取得手机电池的剩余量

来源：互联网发布：c语言c java哪个难编辑：程序博客网时间：2024/06/10 13:24

/* * 取得手机电池的剩余量 * Android API中的BroadcastReceiver(Android.content.BroadcastReceiver) * 类有点像Button中的Listener，当Receiver被注册后，会在后台等待其他程序 * 的调用，程序将通过注册BroadcastReceiver时设置的IntentFilter来捕捉系统 * 发出的Intent.ACTION_BATTERY_CHANGED这个action,再以此取得手机电池的剩 * 余量。 */

import 略;

public class Ex06_02Activity extends Activity {private int intLevel;private int intScale;private Button mButton01;private AlertDialog d;// 创建BroadcastReceiverprivate BroadcastReceiver mBatInfoReveiver = new BroadcastReceiver() {@Overridepublic void onReceive(Context context, Intent intent) {// TODO Auto-generated method stubString action = intent.getAction();// 如果捕捉到action是ACRION_BATTERY_CHANGED// 就运行onBatteryInfoReveiver()if (intent.ACTION_BATTERY_CHANGED.equals(action)) {intLevel = intent.getIntExtra("level", 0);intScale = intent.getIntExtra("scale", 100);onBatteryInfoReceiver(intLevel, intScale);}}};/** Called when the activity is first created. */@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);mButton01 = (Button) findViewById(R.id.myButton1);mButton01.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {// TODO Auto-generated method stub// 注册一个BroadcastReceiver，作为访问电池计量之用registerReceiver(mBatInfoReveiver, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));}});}// 拦截到ACTION_BATTRY_CHANGED后要执行的动作private void onBatteryInfoReceiver(int intLevel, int intScale) {// TODO Auto-generated method stubd = new AlertDialog.Builder(Ex06_02Activity.this).create();d.setTitle(R.string.str_dialog_title);d.setMessage(getResources().getString(R.string.str_dialog_body)+ String.valueOf(intLevel * 100 / intScale) + "%");d.setButton(getResources().getString(R.string.str_button2),new DialogInterface.OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {// TODO Auto-generated method stub// 取消注册，并关闭对话框unregisterReceiver(mBatInfoReveiver);d.dismiss();}});d.show();};}

下面我们来看看程序运行后的结果：

在Android API中有提到，要注册Intent.ACTION_BATTERY_CHANGED的Receiver只能在程序中以
Context.register Receiver()方法来注册，而不能直接在AndroidManifest.xml中注册。