主要代码

package com.bro;

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.view.View;

import android.view.Window;

import android.view.WindowManager;

import android.widget.Button;

import android.widget.TextView;

public class Broadcast extends Activity {

private int intLevel;

private int intScale;

private Button mButton01;

    /** 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(){

@Override

public void onClick(View v) {

//注册一个系统 BroadcastReceiver， 作为访问电池计量之用

registerReceiver(batInfoReceiver, new IntentFilter(

Intent.ACTION_BATTERY_CHANGED));

}

        

        });

    }

    

    private BroadcastReceiver batInfoReceiver = new BroadcastReceiver(){

@Override

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);

onBatteryInfoReceiver(intLevel,intScale);

}

}

    

    };

    

    //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(Broadcast.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与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(){

@Override

public void onClick(View v) {

unregisterReceiver(batInfoReceiver);

d.dismiss();

}

    

    });

    d.show();

    }

}