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:

va] view plain copy


 
<?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: