Android - 电池状态

为了解决电池图标的问题，顺带看了看电池信息的获取方法 ；自己写了一个小栗子，来验证一下效果

电池的信息，一般都在BatteryManager里面，信息是用广播发出的。我们更新信息需要一个广播接收器

注册一个广播接收器，接收  Intent.ACTION_BATTERY_CHANGED ，从intent中读出想要的电池信息

比如 BatteryManager.EXTRA_STATUS     BatteryManager.BATTERY_STATUS_CHARGING  等等

在Android 5.1中，电池信息可以在Settings - Battery 里面找到

 package com.example.chargingwatching;

 import android.app.Activity;
 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.os.BatteryManager;
 import android.os.Bundle;
 import android.view.WindowManager;
 import android.widget.TextView;

 public class MainActivity extends Activity {
     private TextView chargeStatus;
     private TextView LevelDigit;
     private TextView percentView;
     private int rustLevel = 0;    /* battery level */
     private int windowWidth = 0;
     private WindowManager mWindowManager;

     private BroadcastReceiver mBatteryStatuReceiver = new BroadcastReceiver() {
         int status;    // current battery status
         int plugType;
         public void onReceive(Context context, Intent intent)    {

             rustLevel = (int)(100f
                     * intent.getIntExtra(BatteryManager.EXTRA_LEVEL, 0)
                     / intent.getIntExtra(BatteryManager.EXTRA_SCALE, 100));

             LevelDigit.setText("  " + rustLevel + "%");

             percentView.setWidth((int)(windowWidth * rustLevel /100));
             status = intent.getIntExtra(BatteryManager.EXTRA_STATUS,
                     BatteryManager.BATTERY_STATUS_UNKNOWN);
             plugType = intent.getIntExtra(BatteryManager.EXTRA_PLUGGED, 0);

             if(status == BatteryManager.BATTERY_STATUS_CHARGING) {
                 if(plugType == BatteryManager.BATTERY_PLUGGED_AC) {
                     chargeStatus.setText(R.string.ac_charging);
                 } else if (plugType == BatteryManager.BATTERY_PLUGGED_USB) {
                     chargeStatus.setText(R.string.usb_charging);
                 }
             } else if (status == BatteryManager.BATTERY_STATUS_FULL) {
                 if(plugType == BatteryManager.BATTERY_PLUGGED_AC) {
                     chargeStatus.setText(R.string.full_ac);
                 } else if (plugType == BatteryManager.BATTERY_PLUGGED_USB) {
                     chargeStatus.setText(R.string.full_usb);
                 }
             } else if(status == BatteryManager.BATTERY_STATUS_NOT_CHARGING) {
                 chargeStatus.setText(R.string.uncharge);
             } else if(status == BatteryManager.BATTERY_STATUS_DISCHARGING) {
                 chargeStatus.setText(R.string.discharging);
             } else {
                 chargeStatus.setText(R.string.unknown);
             }
         }
     };

     @SuppressWarnings("deprecation")
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.watch_charging);
         chargeStatus = (TextView)findViewById(R.id.tv_charge);
         LevelDigit = (TextView) findViewById(R.id.tv_battery_level_digit);
         percentView = (TextView) findViewById(R.id.percent_view);

         mWindowManager = this.getWindowManager();
         windowWidth = mWindowManager.getDefaultDisplay().getWidth();

         IntentFilter filter = new IntentFilter();
         filter.addAction(Intent.ACTION_BATTERY_CHANGED);
         registerReceiver(mBatteryStatuReceiver, filter);
     }
 }

以下是简单的布局文件

主体是LinearLayout，放一个TextView来显示电池状态，一个TextView来显示电量百分比

一个简陋的电量条，拿TextView来冒充的

 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:orientation="vertical" >

     <TextView
         android:id="@+id/tv_charge"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:text="Detecting..."
         android:textSize="20sp"
         />

     <LinearLayout
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:orientation="horizontal" >

         <TextView
             android:id="@+id/tv_battery_level"
             android:layout_width="wrap_content"
             android:layout_height="match_parent"
             android:text="@string/battery_level"
             android:textSize="20sp"/>

         <TextView
             android:id="@+id/tv_battery_level_digit"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
             android:textSize="20sp"/>
     </LinearLayout>

     <TextView
         android:id="@+id/percent_view"
         android:layout_height="20dp"
         android:layout_width="wrap_content"
         android:background="#00AA00"
         />
 </LinearLayout>