Android 电池电量监控初步

整体思路概览

①由于要显示电池图标，因此需要一组对应的小icon，程序算出当前电量之后，就在状态栏上显示对应的icon即可。本程序用到的icon已经提供在附件，下载后将里面的icons直接复制到res\drawable-hdpi中即可。

②由于电池更新是一个长期存在的过程，因此需要将我们的程序注册为系统服务，以便长期生存于Android系统中。

③服务不会自行启动，因此我们需要为自己的服务创建一个Activity，在第一次启动本程序的Activity时创建并启动我们的监控服务，之后的事便交由服务处理，Activity暂时未有太大作用（之后还可以在Activity中显示电池当前的各种基本属性等等，本文不作介绍），当然，我们也可以不要Activity，直接将我们的服务设置为开机启动即可，关于开机启动的事项已在【Android开机启动Activity或Service的方法】一文中详细描述，恕不赘述。

④为了方便起见，应该制作本程序的桌面小工具，也就用到了AppWidget方面的知识，稍后一一道来。

分而治之

小麻雀的心脏——电池监控服务MonitorService

ACTION_BATTERY_CHANGED    的完整代码，我会在可能费解的地方批注，希望能帮助大家理解。  

查看源码 打印 ?

001	package com.billhoo.study;

002

003	import android.app.Notification;  //通知，即显示在屏幕左上角的小图标

004	import android.app.NotificationManager;

005	import android.app.PendingIntent;

006	import android.app.Service;

007	import android.content.BroadcastReceiver;

008	import android.content.Context;

009	import android.content.Intent;

010	import android.content.IntentFilter;

011	import android.os.BatteryManager;

012	import android.os.IBinder;

013

014	public class MonitorService extends Service {

015

@Override

016	public IBinder onBind(Intent intent) {

017	return null;

018

}

019

020

@Override

021	public void onStart(Intent intent, int startId) {

022	// 定义电池电量更新广播的过滤器,只接受带有ACTION_BATTERRY_CHANGED事件的Intent

023	IntentFilter batteryChangedReceiverFilter = new IntentFilter();

024	batteryChangedReceiverFilter.addAction(Intent.ACTION_BATTERY_CHANGED);

025

026	// 向系统注册batteryChangedReceiver接收器，本接收器的实现见代码字段处

027	registerReceiver(batteryChangedReceiver, batteryChangedReceiverFilter);

028

029	// 实例化Notification通知的管理器，即字段notification manager

030	notifyManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);

031

032	// 由于初始化本服务时系统可能没有发出ACTION_BATTERY_CHANGED广播，那么刚才注册的那个接收器将不会在本服务启动时被激活，这种情况下就无法显示当前电量，因此在这里添加一个匿名广播接收器。

033	new BroadcastReceiver() {

034

@Override

035	public void onReceive(Context context, Intent intent) {

036	int level = intent.getIntExtra("level", 0);  //电池电量等级

037	int scale = intent.getIntExtra("scale", 100);  //电池满时百分比

038	int status = intent.getIntExtra("status", 0);  //电池状态

039

040

// 若正在充电

041	if (status == BatteryManager.BATTERY_STATUS_CHARGING)

042	notification = getNotification(getChargingIcon(level * 100 / scale),

043	"电池监控", System.currentTimeMillis(), "电池电量", "正在充电");

044

else

045	notification = getNotification(getStateIcon(level * 100 / scale),

046	"电池监控", System.currentTimeMillis(), "电池电量", "请及时充电");

047

048	//向系统发送此通知，为方便起见，通知ID简单设为0

049	notifyManager.notify(0, notification);

050

}

051

};

052

}

053

054

@Override

055	public void onDestroy() {

056	//当本服务终止时，通过通知ID注销左上角的通知

057	notifyManager.cancel(0);

058

}

059

060	// --------------------------------------私有方法------------------------------

061	// 获得一个notification

062	private Notification getNotification(int notificationIcon, String tickerText,

063	long when, String contentTitle, String contentText) {

064	// 定义该notification的扩展文本和intent

065	Notification notification = new Notification(notificationIcon, tickerText,

066

when);

067	Context context = getApplicationContext();

068	Intent notificationIntent = new Intent(context, BatteryInfo.class);

069	PendingIntent contentIntent = PendingIntent.getActivity(this, 0,

070	notificationIntent, 0);

071	notification.setLatestEventInfo(context, contentTitle, contentText,

072	contentIntent);

