Выполняется такой поток.
new Thread(new Runnable() {
@Override
public void run() {
try {
wifi = (WifiManager) getActivity().getApplicationContext().getSystemService(Context.WIFI_SERVICE);
di = wifi.getDhcpInfo();
gateway = IntToStr(di.gateway);
} catch (NullPointerException e) {
e.printStackTrace();
}
gateway_label.post(new Runnable() {
@Override
public void run() {
gateway_label.setText(gateway);
}
});
}
}).start();