如何检查 android 中的网络强度

        ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo Info = cm.getActiveNetworkInfo();
        if (Info == null || !Info.isConnectedOrConnecting()) {
            Log.i(TAG, "No connection");
        } else {
            int netType = Info.getType();
            int netSubtype = Info.getSubtype();

            if (netType == ConnectivityManager.TYPE_WIFI) {
                Log.i(TAG, "Wifi connection");
                WifiManager wifiManager = (WifiManager) getApplication().getSystemService(Context.WIFI_SERVICE);
                List<ScanResult> scanResult = wifiManager.getScanResults();
                for (int i = 0; i < scanResult.size(); i++) {
                    Log.d("scanResult", "Speed of wifi"+scanResult.get(i).level);//The db level of signal 
                }
                
                
                // Need to get wifi strength
            } else if (netType == ConnectivityManager.TYPE_MOBILE) {
                Log.i(TAG, "GPRS/3G connection");
                // Need to get differentiate between 3G/GPRS
            }
        }