073

074	// 设置本状态出现在“正在进行”而非“通知”栏目，不允许用户清除状态图标

075	notification.flags |= Notification.FLAG_ONGOING_EVENT;

076	return notification;

077

}

078

079	// 获得对应的电池状态图标

080	private int getStateIcon(int batteryHealth) {

081	if (batteryHealth >= 0 || batteryHealth <= 100)

082	return batteryStateIcons[batteryHealth]; //这里是为了方便起见而硬编码的资源数组，直接从R.java文件中提取的十六进制资源ID

083	return R.drawable.stat_sys_battery_unknown;

084

}

085

086	// 获得对应的充电状态图标

087	private int getChargingIcon(int batteryHealth) {

088	if (batteryHealth >= 0 && batteryHealth < 5)

089	return R.drawable.stat_sys_battery_charge_anim0;

090	if (batteryHealth >= 5 && batteryHealth < 10)

091	return R.drawable.stat_sys_battery_charge_anim01;

092	if (batteryHealth >= 10 && batteryHealth < 15)

093	return R.drawable.stat_sys_battery_charge_anim02;

094	if (batteryHealth >= 15 && batteryHealth < 20)

095	return R.drawable.stat_sys_battery_charge_anim03;

096	if (batteryHealth >= 20 && batteryHealth < 25)

097	return R.drawable.stat_sys_battery_charge_anim04;

098	if (batteryHealth >= 25 && batteryHealth < 30)

099	return R.drawable.stat_sys_battery_charge_anim05;

100	if (batteryHealth >= 30 && batteryHealth < 35)

101	return R.drawable.stat_sys_battery_charge_anim06;

102	if (batteryHealth >= 35 && batteryHealth < 40)

103	return R.drawable.stat_sys_battery_charge_anim07;

104	if (batteryHealth >= 40 && batteryHealth < 45)

105	return R.drawable.stat_sys_battery_charge_anim08;

106	if (batteryHealth >= 45 && batteryHealth < 50)

107	return R.drawable.stat_sys_battery_charge_anim09;

108	if (batteryHealth >= 50 && batteryHealth < 55)

109	return R.drawable.stat_sys_battery_charge_anim10;

110	if (batteryHealth >= 55 && batteryHealth < 60)

111	return R.drawable.stat_sys_battery_charge_anim11;

112	if (batteryHealth >= 60 && batteryHealth < 65)

113	return R.drawable.stat_sys_battery_charge_anim12;

114	if (batteryHealth >= 65 && batteryHealth < 70)

115	return R.drawable.stat_sys_battery_charge_anim13;

116	if (batteryHealth >= 70 && batteryHealth < 75)

117	return R.drawable.stat_sys_battery_charge_anim14;

118	if (batteryHealth >= 75 && batteryHealth < 80)

119	return R.drawable.stat_sys_battery_charge_anim15;

120	if (batteryHealth >= 80 && batteryHealth < 85)

121	return R.drawable.stat_sys_battery_charge_anim16;

122	if (batteryHealth >= 85 && batteryHealth < 90)

123	return R.drawable.stat_sys_battery_charge_anim17;

124	if (batteryHealth >= 90 && batteryHealth < 95)

125	return R.drawable.stat_sys_battery_charge_anim18;

126	if (batteryHealth >= 95 && batteryHealth < 100)

127	return R.drawable.stat_sys_battery_charge_anim19;

128	if (batteryHealth == 100)

129	return R.drawable.stat_sys_battery_charge_animfull;

130	return R.drawable.stat_sys_battery_unknown;

131

}

132

133	// -------------------------------私有字段--------------------------------------

134	private NotificationManager notifyManager = null;

135	private Notification notification = null;

136

137	//这里是为了方便起见而硬编码的icon资源数组，直接从R.java文件中提取的十六进制资源ID，本数组的0号元素0x7f020002表示资源stat_sys_battery_0.png（见附件），以后累加。不同配置的ID可能不同，请读者自行修改。

