Android之手机电池电量应用

原理概述：

手机电池电量的获取在应用程序的开发中也很常用，Android系统中手机电池电量发生变化的消息是通过Intent广播来实现的，常用的Intent的Action有Intent.ACTION_BATTERY_CHANGED（电池电量发生改变时）、Intent.ACTION_BATTERY_LOW（电池电量达到下限时）、和Intent.ACTION_BATTERY_OKAY（电池电量从低恢复到高时）。

当需要在程序中获取电池电量的信息时，需要为应用程序注册BroadcastReceiver组件，当特定的Action事件发生时，系统将会发出相应的广播，应用程序就可以通过BroadcastReceiver来接受广播，并进行相应的处理。

main.xml布局文件

              <?        xml version        =        "        1.0        "         encoding        =        "        utf-8        "        ?>        
        <        LinearLayout xmlns:android        =        "        http://schemas.android.com/apk/res/android        "        
 android:orientation        =        "        vertical        "         
 android:layout_width        =        "        fill_parent        "        
 android:layout_height        =        "        fill_parent        "        >        
         <        ToggleButton android:id        =        "        @+id/tb        "        
 android:layout_width        =        "        fill_parent        "        
 android:layout_height        =        "        wrap_content        "         
 android:textOn        =        "        停止获取电量信息        "        
 android:textOff        =        "        获取电量信息        "                 />        
         <        TextView android:id        =        "        @+id/tv        "         
 android:layout_width        =        "        fill_parent        "        
 android:layout_height        =        "        wrap_content        "                 />        
        </        LinearLayout        >

BatteryActivity类

              package         com.ljq.activity;

        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.widget.CompoundButton;
        import         android.widget.TextView;
        import         android.widget.ToggleButton;
        import         android.widget.CompoundButton.OnCheckedChangeListener;


        public                 class         BatteryActivity         extends         Activity {
         private         ToggleButton tb        =        null        ;
         private         TextView tv        =        null        ;
         private         BatteryReceiver receiver        =        null        ;
 
 
 @Override
         public                 void         onCreate(Bundle savedInstanceState) {
         super        .onCreate(savedInstanceState);
 setContentView(R.layout.main);
 
 receiver        =        new         BatteryReceiver();
 tv        =        (TextView)findViewById(R.id.tv);
 tb        =        (ToggleButton)findViewById(R.id.tb);
 tb.setOnCheckedChangeListener(        new         OnCheckedChangeListener(){
         public                 void         onCheckedChanged(CompoundButton compoundButton,         boolean         isChecked) {
         //        获取电池电量        
                 if        (isChecked){
 IntentFilter filter        =        new         IntentFilter(Intent.ACTION_BATTERY_CHANGED);
 registerReceiver(receiver, filter);        //        注册BroadcastReceiver        
         }        else         {
         //        停止获取电池电量        
         unregisterReceiver(receiver);
 tv.setText(        null        );
 }
 
 }
 });
 
 }
 
         private                 class         BatteryReceiver         extends         BroadcastReceiver{
 @Override
         public                 void         onReceive(Context context, Intent intent) {
         int         current        =        intent.getExtras().getInt(        "        level        "        );        //        获得当前电量        
                 int         total        =        intent.getExtras().getInt(        "        scale        "        );        //        获得总电量        
                 int         percent        =        current        *        100        /        total;
 tv.setText(        "        现在的电量是        "        +        percent        +        "        %。        "        );
 }
 }
 

}

运行结果

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