Android Widget开发案例(伦敦奥运会倒计时!)

河北衡水武强 3月16日20:21

效果图:
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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:


[img]

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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:
[img]

[/img][img]

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