138	private int batteryStateIcons[] = { 0x7f020002, 0x7f020003, 0x7f020004,

139	0x7f020005, 0x7f020006, 0x7f020007, 0x7f020008, 0x7f020009, 0x7f02000a,

140	0x7f02000b, 0x7f02000c, 0x7f02000d, 0x7f02000e, 0x7f02000f, 0x7f020010,

141	0x7f020011, 0x7f020012, 0x7f020013, 0x7f020014, 0x7f020015, 0x7f020016,

142	0x7f020017, 0x7f020018, 0x7f020019, 0x7f02001a, 0x7f02001b, 0x7f02001c,

143	0x7f02001d, 0x7f02001e, 0x7f02001f, 0x7f020020, 0x7f020021, 0x7f020022,

144	0x7f020023, 0x7f020024, 0x7f020025, 0x7f020026, 0x7f020027, 0x7f020028,

145	0x7f020029, 0x7f02002a, 0x7f02002b, 0x7f02002c, 0x7f02002d, 0x7f02002e,

146	0x7f02002f, 0x7f020030, 0x7f020031, 0x7f020032, 0x7f020033, 0x7f020034,

147	0x7f020035, 0x7f020036, 0x7f020037, 0x7f020038, 0x7f020039, 0x7f02003a,

148	0x7f02003b, 0x7f02003c, 0x7f02003d, 0x7f02003e, 0x7f02003f, 0x7f020040,

149	0x7f020041, 0x7f020042, 0x7f020043, 0x7f020044, 0x7f020045, 0x7f020046,

150	0x7f020047, 0x7f020048, 0x7f020049, 0x7f02004a, 0x7f02004b, 0x7f02004c,

151	0x7f02004d, 0x7f02004e, 0x7f02004f, 0x7f020050, 0x7f020051, 0x7f020052,

152	0x7f020053, 0x7f020054, 0x7f020055, 0x7f020056, 0x7f020057, 0x7f020058,

153	0x7f020059, 0x7f02005a, 0x7f02005b, 0x7f02005c, 0x7f02005d, 0x7f02005e,

154	0x7f02005f, 0x7f020060, 0x7f020061, 0x7f020062, 0x7f020063, 0x7f020064,

155	0x7f020065, 0x7f02007b };

156

157	// 接受电池信息更新的广播

158	private BroadcastReceiver batteryChangedReceiver = new BroadcastReceiver() {

159	public void onReceive(Context context, Intent intent) {

160	int level = intent.getIntExtra("level", 0);

161	int scale = intent.getIntExtra("scale", 100);

162	int status = intent.getIntExtra("status", 0);

163

164

// 若正在充电

165	if (status == BatteryManager.BATTERY_STATUS_CHARGING)

166	notification = getNotification(getChargingIcon(level * 100 / scale),

167	"Battery Monitor", System.currentTimeMillis(), "电池电量", "正在充电");

168

else

169	notification = getNotification(getStateIcon(level * 100 / scale),

170	"Battery Monitor", System.currentTimeMillis(), "电池电量", "请及时充电");

171	notifyManager.notify(0, notification);

172

}

173

};

174

}

光有心，不跳怎么行？——BatteryMonitor

服务在系统配置文件中进行注册。

查看源码 打印 ?

1

2	<service android:name=".MonitorService" android:enabled="true" />

Bill的另一篇文章【Android开机启动Activity或Service的方法】），下面，我们将在一个Activity中启动MonitorService服务。    在AndroidManifest.xml中进行注册  

查看源码 打印 ?

1

2	<activity android:name=".BatteryMonitor" android:label="@string/battery_monitor_name">

3	<intent-filter>

4	<action android:name="android.intent.action.MAIN" />

5	<category android:name="android.intent.category.LAUNCHER" />

6	intent-filter>

7

activity>

中编码启动我们的MonitorService服务即可  

查看源码 打印 ?

01	package com.billhoo.study;

02

03	import android.app.Activity;

04	import android.content.Intent;

05	import android.os.Bundle;

06

07

08	public class BatteryMonitor extends Activity {

09	/** Called when the activity is first created. */

10

@Override

11	public void onCreate(Bundle savedInstanceState) {

12	super.onCreate(savedInstanceState);

13	setContentView(R.layout.main);

14

15	//启动电池监控服务

16	startService(new Intent(this, MonitorService.class));

