问题
Good evening,
I've been trying to achieve something for several days now and I literally don't know what else to try, I've basically tried everything I found online and it still doesn't work but I have the feeling that once I find the solution it must be something quite simple.
I'm working on a bigger project, but here I'm just trying to get a very simple example to work which I can later adapt to my project.
What I want to do
I want to have a counter add +1 every second for 1200 seconds (20 minutes) and write to a file every time it counts. I should end up with a file with 1200 lines with a timestamp per sample.
How I'm trying to do it
I've tried a million things, but here, I've just gone back to a very basic example so I can showcase it and ask for help:
- I have a MAIN acticity with a single START button.
- When clicking the button I start a new process from the activity. This is a FOREGROUND process.
- I start counting in a loop. When I reach 1200, the counting stops.
My problem
While the phone screen is ON everything works just fine, but as soon as I lock the screen and put my phone in my pocket, depending on the phone I'm testing on, it starts to fail.
What I would like
If someone could tell me what to modify / add / change or even do it for me and write back here (it's a really simple project) I would be extremely grateful, I'm wasting a ton of time and I just can't seem to hit the right key.
Code
Since it's a very simple project I will just copy the 4 parts it consists of right here:
XML activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<Button
android:id="@+id/start_button"
android:layout_width="150dp"
android:layout_height="50dp"
android:layout_marginStart="52dp"
android:layout_marginBottom="116dp"
android:onClick="startProcess"
android:text="@string/button_label_start"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toStartOf="parent" />
<TextView
android:id="@+id/counter_textView"
android:layout_width="383dp"
android:layout_height="412dp"
android:gravity="center_horizontal|center_vertical"
android:text="@string/counter_label_value"
android:textSize="160sp"
android:textStyle="bold"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.428"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.169" />
</androidx.constraintlayout.widget.ConstraintLayout>
MANIFEST AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.helloworld">
<uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<service
android:name=".ForegroundService"
android:enabled="true"
android:exported="true"
android:process=":externalProcess">
</service>
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
MAIN MainActivity.java
package com.example.helloworld;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.content.ContextCompat;
import android.app.PendingIntent;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
public static final String CHANNEL_ID = "ForegroundServiceChannel";
private TextView mShowCount;
@Override
protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
super.onActivityResult(requestCode, resultCode, data);
int mCount = data.getIntExtra(ForegroundService.FOREGROUND_MESSAGE, -1);
if(mShowCount != null)
mShowCount.setText(Integer.toString(mCount));
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mShowCount = findViewById(R.id.counter_textView);
}
@Override
protected void onResume() {
super.onResume();
}
@Override
protected void onStart() {
super.onStart();
}
@Override
protected void onPause() {
super.onPause();
}
@Override
protected void onStop() {
super.onStop();
}
@Override
protected void onDestroy() {
super.onDestroy();
}
@Override
protected void onRestart() {
super.onRestart();
}
public void startProcess(View view) {
PendingIntent pendingResult = createPendingResult(100, new Intent(), 0);
Intent serviceIntent = new Intent(this, ForegroundService.class);
serviceIntent.putExtra("pendingIntent", pendingResult);
ContextCompat.startForegroundService(this, serviceIntent);
}
public void stopProcess(View view) {
Intent serviceIntent = new Intent(this, ForegroundService.class);
stopService(serviceIntent);
}
}
FOREGROUND SERVICE ForegroundService.java
package com.example.helloworld;
import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.app.Service;
import android.content.Intent;
import android.os.Build;
import android.os.IBinder;
import android.os.SystemClock;
import android.util.Log;
import androidx.core.app.NotificationCompat;
import java.io.File;
import java.io.FileWriter;
import java.util.Date;
public class ForegroundService extends Service {
public static final String CHANNEL_ID = "ForegroundServiceChannel";
public static final String FOREGROUND_MESSAGE = "com.example.helloworld.FOREGROUND_MESSAGE";
private PendingIntent data;
private int mCount;
private File basePath;
public ForegroundService() {
}
@Override
protected void finalize() throws Throwable {
super.finalize();
}
@Override
public void onCreate() {
super.onCreate();
}
@Override
public boolean stopService(Intent name) {
return super.stopService(name);
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
String input = intent.getStringExtra("inputExtra");
createNotificationChannel();
Intent notificationIntent = new Intent(this, MainActivity.class);
PendingIntent pendingIntent = PendingIntent.getActivity(this,
0, notificationIntent, 0);
Notification notification = new NotificationCompat.Builder(this, MainActivity.CHANNEL_ID)
.setContentTitle("Foreground Service")
.setContentText(input)
.setContentIntent(pendingIntent)
.build();
startForeground(1, notification);
data = intent.getParcelableExtra("pendingIntent");
this.basePath = this.getExternalFilesDir("recs");
mCount = 0;
new Thread(new Runnable() {
public void run() {
try {
while(mCount < 1200) {
Intent resultIntent = new Intent();
resultIntent.putExtra(FOREGROUND_MESSAGE, ++mCount);
writeFile((new Date().getTime() / 1000) + " Increasing counter: " + mCount + "\n");
data.send(ForegroundService.this, 200, resultIntent);
SystemClock.sleep(1000);
}
}catch (Exception ignored){}
}
}).start();
//stopSelf();
return START_NOT_STICKY;
}
private void createNotificationChannel() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
NotificationChannel serviceChannel = new NotificationChannel(
CHANNEL_ID,
"Foreground Service Channel",
NotificationManager.IMPORTANCE_DEFAULT
);
NotificationManager manager = getSystemService(NotificationManager.class);
manager.createNotificationChannel(serviceChannel);
}
}
@Override
public void onDestroy(){
super.onDestroy();
}
@Override
public IBinder onBind(Intent intent) {
return null;
}
private void writeFile(String data)
{
File file = new File (basePath,"test");
if (!file.exists()) {
boolean mkdirs = file.mkdirs();
if (!mkdirs) {
Log.e("RECORDING", "Error creating SAVE BASE PATH");
}
}
try{
File counter_file = new File(file, "counter.txt");
FileWriter writer = new FileWriter(counter_file, true);
writer.append(data);
writer.flush();
writer.close();
} catch (Exception e){
e.printStackTrace();
}
}
}
I know I might be asking a bit too much but I'm quite desperate at this point. I'd be really greatful if someone could come up with a working solution.
Thank you very much.
来源：https://stackoverflow.com/questions/60211491/android-service-not-working-when-phone-is-idle-dozing-locked