21

我正在为大学工作开发 Android 应用程序。在这项工作中，我想创建一个带有计时器的后台服务，当我关闭应用程序时，计时器仍在运行。当我打开应用程序时，我可以看到自启动服务以来的时间。好吧，我的问题是当我关闭应用程序时，后台计时器停止并且不再增加。

你能帮我吗？非常感谢

我的发射器类

    import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends Activity {

    private Button startButton;
    private Button pauseButton;

    private TextView timerValue;

    Intent intent;
    long timeSwapBuff = 0L;
    long updatedTime = 0L;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        timerValue = (TextView) findViewById(R.id.timerValue);

        startButton = (Button) findViewById(R.id.startButton);
        startButton.setOnClickListener(new View.OnClickListener() {

            public void onClick(View view) {
                intent = new Intent(MainActivity.this, CounterService.class);
                startService(intent);
                registerReceiver(broadcastReceiver, new IntentFilter(CounterService.BROADCAST_ACTION));
            }
        });

        pauseButton = (Button) findViewById(R.id.pauseButton);

        pauseButton.setOnClickListener(new View.OnClickListener() {

            public void onClick(View view) {
                unregisterReceiver(broadcastReceiver);
                stopService(intent);
            }
        });

    }

    private BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {

            updateUI(intent);       
        }
    };    

    private void updateUI(Intent intent) {
        int time = intent.getIntExtra("time", 0);

        Log.d("Hello", "Time " + time);

        int mins = time / 60;
        int secs = time % 60;
        timerValue.setText("" + mins + ":"
                + String.format("%02d", secs));
    }


}

在这里，服务类

import android.app.Service;
import android.content.Intent;
import android.os.Handler;
import android.os.IBinder;
import android.os.SystemClock;

public class CounterService  extends Service {

    private Intent intent;
    public static final String BROADCAST_ACTION = "com.javacodegeeks.android.androidtimerexample.MainActivity";

    private Handler handler = new Handler();
    private long initial_time;
    long timeInMilliseconds = 0L;

    @Override
    public void onCreate() {
        super.onCreate();
        initial_time = SystemClock.uptimeMillis();
        intent = new Intent(BROADCAST_ACTION);  
        handler.removeCallbacks(sendUpdatesToUI);
        handler.postDelayed(sendUpdatesToUI, 1000); // 1 second

    }

    private Runnable sendUpdatesToUI = new Runnable() {
        public void run() {
            DisplayLoggingInfo();           
            handler.postDelayed(this, 1000); // 1 seconds
        }
    };    

    private void DisplayLoggingInfo() {

        timeInMilliseconds = SystemClock.uptimeMillis() - initial_time; 

        int timer = (int) timeInMilliseconds / 1000;
        intent.putExtra("time", timer);
        sendBroadcast(intent);

    }

    @Override
    public void onDestroy() {   
        super.onDestroy();
        handler.removeCallbacks(sendUpdatesToUI);   

    }



    @Override
    public IBinder onBind(Intent intent) {
        // TODO Auto-generated method stub
        return null;
    }


}
4

3 回答 3

11

您需要onStop()在活动中的方法中启动服务，如下所示：

@Override
    protected void onStop() {
        super.onStop();
       //write your code here to start your service
    }
于 2013-11-02T11:39:18.917 回答
0

为我工作 

public void onResume() {
    super.onResume();

   //write your code here to start your service

    registerReceiver(broadcastReceiver, new IntentFilter(ServiceClass.BROADCAST_ACTION));
}
于 2016-05-09T16:50:17.120 回答
0

请通过链接希望如果您想在后台运行计时器在后台运行计时器会有所帮助

activity_main.xml

<RelativeLayout android:layout_width="match_parent"
 android:layout_height="match_parent"
 xmlns:android="http://schemas.android.com/apk/res/android">


 <EditText
 android:layout_width="match_parent"
 android:layout_height="wrap_content"
 android:id="@+id/et_hours"
 android:hint="Hours"
 android:inputType="time"
 android:layout_marginRight="5dp"
 />




 <Button
 android:layout_width="match_parent"
 android:layout_height="wrap_content"
 android:id="@+id/btn_timer"
 android:layout_above="@+id/btn_cancel"
 android:text="Start Timer"/>

 <Button
 android:layout_width="match_parent"
 android:layout_height="wrap_content"
 android:layout_alignParentBottom="true"
 android:id="@+id/btn_cancel"
 android:text="cancel timer"/>




 <TextView
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:id="@+id/tv_timer"
 android:layout_centerInParent="true"
 android:textSize="25dp"
 android:textColor="#000000"
 android:text="00:00:00"/>


 </RelativeLayout>

MainActivity.java

package playstore.com.a02backgroundtimer;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.SharedPreferences;
import android.preference.PreferenceManager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

import java.text.SimpleDateFormat;
import java.util.Calendar;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private Button btn_start, btn_cancel;
    private TextView tv_timer;
    String date_time;
    Calendar calendar;
    SimpleDateFormat simpleDateFormat;
    EditText et_hours;

    SharedPreferences mpref;
    SharedPreferences.Editor mEditor;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        init();
        listener();


    }

    private void init() {
        btn_start = (Button) findViewById(R.id.btn_timer);
        tv_timer = (TextView) findViewById(R.id.tv_timer);
        et_hours = (EditText) findViewById(R.id.et_hours);
        btn_cancel = (Button) findViewById(R.id.btn_cancel);



        mpref = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
        mEditor = mpref.edit();

        try {
            String str_value = mpref.getString("data", "");
            if (str_value.matches("")) {
                et_hours.setEnabled(true);
                btn_start.setEnabled(true);
                tv_timer.setText("");

