获取手机电量

package cn.com;

import android.app.Activity;
import android.app.Dialog;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.TextView;

public class BatteryInfo extends Activity
{
  /* 变量声明 */
  private int intLevel;
  private int intScale;
  private Button mButton01;

  /* 创建BroadcastReceiver */
  private BroadcastReceiver mBatInfoReceiver = new BroadcastReceiver()
  {
    public void onReceive(Context context, Intent intent)
    {
      String action = intent.getAction();
      /*
       * 如果捕捉到的action是ACTION_BATTERY_CHANGED， 就运行onBatteryInfoReceiver()
       */
      if (Intent.ACTION_BATTERY_CHANGED.equals(action))
      {
        intLevel = intent.getIntExtra("level", 0);
        intScale = intent.getIntExtra("scale", 100);
        Log.i("", "intLevel = " + intLevel);
        Log.i("", "intScale = " + intScale);
        onBatteryInfoReceiver(intLevel, intScale);
      }
    }
  };

  /** Called when the activity is first created. */
  @Override
  public void onCreate(Bundle savedInstanceState)
  {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    mButton01 = (Button) findViewById(R.id.myButton1);
    mButton01.setOnClickListener(new Button.OnClickListener()
    {
      public void onClick(View v)
      {

        // 注册一个系统 BroadcastReceiver，作为访问电池计量之用
        // 這個不能直接在AndroidManifest.xml中註冊
        registerReceiver(mBatInfoReceiver, new IntentFilter(
            Intent.ACTION_BATTERY_CHANGED));
      }
    });
  }

  /* 捕捉到ACTION_BATTERY_CHANGED时要运行的method */
  public void onBatteryInfoReceiver(int intLevel, int intScale)
  {
    /* create 跳出的对话窗口 */
    final Dialog d = new Dialog(BatteryInfo.this);
    d.setTitle(R.string.str_dialog_title);
    d.setContentView(R.layout.mydialog);

    /* 创建一个背景模糊的Window，且将对话窗口放在前景 */
    Window window = d.getWindow();
    window.setFlags(WindowManager.LayoutParams.FLAG_BLUR_BEHIND,
        WindowManager.LayoutParams.FLAG_BLUR_BEHIND);

    /* 将取得的电池计量显示于Dialog中 */
    TextView mTextView02 = (TextView) d.findViewById(R.id.myTextView2);
    mTextView02.setText(getResources()
        .getText(R.string.str_dialog_body)
        + String.valueOf(intLevel * 100 / intScale) + "%");

    /* 设置返回主画面的按钮 */
    Button mButton02 = (Button) d.findViewById(R.id.myButton2);
    mButton02.setOnClickListener(new Button.OnClickListener()
    {
      public void onClick(View v)
      {
        /* 反注册Receiver，并关闭对话窗口 */
        unregisterReceiver(mBatInfoReceiver);
        d.dismiss();
      }
    });
    d.show();
  }
}

代码里还用到了自定义的Dialog布局:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
	android:background="@drawable/white" android:orientation="vertical"
	android:layout_width="fill_parent" android:layout_height="fill_parent">
	<TextView android:id="@+id/myTextView2" android:layout_width="fill_parent"
		android:layout_height="wrap_content" android:textColor="@drawable/blue"
		android:textSize="16sp" android:gravity="center" android:padding="10px">
	</TextView>
	<Button android:id="@+id/myButton2" android:layout_width="wrap_content"
		android:layout_height="wrap_content" android:text="@string/str_button2">
	</Button>
</LinearLayout>