判断网络状态
if ([wifi currentReachabilityStatus] != NotReachable || [conn currentReachabilityStatus] != NotReachable) {
return YES;
} else { // 没有网络
return NO;
}
} //需要导入ifadds头文件 //是否连接VPN - (BOOL)isVPNConnected{
struct ifaddrs *interfaces = NULL;
struct ifaddrs *temp_addr = NULL;
int success = ;
//检索当前接口，0 成功
success = getifaddrs(&interfaces);
if (success == ) {
//循环链表接口
temp_addr = interfaces;
while (temp_addr != NULL) {
NSString *string = [NSString stringWithFormat:@"%s" , temp_addr->ifa_name];
if ([string rangeOfString:@"tap"].location != NSNotFound ||
[string rangeOfString:@"tun"].location != NSNotFound ||
[string rangeOfString:@"ppp"].location != NSNotFound){
return YES;
}
temp_addr = temp_addr->ifa_next;
}
}
// Free memory
freeifaddrs(interfaces);
return NO;
} @end
很多公司的项目中都使用了AFNetworking, 或者封装了AFNetworking的YTKNetworking ，AFNetworking封装有Reachability的网络监测，可以直接拿来用
#pragma 监测网络的可链接性
+ (BOOL)netWorkReachabilityWithURLString:(NSString *) strUrl {
__block BOOL netState = NO;
NSURL *baseURL = [NSURL URLWithString:strUrl];
AFHTTPRequestOperationManager *manager = [[AFHTTPRequestOperationManager alloc] initWithBaseURL:baseURL];
NSOperationQueue *operationQueue = manager.operationQueue;
[manager.reachabilityManager setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {
switch (status) {
case AFNetworkReachabilityStatusReachableViaWWAN:
case AFNetworkReachabilityStatusReachableViaWiFi:
[operationQueue setSuspended:NO];
netState = YES;
break;
case AFNetworkReachabilityStatusNotReachable:
netState = NO;
default:
[operationQueue setSuspended:YES];
break;
}
}]; [manager.reachabilityManager startMonitoring];
return netState;
}