17

}

18

}

，看看左上角是不是出现了一个小电池图标，并显示着当前电量？ 麻雀虽小，五脏俱全——MonitorWidgetProvider   ，为麻雀穿上衣服    用户会将自己喜爱的小程序放在桌面以便快速启动，当然我们就不能放过这个机会！    还做不到这一点，难道我们应该期望用户在他的程序列表中长按我们的Activity，然后使出吃奶的劲儿把它扔在桌面上吗？不，他们通常长按桌面，然后轻点一个自己中意的Widget插件便能满足他们的需求。    ，一来方便用户查看电池状态（仅凭左上角的通知有时候并不能满足用户的需求），二来方便用户随时启动本程序附带的电池详细数据报告（本功能并未在本文中实现）。    本身就是一个广播接收器（BroadcastReceiver），因此我们最初企图直接用这个Widget接受ACTION_BATTERY_CHANGED广播并作出反应，但却发现这个接收器并不会接受电池更新的广播（不论我们在配置文件中配置与否）。所以只能另寻出路，我们想到，可以使用一个单独的为本Widget服务的Service，该Service检测到电池电量更新后就更新桌面的Widget显示。于是便有以下Widget及其配套Service的实现。    创建一个配置文件，用于描述本Widget在桌面显示时是个什么样子。  

查看源码 打印 ?

01

02	xml version="1.0" encoding="utf-8"?>

03	<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

04	android:orientation="vertical"

05	android:layout_width="72dip"

06	android:layout_height="72dip">

07	<ImageView android:id="@+id/monitor_widget_view"

08	android:layout_width="fill_parent"

09	android:layout_height="fill_parent"

10

11	android:src="@drawable/vertical_battery_unknown" />

12	LinearLayout>

查看源码 打印 ?

1

2	xml version="1.0" encoding="utf-8"?>

3	<appwidget-providerxmlns:androidappwidget-providerxmlns:android="http://schemas.android.com/apk/res/android"               android:initialLayout="@layout/monitor_widget_layout"

4	android:minWidth="72dip" android:minHeight="72dip" />

配置文件中注册我们的Widget  

查看源码 打印 ?

1	<receiver android:name=".MonitorWidgetProvider">

2	<intent-filter>

3	<action android:name="android.appwidget.action.APPWIDGET_UPDATE" />

4	<action android:name="android.intent.action.BATTERY_CHANGED" />

5	intent-filter>

6	<meta-data android:name="android.appwidget.provider"

7	android:resource="@xml/monitor_widget_info" />

8

receiver>

的实现代码

查看源码 打印 ?

01	package com.billhoo.study;

02

03	import android.appwidget.AppWidgetManager;

04	import android.appwidget.AppWidgetProvider;

05	import android.content.Context;

06	import android.content.Intent;

07

08	public class MonitorWidgetProvider extends AppWidgetProvider

09

{

10	//当Widget第一次被启动时，启动配套服务

11

@Override

12	public void onEnabled(Context context) {

13	context.startService(new Intent(context,

14

15	WidgetUpdateService.class));

16

}

17

18	//当Widget更新时，启动配套服务

19

@Override

20	public void onUpdate(Context context, AppWidgetManager

21

22	appWidgetManager,

23	int appWidgetIds[]) {

24	super.onUpdate(context, appWidgetManager, appWidgetIds);

25	context.startService(new Intent(context,

26

27	WidgetUpdateService.class));

28

}

29

30	// 当桌面上这个widget的所有实体都被删除后，停止配套服务

31

@Override

32	public void onDisabled(Context context) {

33	context.stopService(new Intent(context, WidgetUpdateService.class));

34

}

35

}

  编写配套的Service。 

中注册这个服务。

查看源码 打印 ?

1	<service android:name=".WidgetUpdateService" android:enabled="true" />

 

然后编写Java 代码：

查看源码 打印 ?

001	package com.billhoo.study;

002

003	import android.app.Service;

004	import android.appwidget.AppWidgetManager;

005	import android.content.BroadcastReceiver;

006	import android.content.ComponentName;

007	import android.content.Context;

008	import android.content.Intent;

009	import android.content.IntentFilter;

010	import android.os.BatteryManager;

011	import android.os.IBinder;

012	import android.widget.RemoteViews;

013

014	//用以根据电池电量更新而刷新桌面Widget的服务

015	public class WidgetUpdateService extends Service {

016

@Override

017	public IBinder onBind(Intent intent) {

018	return null;

019

}

020

021

@Override

022	public void onStart(Intent intent, int startId) {

023	// 向系统注册电池电量更新广播,只接受带有ACTION_BATTERRY_CHANGED事件的Intent

024	registerReceiver(this.bCR, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));

025

026	bCR = new BroadcastReceiver() {

027

@Override

028	public void onReceive(Context context, Intent intent) {

029	int level = intent.getIntExtra("level", 0);

030	int scale = intent.getIntExtra("scale", 100);