            } else {

                if (mpref.getBoolean("finish", false)) {
                    et_hours.setEnabled(true);
                    btn_start.setEnabled(true);
                    tv_timer.setText("");
                } else {

                    et_hours.setEnabled(false);
                    btn_start.setEnabled(false);
                    tv_timer.setText(str_value);
                }
            }
        } catch (Exception e) {

        }



    }

    private void listener() {
        btn_start.setOnClickListener(this);
        btn_cancel.setOnClickListener(this);

    }

    @Override
    public void onClick(View v) {

        switch (v.getId()) {
            case R.id.btn_timer:


                if (et_hours.getText().toString().length() > 0) {

                    int int_hours = Integer.valueOf(et_hours.getText().toString());

                    if (int_hours<=24) {


                        et_hours.setEnabled(false);
                        btn_start.setEnabled(false);


                        calendar = Calendar.getInstance();
                        simpleDateFormat = new SimpleDateFormat("HH:mm:ss");
                        date_time = simpleDateFormat.format(calendar.getTime());

                        mEditor.putString("data", date_time).commit();
                        mEditor.putString("hours", et_hours.getText().toString()).commit();


                        Intent intent_service = new Intent(getApplicationContext(), Timer_Service.class);
                        startService(intent_service);
                    }else {
                        Toast.makeText(getApplicationContext(),"Please select the value below 24 hours",Toast.LENGTH_SHORT).show();
                    }
/*
                    mTimer = new Timer();
                    mTimer.scheduleAtFixedRate(new TimeDisplayTimerTask(), 5, NOTIFY_INTERVAL);*/
                } else {
                    Toast.makeText(getApplicationContext(), "Please select value", Toast.LENGTH_SHORT).show();
                }
                break;


            case R.id.btn_cancel:


                Intent intent = new Intent(getApplicationContext(),Timer_Service.class);
                stopService(intent);

                mEditor.clear().commit();

                et_hours.setEnabled(true);
                btn_start.setEnabled(true);
                tv_timer.setText("");


                break;

        }

    }

    private BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String str_time = intent.getStringExtra("time");
            tv_timer.setText(str_time);

        }
    };

    @Override
    protected void onResume() {
        super.onResume();
        registerReceiver(broadcastReceiver,new IntentFilter(Timer_Service.str_receiver));

    }

    @Override
    protected void onPause() {
        super.onPause();
        unregisterReceiver(broadcastReceiver);
    }
}

Timer_Service.java

package playstore.com.a02backgroundtimer;

import android.app.Service;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Handler;
import android.os.IBinder;
import android.preference.PreferenceManager;
import android.support.annotation.Nullable;
import android.util.Log;

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.Timer;
import java.util.TimerTask;
import java.util.concurrent.TimeUnit;

public class Timer_Service extends Service {

    public static String str_receiver = "com.countdowntimerservice.receiver";

    private Handler mHandler = new Handler();
    Calendar calendar;
    SimpleDateFormat simpleDateFormat;
    String strDate;
    Date date_current, date_diff;
    SharedPreferences mpref;
    SharedPreferences.Editor mEditor;

    private Timer mTimer = null;
    public static final long NOTIFY_INTERVAL = 1000;
    Intent intent;

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

    @Override
    public void onCreate() {
        super.onCreate();

        mpref = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
        mEditor = mpref.edit();
        calendar = Calendar.getInstance();
        simpleDateFormat = new SimpleDateFormat("HH:mm:ss");

        mTimer = new Timer();
        mTimer.scheduleAtFixedRate(new TimeDisplayTimerTask(), 5, NOTIFY_INTERVAL);
        intent = new Intent(str_receiver);
    }


    class TimeDisplayTimerTask extends TimerTask {

        @Override
        public void run() {
            mHandler.post(new Runnable() {

                @Override
                public void run() {

                    calendar = Calendar.getInstance();
                    simpleDateFormat = new SimpleDateFormat("HH:mm:ss");
                    strDate = simpleDateFormat.format(calendar.getTime());
                    Log.e("strDate", strDate);
                    twoDatesBetweenTime();

                }

            });
        }

    }

    public String twoDatesBetweenTime() {


        try {
            date_current = simpleDateFormat.parse(strDate);
        } catch (Exception e) {

        }

        try {
            date_diff = simpleDateFormat.parse(mpref.getString("data",""));
        } catch (Exception e) {

        }

        try {


            long diff = date_current.getTime() - date_diff.getTime();
            int int_hours = Integer.valueOf(mpref.getString("hours", ""));

            long int_timer = TimeUnit.HOURS.toMillis(int_hours);
            long long_hours = int_timer - diff;
            long diffSeconds2 = long_hours / 1000 % 60;
            long diffMinutes2 = long_hours / (60 * 1000) % 60;
            long diffHours2 = long_hours / (60 * 60 * 1000) % 24;


            if (long_hours > 0) {
                String str_testing = diffHours2 + ":" + diffMinutes2 + ":" + diffSeconds2;

                Log.e("TIME", str_testing);

                fn_update(str_testing);
            } else {
                mEditor.putBoolean("finish", true).commit();
                mTimer.cancel();
            }
        } catch (Exception e) {
            mTimer.cancel();
            mTimer.purge();


        }

        return "";

    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        Log.e("Service finish", "Finish");
    }

    private void fn_update(String str_time) {

        intent.putExtra("time", str_time);
        sendBroadcast(intent);
    }
}

一旦应用程序启动，您需要提及您想要计时器的小时数......然后在重新启动应用程序时杀死应用程序后，它将显示计时器的开始时间......现在您可以根据您的要求自定义应用程序。

于 2019-01-31T14:16:46.317 回答