android 电量

引用：http://onetiger.net/?p=1057

在android中，要获得手机的电量的话，可以通过intent广播去实现，监听
action_battery_changed，例子如下：

package com.liao;
import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.widget.TextView;

public class BatteryLevelActivity extends Activity {
/** Called when the activity is first created. */
private TextView batterLevel;

@Override
/**
* Called when the current activity is first created.
*/
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.main);
batterLevel = (TextView) this.findViewById(R.id.batteryLevel);
batteryLevel();
}

private void batteryLevel() {
BroadcastReceiver batteryLevelReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
context.unregisterReceiver(this);
int rawlevel = intent.getIntExtra("level", -1);//获得当前电量
int scale = intent.getIntExtra("scale", -1);
//获得总电量
int level = -1;
if (rawlevel >= 0 && scale > 0) {
level = (rawlevel * 100) / scale;
}
batterLevel.setText("Battery Level Remaining: " + level + "%");
}
};
IntentFilter batteryLevelFilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
registerReceiver(batteryLevelReceiver, batteryLevelFilter);
}

}

如果是2。0后的SDK，也可以这样：
public void onReceive(Context context, Intent intent) {
context.unregisterReceiver(this);
int rawlevel = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, -1);
int scale = intent.getIntExtra(BatteryManager.EXTRA_SCALE, -1);

就是修改一下类而已