在使用Kotlin的Android中，您可以使用WifiManager类，它提供有关当前Wi-Fi连接的信息

val wifiManager = applicationContext.getSystemService(Context.WIFI_SERVICE) as WifiManager
if (wifiManager.isWifiEnabled) {
    val wifiInfo = wifiManager.connectionInfo
    val frequency = wifiInfo.frequency
    val is5GHz = frequency in 5_150..5_350 || frequency in 5_470..5_725 || frequency in 5_725..5_825
    val is2_4GHz = frequency in 2_400..2_483

    if (is5GHz) {
        // The network supports 5GHz band
    } else if (is2_4GHz) {
        // The network supports 2.4GHz band
    } else {
        // The network supports both 2.4GHz and 5GHz bands
    }
} else {
    // Wi-Fi is not enabled
}

我们需要使用wifiManager对象的isWifiEnabled（）方法检查设备是否连接到Wi-Fi网络。