Android高手进阶教程(八)之----Android Widget开发案例(世界杯倒计时!)

今天我们要写一下Android Widget的开发，由于快点凌晨，我就不说的太具体了，同志们就模仿吧！首先看一下效果图:

下面是Demo的详细步骤:

一、新建一个Android工程命名为:WidgetDemo.

二、准备素材，一个是Widget的图标，一个是Widget的背景。存放目录如下图:

三、修改string.xml文件如下:

 <?xml version="1.0" encoding="utf-8"?>   <resources>       <string name="hello">Hello World, WidetDemo!</string>       <string name="app_name">DaysToWorldCup</string>   </resources>

四、建立Widget内容提供者文件，我们在res下建立xml文件夹，并且新建一个widget_provider.xml代码入下:

 <?xml version="1.0" encoding="utf-8"?>   <appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android"      android:minWidth="50dip"      android:minHeight="50dip"      android:updatePeriodMillis="10000"      android:initialLayout="@layout/main"  />

五、修改main.xml布局，代码如下:

 <?xml version="1.0" encoding="utf-8"?>   <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"      android:orientation="vertical"      android:layout_width="fill_parent"      android:layout_height="fill_parent"      android:background="@drawable/wordcup"      >   <TextView         android:id="@+id/wordcup"      android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:text="@string/hello"      android:textSize="12px"      android:textColor="#ff0000"      />   </LinearLayout>

六、修改WidgetDemo.java代码如下:

 package com.android.tutor;   import java.util.Calendar;   import java.util.Date;   import java.util.GregorianCalendar;   import java.util.Timer;   import java.util.TimerTask;   import android.appwidget.AppWidgetManager;   import android.appwidget.AppWidgetProvider;   import android.content.ComponentName;   import android.content.Context;   import android.widget.RemoteViews;   public class WidetDemo extends AppWidgetProvider {       /** Called when the activity is first created. */           @Override      public void onUpdate(Context context, AppWidgetManager appWidgetManager,               int[] appWidgetIds) {                      Timer timer = new Timer();           timer.scheduleAtFixedRate(new MyTime(context,appWidgetManager), 1, 60000);           super.onUpdate(context, appWidgetManager, appWidgetIds);       }                     private class MyTime extends TimerTask{           RemoteViews remoteViews;           AppWidgetManager appWidgetManager;           ComponentName thisWidget;                      public MyTime(Context context,AppWidgetManager appWidgetManager){               this.appWidgetManager = appWidgetManager;               remoteViews = new RemoteViews(context.getPackageName(),R.layout.main);                              thisWidget = new ComponentName(context,WidetDemo.class);           }           public void run() {                              Date date = new Date();               Calendar calendar = new GregorianCalendar(2010,06,11);               long days = (((calendar.getTimeInMillis()-date.getTime())/1000))/86400;               remoteViews.setTextViewText(R.id.wordcup, "距离南非世界杯还有" + days+"天");               appWidgetManager.updateAppWidget(thisWidget, remoteViews);                          }                  }        }

七、修改配置文件AndroidManifest.xml，代码如下:

 <?xml version="1.0" encoding="utf-8"?>   <manifest xmlns:android="http://schemas.android.com/apk/res/android"        package="com.android.tutor"        android:versionCode="1"        android:versionName="1.0">       <application android:icon="@drawable/icon" android:label="@string/app_name">           <receiver android:name=".WidetDemo"                    android:label="@string/app_name">               <intent-filter>                   <action android:name="android.appwidget.action.APPWIDGET_UPDATE" />               </intent-filter>               <meta-data android:name="android.appwidget.provider"                         android:resource="@xml/widget_provider"              />           </receiver>       </application>       <uses-sdk android:minSdkVersion="7" />   </manifest>

八、点击运行(Ctrl+F11),之，运行成功后，我们长时间点击桌面，会出现如下俩个，依次点击，就可以看到最上面的效果图: