Android进阶教程之----Android Widget开发案例(世界杯倒计时!)

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:

"1.0" encoding="utf-8"?>

    "hello">Hello World, WidetDemo!
    "app_name">DaysToWorldCup

<?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:

"1.0" encoding="utf-8"?>
""
    android:minWidth="50dip"
    android:minHeight="50dip"
    android:updatePeriodMillis="10000"
    android:initialLayout="@layout/main"
/>

<?xml version="1.0" encoding="utf-8"?> <appwidget-provider xmlns: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:

"1.0" encoding="utf-8"?>
""
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@drawable/wordcup"
    >

    android:id="@+id/wordcup"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="@string/hello"
    android:textSize="12px"
    android:textColor="#ff0000"
    />

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns: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);

        }

    }

}

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:

"1.0" encoding="utf-8"?>
""
      package="com.android.tutor"
      android:versionCode="1"
      android:versionName="1.0">
    "@drawable/icon" android:label="@string/app_name">
        ".WidetDemo"
                  android:label="@string/app_name">

                "android.appwidget.action.APPWIDGET_UPDATE" />

            "android.appwidget.provider"
                       android:resource="@xml/widget_provider"
            />


    "7" />

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns: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: