// 获取网络类型    public static String getNetworkType(Context context) {        String typeString = "UNKNOW";        NetworkInfo networkInfo = ((ConnectivityManager) context                .getSystemService(Context.CONNECTIVITY_SERVICE)).getActiveNetworkInfo();        if (networkInfo != null && networkInfo.isConnected()) {            if (networkInfo.getType() == ConnectivityManager.TYPE_WIFI) {                typeString = "WIFI";            } else if (networkInfo.getType() == ConnectivityManager.TYPE_MOBILE) {                int networkType = networkInfo.getSubtype();                switch (networkType) {                    case TelephonyManager.NETWORK_TYPE_GPRS:                    case TelephonyManager.NETWORK_TYPE_EDGE:                    case TelephonyManager.NETWORK_TYPE_CDMA:                    case TelephonyManager.NETWORK_TYPE_1xRTT:                    case TelephonyManager.NETWORK_TYPE_IDEN:                        typeString = "2G";                        break;                    case TelephonyManager.NETWORK_TYPE_UMTS:                    case TelephonyManager.NETWORK_TYPE_EVDO_0:                    case TelephonyManager.NETWORK_TYPE_EVDO_A:                    case TelephonyManager.NETWORK_TYPE_HSDPA:                    case TelephonyManager.NETWORK_TYPE_HSUPA:                    case TelephonyManager.NETWORK_TYPE_HSPA:                    case TelephonyManager.NETWORK_TYPE_EVDO_B:                    case TelephonyManager.NETWORK_TYPE_EHRPD:                    case TelephonyManager.NETWORK_TYPE_HSPAP:                        typeString = "3G";                        break;                    case TelephonyManager.NETWORK_TYPE_LTE:                        typeString = "4G";                        break;                    default:                        String typeName = networkInfo.getSubtypeName();                        if (typeName.equalsIgnoreCase("TD-SCDMA")                                || typeName.equalsIgnoreCase("WCDMA")                                || typeName.equalsIgnoreCase("CDMA2000")) {                            typeString = "3G";                        } else {                            typeString = typeName;                        }                        break;                }            }        }        return typeString;    }