<appwidget-provider
 xmlns:android="http://schemas.android.com/apk/res/android"
 android:minHeight="72dp"
 android:minWidth="294dp"
 android:updatePeriodMillis="86400000"
 android:initialLayout="@layout/example_widget"
 >
</appwidget-provider>

<?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="vertical" >

 <TextView
  android:id="@+id/textview1"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:text="MyFirst Widget Example!"
  >
 </TextView>
 <!--由于只是实现简单的效果，所以就只用一个TextView吧-->
</LinearLayout>

package com.summer.widgettest;

import android.appwidget.AppWidgetManager;
import android.appwidget.AppWidgetProvider;
import android.content.Context;
/**
*在这四个必须的方法中，只是打印出一句话，来观察其“生命周期”即可
*/
public class Widget extends AppWidgetProvider {

 @Override
public void onUpdate(Context context, AppWidgetManager appWidgetManager,
  int[] appWidgetIds) {
 // TODO Auto-generated method stub
  System.out.println("onUpdate");
 super.onUpdate(context, appWidgetManager, appWidgetIds);
}

 @Override
 public void onDeleted(Context context, int[] appWidgetIds) {
  // TODO Auto-generated method stub
  System.out.println("onDeleted");
  super.onDeleted(context, appWidgetIds);
 }

 @Override
 public void onDisabled(Context context) {
  // TODO Auto-generated method stub
  System.out.println("onDisabled");
  super.onDisabled(context);
 }

 @Override
 public void onEnabled(Context context) {
  // TODO Auto-generated method stub
  System.out.println("onEnabled");
  super.onEnabled(context);
 }

}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
 package="com.summer.widgettest"
 android:versionCode="1"
 android:versionName="1.0" >

 <uses-sdk
  android:minSdkVersion="8"
  android:targetSdkVersion="18" />

 <application
  android:allowBackup="true"
  android:icon="@drawable/ic_launcher"
  android:label="@string/app_name"
  android:theme="@style/AppTheme" >
  <activity
   android:name="com.summer.widgettest.MainActivity"
   android:label="@string/app_name" >
   <intent-filter>
    <action android:name="android.intent.action.MAIN" />

    <category android:name="android.intent.category.LAUNCHER" />
   </intent-filter>
  </activity>

  <receiver android:name="com.summer.widgettest.Widget">
   <intent-filter >
    <action android:name="android.appwidget.action.APPWIDGET_UPDATE"/>
   </intent-filter>
   <meta-data android:name="android.appwidget.provider"
    android:resource="@xml/appwidget_info"/>
  </receiver>
 </application>

</manifest>

 <Button 
  android:id="@+id/button1"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:text="Click To Renew!"
  >
 </Button>

 @Override
public void onUpdate(Context context, AppWidgetManager appWidgetManager,
  int[] appWidgetIds) {
 // TODO Auto-generated method stub
  System.out.println("onUpdate");

  for(int i=0;i<appWidgetIds.length;i++){
   //check which appwidget is enabled!
   System.out.println(appWidgetIds[i]);
   Intent intent=new Intent(context,RenewActivity.class);
   PendingIntent pendingIntent=PendingIntent.getActivity(context, 0, intent, 0);

   RemoteViews remoteViews=new RemoteViews(context.getPackageName(), R.layout.example_widget);
   remoteViews.setOnClickPendingIntent(R.id.button1, pendingIntent);
   appWidgetManager.updateAppWidget(appWidgetIds[i], remoteViews);
  }

 super.onUpdate(context, appWidgetManager, appWidgetIds);
}


RenewActivity.java

package com.summer.widgettest;

import android.app.Activity;
import android.os.Bundle;

public class RenewActivity extends Activity{

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  // TODO Auto-generated method stub
  super.onCreate(savedInstanceState);
  setContentView(R.layout.renew);
 }
 //由于renew布局是一个非常简单的界面（一个TextView而已），所以不再贴出代码
}

<activity 
   android:name="com.summer.widgettest.RenewActivity"
   android:label="Renew Activity!"
   >
</activity>