public static String getNetworkState(Context context) {
        ConnectivityManager connManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE); // 获取网络服务
        if (null == connManager) { // 为空则认为无网络
            return NETWORK_OTHER;
        }
        // 获取网络类型，如果为空，返回无网络
        NetworkInfo activeNetInfo = connManager.getActiveNetworkInfo();
        if (activeNetInfo == null || !activeNetInfo.isAvailable()) {
            return NETWORK_OTHER;
        }
        // 判断是否为WIFI
        NetworkInfo wifiInfo = connManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
        if (null != wifiInfo) {
            NetworkInfo.State state = wifiInfo.getState();
            if (null != state) {
                if (state == NetworkInfo.State.CONNECTED || state == NetworkInfo.State.CONNECTING) {
                    return NETWORK_WIFI;
                }
            }
        }
        // 若不是WIFI，则去判断是2G、3G、4G网
        TelephonyManager telephonyManager = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
        if (telephonyManager == null) return NETWORK_OTHER;
        int networkType = telephonyManager.getNetworkType();
        switch (networkType) {
            
            // 2G网络
            case TelephonyManager.NETWORK_TYPE_GPRS:
            case TelephonyManager.NETWORK_TYPE_CDMA:
            case TelephonyManager.NETWORK_TYPE_EDGE:
            case TelephonyManager.NETWORK_TYPE_1xRTT:
            case TelephonyManager.NETWORK_TYPE_IDEN:
                return NETWORK_2G;
                // 3G网络
            case TelephonyManager.NETWORK_TYPE_EVDO_A:
            case TelephonyManager.NETWORK_TYPE_UMTS:
            case TelephonyManager.NETWORK_TYPE_EVDO_0:
            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:
                return NETWORK_3G;
            // 4G网络
            case TelephonyManager.NETWORK_TYPE_LTE:
            case 19:// 聚波载合 4G+
                return NETWORK_4G;
            // 5G
// case TelephonyManager.NETWORK_TYPE_NR:// 需要 SdkVersion>=29
            case 20:// 当 SdkVersion<=28 直接写20
                return NETWORK_5G;
            default:
                return NETWORK_OTHER;
        }
    }