service使用范例一则

service使用范例一则：

/* * Copyright (C) 2010 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * *      http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */package com.newalarm;import android.app.Activity;import android.app.AlarmManager;import android.app.PendingIntent;import android.content.Intent;import android.os.Bundle;import android.os.SystemClock;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.CompoundButton;import android.widget.Toast;/** * This is the activity that controls AlarmService. * <p> * When the user clicks the "Start Alarm Service" button, it triggers a * repeating countdown timer. Every thirty seconds, the timer starts * AlarmService, which then runs for 15 seconds and shuts itself down. * </p> * <p> * When the user clicks the "Stop Alarm Service" button, it stops the countdown * timer. * </p> */public class AlarmActivity extends Activity {    // 30 seconds in milliseconds    private static final long THIRTY_SECONDS_MILLIS = 30 * 1000;    // An intent for AlarmService, to trigger it as if the Activity called    // startService().    private PendingIntent mAlarmSender;    // Contains a handle to the system alarm service    private AlarmManager mAlarmManager;    CompoundButton c;    /**     * This method is called when Android starts the activity. It initializes     * the UI.     * <p>     * This method is automatically called when Android starts the Activity     * </p>     */    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        // Create a PendingIntent to trigger a startService() for AlarmService        mAlarmSender = PendingIntent.getService( // set up an intent for a call                // to a service                AlarmActivity.this, // the current context                0, // request code (not used)                new Intent(AlarmActivity.this, AlarmService.class), // A new                // Service                // intent                0 // flags (none are required for a service)                );        // Creates the main view        setContentView(R.layout.main);        // Finds the button that starts the repeating countdown timer        Button button = (Button) findViewById(R.id.start_alarm);        // Sets the listener for the start button        button.setOnClickListener(mStartAlarmListener);        // Finds the buttodon that stops countwn timer        button = (Button) findViewById(R.id.stop_alarm);        // Sets the listener for the stop button        button.setOnClickListener(mStopAlarmListener);        // Gets the handle to the system alarm service        mAlarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);    }    // Creates a new anonymous click listener for the start button. It starts    // the repeating    // countdown timer.    private OnClickListener mStartAlarmListener = new OnClickListener() {        // Sets the callback for when the button is clicked        public void onClick(View v) {            // Sets the time when the alarm will first go off            // The Android AlarmManager uses this form of the current time.            long firstAlarmTime = SystemClock.elapsedRealtime();            // Sets a repeating countdown timer that triggers AlarmService            mAlarmManager.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP, // based                    // on                    // time                    // since                    // last                    // wake                    // up                    firstAlarmTime, // sends the first alarm immediately                    THIRTY_SECONDS_MILLIS, // repeats every thirty seconds                    mAlarmSender // when the alarm goes off, sends this Intent                    );            // Notifies the user that the repeating countdown timer has been            // started            Toast.makeText(AlarmActivity.this, // the current context                    R.string.repeating_started, // the message to display                    Toast.LENGTH_LONG // how long to display the message                    ).show(); // show the message on the screen        }    };    // Creates a new anonymous click listener for the stop button. It shuts off    // the repeating    // countdown timer.    private OnClickListener mStopAlarmListener = new OnClickListener() {        // Sets the callback for when the button is clicked        public void onClick(View v) {            // Cancels the repeating countdown timer            mAlarmManager.cancel(mAlarmSender);            // Notifies the user that the repeating countdown timer has been            // stopped            Toast.makeText(AlarmActivity.this, // the current context                    R.string.repeating_stopped, // the message to display                    Toast.LENGTH_LONG // how long to display the message                    ).show(); // display the message        }    };}

 

 

