Android Widget 小部件(一) 简单实现-优快云博客

在屏幕上加入Widget：或长按屏幕空白处，或找到WidgetPreview App选择。

原生系统4.0下面使用长按方式，4.0及以上打开WIDGETS

创建Widget的一般步骤：
在menifest中

<receiver android:name="com.stone.ui.TimerWidgetProvider">
             <intent-filter>
                 <action android:name="android.appwidget.action.APPWIDGET_UPDATE"/>
                 <!-- 自己定义action -->
                 <action android:name="com.stone.action.start"/>
             </intent-filter>
             <meta-data android:name="android.appwidget.provider"
                 android:resource="@xml/timer_widget_provider"/>
                 <!--  android:resource="" 定义了Widget的信息使用timer_widget_provider.xml描写叙述 -->
</receiver>

Widget描写叙述文件：timer_widget_provider.xml

<?

xml version="1.0" encoding="utf-8"?> <appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android" android:minWidth="180dp" android:minHeight="40dp" android:updatePeriodMillis="5000" android:previewImage="@drawable/ic_launcher" android:initialLayout="@layout/timer_widget" android:resizeMode="horizontal|vertical" android:widgetCategory="keyguard|home_screen" android:configure="com.stone.ui.AppWidgetConfigureActivity" >  </appwidget-provider>

Widget使用的布局：timer_widget.xml

<?xml version="1.0" encoding="utf-8"?

> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="horizontal" android:background="@drawable/widget_background" > <TextView android:id="@+id/counter" android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1" android:gravity="center" android:text="00:00" android:singleLine="true" android:textAppearance="?android:attr/textAppearance"/> <ImageView android:id="@+id/start_stop" android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1" android:scaleType="center" android:src="@android:drawable/ic_media_play"/> </LinearLayout>

处理Widget相关事件的 AppWidgetProvider

package com.stone.ui;

import java.util.Arrays;

import com.stone.R;
import com.stone.service.TimerWidgetService;

import android.app.PendingIntent;
import android.appwidget.AppWidgetHost;
import android.appwidget.AppWidgetManager;
import android.appwidget.AppWidgetProvider;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.text.format.DateUtils;
import android.widget.RemoteViews;

/*
 * AppWidgetProvider 必需要接收android.appwidget.action.APPWIDGET_UPDATE 广播
 * 
 */
public class TimerWidgetProvider extends AppWidgetProvider {
	
	@Override //更新部件时调用，在第1次加入部件时也会调用
	public void onUpdate(Context context, AppWidgetManager appWidgetManager,
			int[] appWidgetIds) {
		super.onUpdate(context, appWidgetManager, appWidgetIds);
		System.out.println("onUpdate widget：" + Arrays.toString(appWidgetIds));
		/*
		 * 构造pendingIntent发广播，onReceive()依据收到的广播，更新
		 */
		Intent intent = new Intent(context, TimerWidgetService.class);
		PendingIntent pendingIntent = PendingIntent.getService(context, 0, intent, 0);
		RemoteViews rv = new RemoteViews(context.getPackageName(), R.layout.timer_widget);
		rv.setOnClickPendingIntent(R.id.start_stop, pendingIntent);
		appWidgetManager.updateAppWidget(appWidgetIds, rv);
	}
	
	@Override	//部件从host中删除
	public void onDeleted(Context context, int[] appWidgetIds) {
		super.onDeleted(context, appWidgetIds);
		System.out.println("onDeleted widget");
	}
	
	@Override //第1次创建时调用。之后再创建不会调用
	public void onEnabled(Context context) {
		super.onEnabled(context);
		System.out.println("onEnabled widget");
	}
	
	@Override //当最后一个部件实例 被删除时 调用  用于清除onEnabled运行的操作
	public void onDisabled(Context context) {
		super.onDisabled(context);
		System.out.println("onDisabled widget");
	}
	
	@Override //
	public void onReceive(Context context, Intent intent) {
		super.onReceive(context, intent);
		System.out.println("onReceive widget");
		/*
		 * 接收 <action android:name="com.stone.action.start"/>
           在其它组件或activity或service中发送这些广播
           
		 */
		if (intent.getAction().equals("com.stone.action.start")) {
			long time = intent.getLongExtra("time", 0);
			 updateWidget(context, time);
			 System.out.println("receive com.stone.action.start");
		}
	}
	
	private void updateWidget(Context context, long time) {
		//RemoteViews处理异进程中的View
		RemoteViews rv = new RemoteViews(context.getPackageName(), R.layout.timer_widget);
		System.out.println("time=" + time);
		rv.setTextViewText(R.id.counter, DateUtils.formatElapsedTime(time / 1000));
		
		AppWidgetManager am = AppWidgetManager.getInstance(context);
		int[] appWidgetIds = am.getAppWidgetIds(new ComponentName(context, TimerWidgetProvider.class));
		am.updateAppWidget(appWidgetIds, rv);//更新 全部实例
	}
}

AppWidgetProvider中使用的TimerWidgetService

package com.stone.service;

import android.app.Service;
import android.content.Intent;
import android.os.IBinder;

public class TimerWidgetService extends Service {

	@Override
	public IBinder onBind(Intent intent) {
		return null;
	}
	
	@Override
	public void onCreate() {
		super.onCreate();
	}
	
	@Override
	public int onStartCommand(Intent intent, int flags, int startId) {
		/*
		 * do some thing
		 */
		//发送广播通知 widget 更新 状态
		sendBroadcast(new Intent("com.stone.action.start").putExtra("time", System.currentTimeMillis()));
		return Service.START_STICKY;
	}
}