android 显示电量的widget

这个显示电量的widget很多应用中都附带的有这个功能，但我自己手机上就只想要这个功能，网上找了半天，全都是那种一个庞大的应用中带了这么个小功能，但是那些功能我又不需要（算有点强迫症吧。。），于是一怒之下，干脆自己写个。。。

这个东西写其实也很简单，网上的例子也有很多了，无非就是启动个后台service去监听电量变化然后显示到widget上,先来张效果图

我这里面还多加了个监听充放电的状态变化（左边那个图标会改变），另外这个工程里面是没有活动的activity，安装之后点一下应用程序图标就会直接弹出来，然后在桌面的添加widget中找到有个叫PowerWidget的小工具拿出来用即可

下面直接把代码贴出来了，3个class，最下面有项目工程包的下载地址

PowerWidgetActivity.java

public class PowerWidgetActivity extends Activity {

    public static final String TAG = "PowerWidget";
    
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //setContentView(R.layout.main);

        overridePendingTransition(0, 0);
        Log.i(TAG, " on WidgetConf ... ");
        setResult(RESULT_CANCELED);

        // Find the widget id from the intent.
        Intent intent = getIntent();
        Bundle extras = intent.getExtras();
        int mAppWidgetId = 0;
        if (extras != null) {
            mAppWidgetId = extras.getInt(AppWidgetManager.EXTRA_APPWIDGET_ID, AppWidgetManager.INVALID_APPWIDGET_ID);
        }

        // If they gave us an intent without the widget id, just bail.
        if (mAppWidgetId == AppWidgetManager.INVALID_APPWIDGET_ID) {
            finish();
        }

        // return OK
        Intent resultValue = new Intent();
        resultValue.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, mAppWidgetId);

        setResult(RESULT_OK, resultValue);
        finish();
        
    }
    
    
}

BatteyService.java

package com.fly.power_widget;

import android.app.Service;
import android.appwidget.AppWidgetManager;
import android.content.BroadcastReceiver;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.graphics.drawable.Drawable;
import android.os.BatteryManager;
import android.os.IBinder;
import android.util.Log;
import android.widget.ImageView;
import android.widget.RemoteViews;
import android.widget.TextView;

public class BatteyService extends Service {

    public static final String TAG = "PowerWidget";

    public BroadcastReceiver battryReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            Log.d(TAG, "intent->" + intent);
            Log.d(TAG, "action->" + action);
            ComponentName thiswidget = new ComponentName(context, PowerWidget.class);
            AppWidgetManager appmanager = AppWidgetManager.getInstance(context);
            RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.clock_widget);
            if (Intent.ACTION_BATTERY_CHANGED.equals(action)) {
                int level = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, 0);
                int scale = intent.getIntExtra(BatteryManager.EXTRA_SCALE, 100);
                int status = intent.getIntExtra(BatteryManager.EXTRA_STATUS, 0);
                Log.e(TAG, BatteryManager.EXTRA_LEVEL + "->" + level);
                Log.e(TAG, BatteryManager.EXTRA_SCALE + "->" + scale);
                Log.e(TAG, BatteryManager.EXTRA_STATUS + "->" + status);
                views.setTextViewText(R.id.power_percent, "电量:");
                //views.setFloat(R.id.power_percent, "setTextSize", 20);
                //views.setTextColor(R.id.power_percent, 0xffff0000);
                views.setInt(R.id.power_percent_image, "setImageResource", R.drawable.stat_sys_battery_000+level);
            } else if (Intent.ACTION_POWER_CONNECTED.equals(action)) {
                views.setInt(R.id.power_image, "setImageResource", R.drawable.charging);
            } else if (Intent.ACTION_POWER_DISCONNECTED.equals(action)) {
                views.setInt(R.id.power_image, "setImageResource", R.drawable.uncharge);
            }
            appmanager.updateAppWidget(thiswidget, views);
        }
    };

    @Override
    public IBinder onBind(Intent arg0) {
        return null;
    }

    public void onStart(Intent intent, int startId) {
        IntentFilter filter = new IntentFilter();
        filter.addAction(Intent.ACTION_BATTERY_CHANGED);
        filter.addAction(Intent.ACTION_POWER_CONNECTED);
        filter.addAction(Intent.ACTION_POWER_DISCONNECTED);
        registerReceiver(battryReceiver, filter);
    }

    public void onDestroy() {
        unregisterReceiver(battryReceiver);
        super.onDestroy();
    }
}

PowerWidget.java

package com.fly.power_widget;

import android.appwidget.AppWidgetManager;
import android.appwidget.AppWidgetProvider;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.util.Log;
import android.widget.RemoteViews;

public class PowerWidget extends AppWidgetProvider {

    public static final String TAG = "PowerWidget";

    @Override
    public void onReceive(Context context, Intent intent) {
        super.onReceive(context, intent);
        Log.i(TAG, "onReceive!  receive intent ---> " + intent.getAction());
    }

    @Override
    public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
        Intent intent = new Intent(context, BatteyService.class);
        context.startService(intent);
    }

    @Override
    public void onDeleted(Context context, int[] appWidgetIds) {
        Intent intent = new Intent(context, BatteyService.class);
        context.stopService(intent);
    }

    @Override
    public void onEnabled(Context context) {
        Log.i(TAG, "onEnabled!");
    }

    @Override
    public void onDisabled(Context context) {
        Log.i(TAG, "onDisabled!");
    }

}

项目工程包的下载地址：http://download.youkuaiyun.com/detail/chuekup/5210198