How can I implement the Android Car API for Andorid Studio to read out my EVs percentage? - api

Question

I'm currently trying to display the percentage of my Ev Via Android Auto. I can't manage to get CarInfo carInfo = getCarContext().getCarService(CarHardwareManager.class).getCarInfo(); to run. I used this in my automotive build.gradle useLibrary 'android.car' and tried importing many things but that didn't help obviously.
This is my first file:
package com.example.aatest4;
import android.car.Car;
import android.car.CarInfoManager;
import android.content.Intent;
import androidx.annotation.NonNull;
import androidx.car.app.CarAppMetadataHolderService;
import androidx.car.app.CarAppService;
import androidx.car.app.CarContext;
import androidx.car.app.Screen;
import androidx.car.app.Session;
import androidx.car.app.hardware.CarHardwareManager;
import androidx.car.app.hardware.info.CarInfo;
import androidx.car.app.validation.HostValidator;
//import android.content.ServiceConnection;
public class HelloWorldService extends CarAppService {
#NonNull
#Override
public HostValidator createHostValidator() {
return HostValidator.ALLOW_ALL_HOSTS_VALIDATOR;
}
public Session onCreateSession() {
return new Session() {
#NonNull
#Override
public Screen onCreateScreen(#NonNull Intent intent) {
CarInfo carInfo = getCarContext().getCarService(CarHardwareManager.class).getCarInfo();
return new HelloWorldScreen(getCarContext());
}
};
}
}
and this my second:
package com.example.aatest4;
//import android.car.Car;
//import android.car.CarInfoManager;
import androidx.annotation.NonNull;
import androidx.car.app.CarContext;
import androidx.car.app.Screen;
import androidx.car.app.model.Pane;
import androidx.car.app.model.PaneTemplate;
import androidx.car.app.model.Row;
import androidx.car.app.model.Template;
public class HelloWorldScreen extends Screen {
//public HelloWorldScreen() {
public HelloWorldScreen(CarContext carContext) {
super(carContext);
}
#NonNull
#Override
public Template onGetTemplate() {
String akku = String.valueOf(50);
Row row = new Row.Builder().setTitle(akku + "% ").addText(akku + "%").build();
return new PaneTemplate.Builder(new Pane.Builder().addRow(row).build()) .setTitle("Akkuanzeige").build();
//Todo: Center?
}
}