你可以在Github下载这个Demo https://github.com/JanzTam/Reachability_Demo
首先，引入系统的Reachability类，不知道怎么引入的话，在Xcode，按下shift+command+0，搜索Reachability，看到图中所选的工程下载即可。
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Reachability.png
并导入相关.h文件
#import<CoreTelephony/CTTelephonyNetworkInfo.h>
引入后，Reachability.h文件里面修改NetworkStatus的枚举，
typedef enum : NSInteger { NotReachable = 0, ReachableViaWiFi, ReachableViaWWAN, kReachableVia2G, kReachableVia3G, kReachableVia4G} NetworkStatus;
在修改下Reachability.m文件
找到
- (NetworkStatus)networkStatusForFlags:(SCNetworkReachabilityFlags)flags
修改下面的代码
if ((flags & kSCNetworkReachabilityFlagsIsWWAN) == kSCNetworkReachabilityFlagsIsWWAN) {if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 7.0) { CTTelephonyNetworkInfo * info = [[CTTelephonyNetworkInfo alloc] init]; NSString *currentRadioAccessTechnology = info.currentRadioAccessTechnology; if (currentRadioAccessTechnology) { if ([currentRadioAccessTechnology isEqualToString:CTRadioAccessTechnologyLTE]) { returnValue = kReachableVia4G; } else if ([currentRadioAccessTechnology isEqualToString:CTRadioAccessTechnologyEdge] || [currentRadioAccessTechnology isEqualToString:CTRadioAccessTechnologyGPRS]) { returnValue = kReachableVia2G; } else { returnValue = kReachableVia3G; } return returnValue; } } if ((flags & kSCNetworkReachabilityFlagsTransientConnection) == kSCNetworkReachabilityFlagsTransientConnection) { if((flags & kSCNetworkReachabilityFlagsConnectionRequired) == kSCNetworkReachabilityFlagsConnectionRequired) { returnValue = kReachableVia2G; return returnValue; } returnValue = kReachableVia3G; return returnValue; } returnValue = ReachableViaWWAN; }
在AppDelegate里加入
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions{ //设置状态栏 [[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleDefault]; // 监测网络情况 [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(reachabilityChanged:) name: kReachabilityChangedNotification object: nil]; hostReach = [Reachability reachabilityWithHostName:@"www.baidu.com"]; [hostReach startNotifier];}
- (void)reachabilityChanged:(NSNotification *)note{ Reachability* curReach = [note object]; NSParameterAssert([curReach isKindOfClass: [Reachability class]]); NetworkStatus status = [curReach currentReachabilityStatus]; switch (status) { case NotReachable: break; case ReachableViaWiFi: case ReachableViaWWAN: break; case kReachableVia2G: break; case kReachableVia3G: break; case kReachableVia4G: break; }}
原标题：iOS网络检测Reachability 使用 Demo，可检测2、3、4G
关键词：IOS
我知道了 