031	int status = intent.getIntExtra("status", 0);

032	int batteryHealth = level * 100 / scale;

033	int icon = 0;

034

035	AppWidgetManager widgetManager = AppWidgetManager.getInstance(context);

036	RemoteViews widgetView = new RemoteViews(context.getPackageName(),

037	R.layout.monitor_widget_layout);

038

039

// 若正在充电

040	if (status == BatteryManager.BATTERY_STATUS_CHARGING) {

041	icon = getChargingIcon(batteryHealth);

042	widgetView.setImageViewResource(R.id.monitor_widget_view, icon

043

044

);

045

} else

046	widgetView.setImageViewResource(R.id.monitor_widget_view,

047	getStateIcon(batteryHealth));

048	widgetManager.updateAppWidget(new ComponentName(context,

049	MonitorWidgetProvider.class), widgetView);

050

}

051

};

052

}

053

054	private BroadcastReceiver bCR = null;

055

056	// 获取电池状态图标

057	private int getStateIcon(int batteryHealth) {

058	if (batteryHealth >= 0 || batteryHealth <= 100)

059	return batteryStateIcon[batteryHealth / 5];

060	return R.drawable.vertical_battery_unknown;

061

}

062

063	// 获得对应的充电状态图标

064	private int getChargingIcon(int batteryHealth) {

065	if (batteryHealth >= 0 && batteryHealth < 5)

066	return R.drawable.vertical_charging_00;

067	if (batteryHealth >= 5 && batteryHealth < 10)

068	return R.drawable.vertical_charging_01;

069	if (batteryHealth >= 10 && batteryHealth < 15)

070	return R.drawable.vertical_charging_02;

071	if (batteryHealth >= 15 && batteryHealth < 20)

072	return R.drawable.vertical_charging_03;

073	if (batteryHealth >= 20 && batteryHealth < 25)

074	return R.drawable.vertical_charging_04;

075	if (batteryHealth >= 25 && batteryHealth < 30)

076	return R.drawable.vertical_charging_05;

077	if (batteryHealth >= 30 && batteryHealth < 35)

078	return R.drawable.vertical_charging_06;

079	if (batteryHealth >= 35 && batteryHealth < 40)

080	return R.drawable.vertical_charging_07;

081	if (batteryHealth >= 40 && batteryHealth < 45)

082	return R.drawable.vertical_charging_08;

083	if (batteryHealth >= 45 && batteryHealth < 50)

084	return R.drawable.vertical_charging_09;

085	if (batteryHealth >= 50 && batteryHealth < 55)

086	return R.drawable.vertical_charging_10;

087	if (batteryHealth >= 55 && batteryHealth < 60)

088	return R.drawable.vertical_charging_11;

089	if (batteryHealth >= 60 && batteryHealth < 65)

090	return R.drawable.vertical_charging_12;

091	if (batteryHealth >= 65 && batteryHealth < 70)

092	return R.drawable.vertical_charging_13;

093	if (batteryHealth >= 70 && batteryHealth < 75)

094	return R.drawable.vertical_charging_14;

095	if (batteryHealth >= 75 && batteryHealth < 80)

096	return R.drawable.vertical_charging_15;

097	if (batteryHealth >= 80 && batteryHealth < 85)

098	return R.drawable.vertical_charging_16;

099	if (batteryHealth >= 85 && batteryHealth < 90)

100	return R.drawable.vertical_charging_17;

101	if (batteryHealth >= 90 && batteryHealth < 95)

102	return R.drawable.vertical_charging_18;

103	if (batteryHealth >= 95 && batteryHealth < 100)

104	return R.drawable.vertical_charging_19;

105	if (batteryHealth == 100)

106	return R.drawable.vertical_battery_full;

107	return R.drawable.stat_sys_battery_unknown;

108

}

109

110	private int batteryStateIcon[] = { 0x7f02007d, 0x7f02007e, 0x7f02007f,

111	0x7f020080, 0x7f020081, 0x7f020082, 0x7f020083, 0x7f020084, 0x7f020085,

112	0x7f020086, 0x7f020087, 0x7f020088, 0x7f020089, 0x7f02008a, 0x7f02008b,

113	0x7f02008c, 0x7f02008d, 0x7f02008e, 0x7f02008f, 0x7f020090, 0x7f020091 };

114

}

 

自带的电池图标了，何乐不为？

原文：http://www.open-open.com/lib//view/open1327829183952.html