/* * Copyright (C) 2010 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * *      http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */package com.newalarm;import android.app.Notification;import android.app.NotificationManager;import android.app.PendingIntent;import android.app.Service;import android.content.Intent;import android.os.Binder;import android.os.IBinder;import android.os.Parcel;import android.os.RemoteException;import android.widget.Toast;/** * <p> * This class implements a service. The service is started by AlarmActivity, which contains a * repeating countdown timer that sends a PendingIntent. The user starts and stops the timer with * buttons in the UI. * </p> * <p> * When this service is started, it creates a Runnable and starts it in a new Thread. The * Runnable does a synchronized lock on the service's Binder object for 15 seconds, then issues * a stopSelf(). The net effect is a new worker thread that takes 15 seconds to run and then * shuts down the entire service. The activity restarts the service after 15 more seconds, when the * countdown timer triggers again. * </p> * <p> * This service is provided as the service under test for the sample test application * AlarmServiceTest. * </p> * <p> * Note: Since this sample is based on the Android 1.5 platform, it does not implement * onStartCommand. See the Javadoc for android.app.Service for more details. * </p> */public class AlarmService extends Service {    // Defines a label for the thread that this service starts    private static final String ALARM_SERVICE_THREAD = "AlarmService";    // Defines 15 seconds    public static final long WAIT_TIME_SECONDS = 15;    // Define the number of milliseconds in one second    public static final long MILLISECS_PER_SEC = 1000;    /*     * For testing purposes, the following variables are defined as fields and set to     * package visibility.     */    // The NotificationManager used to send notifications to the status bar.    NotificationManager mNotificationManager;    // An Intent that displays the client if the user clicks the notification.    PendingIntent mContentIntent;    // A Notification to send to the Notification Manager when the service is started.    Notification mNotification;    // A Binder, used as the lock object for the worker thread.    IBinder mBinder = new AlarmBinder();    // A Thread object that will run the background task    Thread mWorkThread;    // The Runnable that is the service's "task". This illustrates how a service is used to    // offload work from a client.    Runnable mWorkTask = new Runnable() {        public void run() {            // Sets the wait time to 15 seconds, simulating a 15-second background task.            long waitTime = System.currentTimeMillis() + WAIT_TIME_SECONDS * MILLISECS_PER_SEC;            // Puts the wait in a while loop to ensure that it actually waited 15 seconds.            // This covers the situation where an interrupt might have overridden the wait.            while (System.currentTimeMillis() < waitTime) {                // Waits for 15 seconds or interruption                synchronized (mBinder) {                    try {                        // Waits for 15 seconds or until an interrupt triggers an exception.                        // If an interrupt occurs, the wait is recalculated to ensure a net                        // wait of 15 seconds.                        mBinder.wait(waitTime - System.currentTimeMillis());                    } catch (InterruptedException e) {                    }                }            }            // Stops the current service. In response, Android calls onDestroy().            stopSelf();        }    };    /**     *  Makes a full concrete subclass of Binder, rather than doing it in line, for readability.     */    public class AlarmBinder extends Binder {        // Constructor. Calls the super constructor to set up the instance.        public AlarmBinder() {            super();        }        @Override        protected boolean onTransact(int code, Parcel data, Parcel reply, int flags)            throws RemoteException {            // Call the parent method with the arguments passed in            return super.onTransact(code, data, reply, flags);        }    }    /**     * Initializes the service when it is first started by a call to startService() or     * bindService().     */    @Override    public void onCreate() {        // Gets a handle to the system mNotification service.        mNotificationManager = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);        // Updates the status bar to indicate that this service is running.        showNotification();        // Creates a new thread. A new thread is used so that the service's work doesn't block        // anything on the calling client's thread. By default, a service runs in the same        // process and thread as the client that starts it.        mWorkThread = new Thread(            null,  // threadgroup (in this case, null)            mWorkTask, // the Runnable that will run in this thread            ALARM_SERVICE_THREAD        );        // Starts the thread        mWorkThread.start();    }    /**     * Stops the service in response to the stopSelf() issued when the wait is over. Other     * clients that use this service could stop it by issuing a stopService() or a stopSelf() on     * the service object.     */    @Override    public void onDestroy() {        // Cancels the status bar mNotification based on its ID, which is set in showNotification().        mNotificationManager.cancel(R.string.alarm_service_started);        // Sends a notification to the screen.        Toast.makeText(            this,  // the current context            R.string.alarm_service_finished,  // the message to show            Toast.LENGTH_LONG   // how long to keep the message on the screen        ).show();  // show the text    }    // Returns the service's binder object to clients that issue onBind().    @Override    public IBinder onBind(Intent intent) {        return mBinder;    }    /**     * Displays a notification in the status bar that this service is running. This method     * also creates an Intent for the AlarmActivity client and attaches it to the notification     * line. If the user clicks the line in the expanded status window, the Intent triggers     * AlarmActivity.     */    private void showNotification() {        // Sets the text to use for the status bar and status list views.        CharSequence notificationText = getText(R.string.alarm_service_started);        // Sets the icon, status bar text, and display time for the mNotification.        mNotification = new Notification(            R.drawable.stat_sample,  // the status icon            notificationText, // the status text            System.currentTimeMillis()  // the time stamp        );        // Sets up the Intent that starts AlarmActivity        mContentIntent = PendingIntent.getActivity(            this,  // Start the Activity in the current context            0,   // not used            new Intent(this, AlarmActivity.class),  // A new Intent for AlarmActivity            0  // Use an existing activity instance if available        );        // Creates a new content view for the mNotification. The view appears when the user        // shows the expanded status window.        mNotification.setLatestEventInfo(            this,  //  Put the content view in the current context            getText(R.string.alarm_service_label),  // The text to use as the label of the entry            notificationText,  // The text to use as the contents of the entry            mContentIntent  // The intent to send when the entry is clicked        );        // Sets a unique ID for the notification and sends it to NotificationManager to be        // displayed. The ID is the integer marker for the notification string, which is        // guaranteed to be unique within the entire application.        mNotificationManager.notify(            R.string.alarm_service_started,  // unique id for the mNotification            mNotification   // the mNotification object        );    }}