Android - 電池狀态

為了解決電池圖示的問題，順帶看了看電池資訊的擷取方法 ；自己寫了一個小栗子，來驗證一下效果

電池的資訊，一般都在BatteryManager裡面，資訊是用廣播發出的。我們更新資訊需要一個廣播接收器

注冊一個廣播接收器，接收  Intent.ACTION_BATTERY_CHANGED ，從intent中讀出想要的電池資訊

比如 BatteryManager.EXTRA_STATUS     BatteryManager.BATTERY_STATUS_CHARGING  等等

在Android 5.1中，電池資訊可以在Settings - Battery 裡面找到

1 package com.example.chargingwatching;
 2 
 3 import android.app.Activity;
 4 import android.content.BroadcastReceiver;
 5 import android.content.Context;
 6 import android.content.Intent;
 7 import android.content.IntentFilter;
 8 import android.os.BatteryManager;
 9 import android.os.Bundle;
10 import android.view.WindowManager;
11 import android.widget.TextView;
12 
13 public class MainActivity extends Activity {
14     private TextView chargeStatus;
15     private TextView LevelDigit;
16     private TextView percentView;
17     private int rustLevel = 0;    /* battery level */
18     private int windowWidth = 0;    
19     private WindowManager mWindowManager;
20 
21     private BroadcastReceiver mBatteryStatuReceiver = new BroadcastReceiver() {
22         int status;    // current battery status
23         int plugType; 
24         public void onReceive(Context context, Intent intent)    {
25 
26             rustLevel = (int)(100f 
27                     * intent.getIntExtra(BatteryManager.EXTRA_LEVEL, 0)
28                     / intent.getIntExtra(BatteryManager.EXTRA_SCALE, 100));
29 
30             LevelDigit.setText("  " + rustLevel + "%");
31             
32             percentView.setWidth((int)(windowWidth * rustLevel /100));     
33             status = intent.getIntExtra(BatteryManager.EXTRA_STATUS,
34                     BatteryManager.BATTERY_STATUS_UNKNOWN);
35             plugType = intent.getIntExtra(BatteryManager.EXTRA_PLUGGED, 0);
36 
37             if(status == BatteryManager.BATTERY_STATUS_CHARGING) {
38                 if(plugType == BatteryManager.BATTERY_PLUGGED_AC) {
39                     chargeStatus.setText(R.string.ac_charging);
40                 } else if (plugType == BatteryManager.BATTERY_PLUGGED_USB) {
41                     chargeStatus.setText(R.string.usb_charging);
42                 }
43             } else if (status == BatteryManager.BATTERY_STATUS_FULL) {
44                 if(plugType == BatteryManager.BATTERY_PLUGGED_AC) {
45                     chargeStatus.setText(R.string.full_ac);
46                 } else if (plugType == BatteryManager.BATTERY_PLUGGED_USB) {
47                     chargeStatus.setText(R.string.full_usb);
48                 }
49             } else if(status == BatteryManager.BATTERY_STATUS_NOT_CHARGING) {
50                 chargeStatus.setText(R.string.uncharge);
51             } else if(status == BatteryManager.BATTERY_STATUS_DISCHARGING) {
52                 chargeStatus.setText(R.string.discharging);
53             } else {
54                 chargeStatus.setText(R.string.unknown);
55             }
56         }
57     };
58 
59     @SuppressWarnings("deprecation")
60     @Override
61     public void onCreate(Bundle savedInstanceState) {
62         super.onCreate(savedInstanceState);
63         setContentView(R.layout.watch_charging);
64         chargeStatus = (TextView)findViewById(R.id.tv_charge);
65         LevelDigit = (TextView) findViewById(R.id.tv_battery_level_digit);
66         percentView = (TextView) findViewById(R.id.percent_view);
67 
68         mWindowManager = this.getWindowManager();
69         windowWidth = mWindowManager.getDefaultDisplay().getWidth();
70 
71         IntentFilter filter = new IntentFilter();    
72         filter.addAction(Intent.ACTION_BATTERY_CHANGED);
73         registerReceiver(mBatteryStatuReceiver, filter);
74     }
75 }      

以下是簡單的布局檔案

主體是LinearLayout，放一個TextView來顯示電池狀态，一個TextView來顯示電量百分比

一個簡陋的電量條，拿TextView來冒充的

1 <?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     android:layout_width="match_parent"
 4     android:layout_height="match_parent"
 5     android:orientation="vertical" >
 6 
 7     <TextView
 8         android:id="@+id/tv_charge"
 9         android:layout_width="match_parent"
10         android:layout_height="wrap_content"
11         android:text="Detecting..." 
12         android:textSize="20sp"
13         />
14 
15     <LinearLayout
16         android:layout_width="match_parent"
17         android:layout_height="wrap_content"
18         android:orientation="horizontal" >
19 
20         <TextView
21             android:id="@+id/tv_battery_level"
22             android:layout_width="wrap_content"
23             android:layout_height="match_parent"
24             android:text="@string/battery_level" 
25             android:textSize="20sp"/>
26 
27         <TextView
28             android:id="@+id/tv_battery_level_digit"
29             android:layout_width="match_parent"
30             android:layout_height="match_parent" 
31             android:textSize="20sp"/>
32     </LinearLayout>
33 
34     <TextView 
35         android:id="@+id/percent_view"
36         android:layout_height="20dp"
37         android:layout_width="wrap_content"
38         android:background="#00AA00"
39         />
40 </LinearLayout>