在工程添加：SystemConfiguration.framework
去苹果API里搜索Reachability，下载Demo(点击左上角Download Sample Code 即可下载)，把demo里的Reachability.h和Reachability.m拖到自己的工程里。也可以在百度里面搜索”Reachability”，然后下载，不一定非要到苹果官网去下载。
但是使用Reachability有一个问题，就是它只能判断当前是Wifi或者手机自带网络，没有办法详细得判断2G、3G、4G。
如果确定为手机自带网络，这时可以使用系统自带的API来判断是2G、3G还是4G，这就要使用到CTTelephonyNetworkInfo这类，记得在工程添加CoreTelephony.framework
记得导入头文件：
import "Reachability.h"
import <CoreTelephony/CTCarrier.h>
import <CoreTelephony/CTTelephonyNetworkInfo.h>
#if (CC_TARGET_PLATFORM == CC_PLATFORM_IOS)
#import "Reachability.h"
#include <sys/param.h>
#include <sys/mount.h>
#endif
下面附上我在项目中使用的代码：
+ (NSString *)getNetconnType{
NSString *netconnType = @"";
Reachability *reach = [Reachability reachabilityWithHostName:@"www.apple.com"];
switch ([reach currentReachabilityStatus]) {
case NotReachable:// 没有网络
{
netconnType = @"no network";
}
break;
case ReachableViaWiFi:// Wifi
{
netconnType = @"Wifi";
}
break;
case ReachableViaWWAN:// 手机自带网络
{
// 获取手机网络类型
CTTelephonyNetworkInfo *info = [[CTTelephonyNetworkInfo alloc] init];
NSString *currentStatus = info.currentRadioAccessTechnology;
if ([currentStatus isEqualToString:@"CTRadioAccessTechnologyGPRS"]) {
netconnType = @"GPRS";
}else if ([currentStatus isEqualToString:@"CTRadioAccessTechnologyEdge"]) {
netconnType = @"2.75G EDGE";
}else if ([currentStatus isEqualToString:@"CTRadioAccessTechnologyWCDMA"]){
netconnType = @"3G";
}else if ([currentStatus isEqualToString:@"CTRadioAccessTechnologyHSDPA"]){
netconnType = @"3.5G HSDPA";
}else if ([currentStatus isEqualToString:@"CTRadioAccessTechnologyHSUPA"]){
netconnType = @"3.5G HSUPA";
}else if ([currentStatus isEqualToString:@"CTRadioAccessTechnologyCDMA1x"]){
netconnType = @"2G";
}else if ([currentStatus isEqualToString:@"CTRadioAccessTechnologyCDMAEVDORev0"]){
netconnType = @"3G";
}else if ([currentStatus isEqualToString:@"CTRadioAccessTechnologyCDMAEVDORevA"]){
netconnType = @"3G";
}else if ([currentStatus isEqualToString:@"CTRadioAccessTechnologyCDMAEVDORevB"]){
netconnType = @"3G";
}else if ([currentStatus isEqualToString:@"CTRadioAccessTechnologyeHRPD"]){
netconnType = @"HRPD";
}else if ([currentStatus isEqualToString:@"CTRadioAccessTechnologyLTE"]){
netconnType = @"4G";
}
}
break;
default:
break;
}
return netconnType;
}