判断IOS当前网络类型是2G/3G/4G/WIFI

#import "Reachability.h"
#import 

//Try this
Reachability *reachability = [Reachability reachabilityForInternetConnection];
    [reachability startNotifier];

    NetworkStatus status = [reachability currentReachabilityStatus];

    if(status == NotReachable)
    {
       NSLog(@"none");
        //No internet
    }
    else if (status == ReachableViaWiFi)
    {
        NSLog(@"Wifi");
        //WiFi
    }
    else if (status == ReachableViaWWAN)
    {
        NSLog(@"WWAN");


    //connection type
    CTTelephonyNetworkInfo *netinfo = [[CTTelephonyNetworkInfo alloc] init];
    _carrier = [[netinfo subscriberCellularProvider] carrierName];

    if ([netinfo.currentRadioAccessTechnology isEqualToString:CTRadioAccessTechnologyGPRS]) {
        NSLog(@"2G");
    } else if ([netinfo.currentRadioAccessTechnology isEqualToString:CTRadioAccessTechnologyEdge]) {
        NSLog(@"2G");
    } else if ([netinfo.currentRadioAccessTechnology isEqualToString:CTRadioAccessTechnologyWCDMA]) {
        NSLog(@"3G");
    } else if ([netinfo.currentRadioAccessTechnology isEqualToString:CTRadioAccessTechnologyHSDPA]) {
        NSLog(@"3G");
    } else if ([netinfo.currentRadioAccessTechnology isEqualToString:CTRadioAccessTechnologyHSUPA]) {
        NSLog(@"3G");
    } else if ([netinfo.currentRadioAccessTechnology isEqualToString:CTRadioAccessTechnologyCDMA1x]) {
        NSLog(@"2G");
    } else if ([netinfo.currentRadioAccessTechnology isEqualToString:CTRadioAccessTechnologyCDMAEVDORev0]) {
        NSLog(@"3G");
    } else if ([netinfo.currentRadioAccessTechnology isEqualToString:CTRadioAccessTechnologyCDMAEVDORevA]) {
        NSLog(@"3G");
    } else if ([netinfo.currentRadioAccessTechnology isEqualToString:CTRadioAccessTechnologyCDMAEVDORevB]) {
        NSLog(@"3G");
    } else if ([netinfo.currentRadioAccessTechnology isEqualToString:CTRadioAccessTechnologyeHRPD]) {
        NSLog(@"3G");
    } else if ([netinfo.currentRadioAccessTechnology isEqualToString:CTRadioAccessTechnologyLTE]) {
        NSLog(@"4G");
    }

    }