Android 桌面部件

桌面部件是一种利用AppWidget框架将应用程序的某个部件放在桌面。

 res/layout/digitalclock.xml

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/time"
    android:textSize="45px"
    android:textStyle="bold"
    android:textColor="#FFFFFFFF"
    android:background="@drawable/bg"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" />

 res/xml/est_appwidget.xml

<?xml version="1.0" encoding="utf-8"?>
<appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android"
    android:minWidth="146dip"
    android:minHeight="72dip"
    android:updatePeriodMillis="1000"
    android:initialLayout="@layout/digitalclock" />

 AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.studio.android.chp10.ex4"
      android:versionCode="1"
      android:versionName="1.0">
    <application android:icon="@drawable/icon" 
                 android:label="@string/app_name">
        <receiver android:name="ESTTime" 
                  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/est_appwidget" />
        </receiver>
        <service android:name=".ESTTime$UpdateService" />
    </application>
    <uses-sdk android:minSdkVersion="3" />
</manifest> 

 

import android.app.Service;
import android.appwidget.AppWidgetManager;
import android.appwidget.AppWidgetProvider;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.os.IBinder;
import android.text.format.Time;
import android.widget.RemoteViews;

public class ESTTime extends AppWidgetProvider {
    @Override
    public void onUpdate(Context context, 
            AppWidgetManager appWidgetManager,int[] appWidgetIds) {
        context.startService(new Intent(context,UpdateService.class));
    }

    public static class UpdateService extends Service {
        @Override
        public void onStart(Intent intent, int startId) {
            Time estTime = new Time("EST");
            estTime.setToNow();
            //传入所在包包名和布局文件
            RemoteViews updateViews = new RemoteViews(getPackageName(),R.layout.digitalclock);
            updateViews.setTextViewText(R.id.time,
                    estTime.format("%H:%M"));
            
            ComponentName thisWidget = 
                new ComponentName(this, ESTTime.class);
            AppWidgetManager manager = 
                AppWidgetManager.getInstance(this);
            manager.updateAppWidget(thisWidget, updateViews);
        }

        @Override
        public IBinder onBind(Intent intent) {
            return null;
        }
    }
}