Android 获取手机电量

package com.example.androidtest;import android.os.Bundle;import android.app.Activity;import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.content.IntentFilter;import android.view.Menu;import android.widget.TextView;public class MainActivity extends Activity {private TextView textView1=null;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);textView1=(TextView)findViewById(R.id.textView1);batteryLevel();}/*获取电量*/private void batteryLevel() {          BroadcastReceiver batteryLevelReceiver = new BroadcastReceiver() {              public void onReceive(Context context, Intent intent) {                 context.unregisterReceiver(this);                 /*获得当前电量  */                int rawlevel = intent.getIntExtra("level", -1);                /*获得总电量  */                int scale = intent.getIntExtra("scale", -1);                int level = -1;                  if (rawlevel >= 0 && scale > 0) {                      level = (rawlevel * 100) / scale;                  }                  textView1.setText("Battery Level Remaining: " + level + "%");              }          };          IntentFilter batteryLevelFilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);          registerReceiver(batteryLevelReceiver, batteryLevelFilter);      } @Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.main, menu);return true;}}