接收系統廣播訊息之監聽手機電量變化

當手機電量發生改變時，系統會對外發送Intent的Action為android.intent.action.BATTERY_CHANGED常量的廣播；當手機電量過低時，系統會對外發送Intent的Action為android.intent.action.BATTERY_LOW常量的廣播。

當手機電池從電量不足狀態恢複時，系統會對外發送Intent的Action為android.intent.action.BATTERY_OKAY常量的廣播。

下面通過一個簡單一實例來示範：

Receiver：

 

package com.home.receiver;  import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.os.Bundle; import android.widget.Toast;  public class BatteryReceiver extends BroadcastReceiver {      @Override     public void onReceive(Context context, Intent intent) {         if (Intent.ACTION_BATTERY_OKAY.equals(intent.getAction())) {             Toast.makeText(context, "電量已恢複，可以使用!", Toast.LENGTH_LONG).show();         }         if (Intent.ACTION_BATTERY_LOW.equals(intent.getAction())) {             Toast.makeText(context, "電量過低，請儘快充電！", Toast.LENGTH_LONG).show();         }         if (Intent.ACTION_BATTERY_CHANGED.equals(intent.getAction())) {             Bundle bundle = intent.getExtras();             // 擷取當前電量              int current = bundle.getInt("level");             // 擷取總電量              int total = bundle.getInt("scale");             StringBuffer sb = new StringBuffer();             sb.append("當前電量為：" + current * 100 / total + "%" + "  ");             // 如果當前電量小於總電量的15%              if (current * 1.0 / total < 0.15) {                 sb.append("電量過低，請儘快充電！");             } else {                 sb.append("電量足夠，請放心使用！");             }             Toast.makeText(context, sb.toString(), Toast.LENGTH_LONG).show();         }      }  } package com.home.receiver;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.os.Bundle;import android.widget.Toast;public class BatteryReceiver extends BroadcastReceiver { @Override public void onReceive(Context context, Intent intent) {  if (Intent.ACTION_BATTERY_OKAY.equals(intent.getAction())) {   Toast.makeText(context, "電量已恢複，可以使用!", Toast.LENGTH_LONG).show();  }  if (Intent.ACTION_BATTERY_LOW.equals(intent.getAction())) {   Toast.makeText(context, "電量過低，請儘快充電！", Toast.LENGTH_LONG).show();  }  if (Intent.ACTION_BATTERY_CHANGED.equals(intent.getAction())) {   Bundle bundle = intent.getExtras();   // 擷取當前電量   int current = bundle.getInt("level");   // 擷取總電量   int total = bundle.getInt("scale");   StringBuffer sb = new StringBuffer();   sb.append("當前電量為：" + current * 100 / total + "%" + "  ");   // 如果當前電量小於總電量的15%   if (current * 1.0 / total < 0.15) {    sb.append("電量過低，請儘快充電！");   } else {    sb.append("電量足夠，請放心使用！");   }   Toast.makeText(context, sb.toString(), Toast.LENGTH_LONG).show();  } }}

配置Receiver：

receiver android:name="com.home.receiver.BatteryReceiver">           <intent-filter>               <action android:name="android.intent.action.BATTERY_CHANGED" />               <action android:name="android.intent.action.BATTERY_OKAY"/>               <action android:name="android.intent.action.BATTERY_LOW"/>           </intent-filter>         </receiver>  <receiver android:name="com.home.receiver.BatteryReceiver">           <intent-filter>               <action android:name="android.intent.action.BATTERY_CHANGED" />               <action android:name="android.intent.action.BATTERY_OKAY"/>               <action android:name="android.intent.action.BATTERY_LOW"/>           </intent-filter>        </receiver>