要获取当前网络状态（Wi-Fi、4G、3G）

+ (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;
}

每一项是什么意思不太清楚，但是有时候要用区分2G、3G、4G和wifi

/*
             NSArray *typeStrings2G = @[CTRadioAccessTechnologyEdge,
             CTRadioAccessTechnologyGPRS,
             CTRadioAccessTechnologyCDMA1x];
             
             NSArray *typeStrings3G = @[CTRadioAccessTechnologyHSDPA,
             CTRadioAccessTechnologyWCDMA,
             CTRadioAccessTechnologyHSUPA,
             CTRadioAccessTechnologyCDMAEVDORev0,
             CTRadioAccessTechnologyCDMAEVDORevA,
             CTRadioAccessTechnologyCDMAEVDORevB,
             CTRadioAccessTechnologyeHRPD];
             
             NSArray *typeStrings4G = @[CTRadioAccessTechnologyLTE];
             */