需要检查广播接收器上的权限；我需要在拨号时在前台显示应用程序，该应用程序应该始终在手机上运行

if (ContextCompat.checkSelfPermission(this, Manifest.permission.CALL_PHONE) != PackageManager.PERMISSION_GRANTED) {
    ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.CALL_PHONE}, REQUEST_CODE);
}

public class MyForegroundService extends Service {
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Notification notification = new NotificationCompat.Builder(this, CHANNEL_ID)
                .setContentTitle("My App")
                .setContentText("Running in the background")
                .setSmallIcon(R.drawable.ic_notification)
                .build();

        startForeground(1, notification);

        // 执行你的任务

        return START_NOT_STICKY;
    }

    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }
}

<service android:name=".MyForegroundService"
         android:foregroundServiceType="phoneCall" />