获取Android设备电池电量状态

获取Android设备电池电量状态

自己在网上搜索了一下，将其总结如下：

Android开发者可以利用BroadcastReceiver机制，获取电池电量变化的ACTION_BATTERY_CHANGED intent，进而获取当前android设备的电池状态。

具体操作步骤：

1. 创建一个监听ACTION_BATTERY_CHANGED事件的intentFilter。

2. 创建一个BroadcastReceiver对象，该对象可以接收broadcast intent。

3. 注册BroadcastReceiver对象来监听ACTION_BATTERY_CHANGED事件。

4. 在BroadcastReceiver对象中，重写onReceive方法，在onReceive方法的传入参数intent里获取需要的电池状态信息。

5. 在生命周期结束时，取消step4中的注册。

示例代码：

Java文件

public   class  BatteryMonitorActivity  extends  Activity {

     private  TextView batterLevel;
     private  BroadcastReceiver batteryLevelRcvr;
     private  IntentFilter batteryLevelFilter;
    
    @Override
     public   void  onCreate(Bundle savedInstanceState) {
         super .onCreate(savedInstanceState);
        setContentView(R.layout.main);
        batterLevel  =  (TextView) findViewById(R.id.batteryLevel);
        monitorBatteryState();
    }
    
    @Override
     protected   void  onDestroy() {
         super .onDestroy();
        unregisterReceiver(batteryLevelRcvr);
    }
    
     private   void  monitorBatteryState() {
        batteryLevelRcvr  =   new  BroadcastReceiver() {

             public   void  onReceive(Context context, Intent intent) {
                StringBuilder sb  =   new  StringBuilder();
                 int  rawlevel  =  intent.getIntExtra( " level " ,  - 1 );
                 int  scale  =  intent.getIntExtra( " scale " ,  - 1 );
                 int  status  =  intent.getIntExtra( " status " ,  - 1 );
                 int  health  =  intent.getIntExtra( " health " ,  - 1 );
                 int  level  =   - 1 ;  //  percentage, or -1 for unknown
                 if  (rawlevel  >=   0   &&  scale  >   0 ) {
                    level  =  (rawlevel  *   100 )  /  scale;
                }
                sb.append( " The phone " );
                 if  (BatteryManager.BATTERY_HEALTH_OVERHEAT  ==  health) {
                    sb.append( " 's battery feels very hot! " );
                }  else  {
                     switch  (status) {
                         case  BatteryManager.BATTERY_STATUS_UNKNOWN:
                            sb.append( " no battery. " );
                             break ;
                         case  BatteryManager.BATTERY_STATUS_CHARGING:
                            sb.append( " 's battery " );
                             if  (level  <=   33 )
                                sb.append( "  is charging, battery level is low "   +   " [ "   +  level  +   " ] " );
                             else   if  (level  <=   84 )
                                sb.append( "  is charging. "   +   " [ "   +  level  +   " ] " );
                             else
                                sb.append( "  will be fully charged. " );
                             break ;
                         case  BatteryManager.BATTERY_STATUS_DISCHARGING:
                         case  BatteryManager.BATTERY_STATUS_NOT_CHARGING:
                             if  (level  ==   0 )
                                sb.append( "  needs charging right away. " );
                             else   if  (level  >   0   &&  level  <=   33 )
                                sb.append( "  is about ready to be recharged, battery level is low " +   " [ "   +  level  +   " ] " );
                             else
                                sb.append( " 's battery level is "   +   " [ "   +  level  +   " ] " );
                             break ;
                         case  BatteryManager.BATTERY_STATUS_FULL:
                            sb.append( "  is fully charged. " );
                             break ;
                         default :
                            sb.append( " 's battery is indescribable! " );
                             break ;
                    }
                }
                sb.append( '   ' );
                batterLevel.setText(sb.toString());
            }
        };
        batteryLevelFilter  =   new  IntentFilter(Intent.ACTION_BATTERY_CHANGED);
        registerReceiver(batteryLevelRcvr, batteryLevelFilter);
    }
}

布局文件

<? xml version = " 1.0 "  encoding = " utf-8 " ?>
< LinearLayout xmlns:android = " http://schemas.android.com/apk/res/android "
    android:layout_width = " fill_parent "
    android:layout_height = " fill_parent "
    android:orientation = " vertical "   >
     < TextView         
        android:id = " @+id/batteryLevel "
        android:layout_width = " fill_parent "  
        android:layout_height = " fill_parent "  
        android:gravity = " center_vertical|center_horizontal "
        android:textSize = " 50dip " >  
     </ TextView >
</ LinearLayout >

由于移动设备电池电量的局限，使得电池电量的控制成为评价一个移动应用好坏的重要标准。个人认为一个电量控制较好的应用，应该是一方面合理安排耗电操作，并且follow android开发中那些省电的best practice，以保证移动设备的用电效率，另一方面，应该识别当前电池电量状态进行耗电操作调整，例如，当电池电量较低时，减小耗电操作的次数，以提供友好的用电方式。