在AppWidgetProvider源码中可以看到AppWidgetProvider继承了BroadcastReceiver
也就是说widget本身就是个BroadcastReceiver(广播接受者)
AndroidManifest.xml中配置
<receiver android:name="ExampleAppWidgetProvider" > <intent-filter> <action android:name="android.appwidget.action.APPWIDGET_UPDATE" /> </intent-filter> <meta-data android:name="android.appwidget.provider" android:resource="@xml/example_appwidget_info" /> </receiver>
当往窗口添加widget是会发出更新广播
更新广播的名称为"android.appwidget.action.APPWIDGET_UPDATE"
meta-data为组件提供参数
android:name="android.appwidget.provider"为固定的
android:resource="@xml/example_appwidget_info"为widght所采用的界面
example_appwidget_info.xml代码
<?xml version="1.0" encoding="utf-8"?> <appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android" android:minWidth="294dp" android:minHeight="72dp" android:updatePeriodMillis="0" android:initialLayout="@layout/time_appwidget"> </appwidget-provider>
time_appwidget.xml代码
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" android:background="@drawable/rectangle" > <TextView android:layout_width="fill_parent" android:layout_height="fill_parent" android:id="@+id/textView" android:textColor="@android:color/black" android:textSize="20dp" android:text="Just For Test"/> </LinearLayout>
一个简单的wdiget,只有一句话"Just For Test"
接下来改进一下,把文字换成时间
public class TimeWidgetProvider extends AppWidgetProvider { @Override public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) { SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss"); String time = dateFormat.format(System.currentTimeMillis()); RemoteViews remoteView = new RemoteViews(context.getPackageName(), R.layout.time_appwidget); remoteView.setTextViewText(R.id.textView, time); appWidgetManager.updateAppWidget(appWidgetIds[0], remoteView); } }
部署后时间出来了,但是时间是固定的,没有改变,需要加入服务
新建服务
package com.ice.widght; import java.text.SimpleDateFormat; import java.util.Timer; import java.util.TimerTask; import android.app.Service; import android.appwidget.AppWidgetManager; import android.content.ComponentName; import android.content.Intent; import android.os.IBinder; import android.widget.RemoteViews; public class TimeWidgetService extends Service { private Timer timer; @Override public void onCreate() { timer = new Timer(); timer.schedule(new TimeUpdateTask(), 0, 1000); } private class TimeUpdateTask extends TimerTask{ @Override public void run() { SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss"); String time = dateFormat.format(System.currentTimeMillis()); RemoteViews remoteView = new RemoteViews(getPackageName(), R.layout.time_appwidget); remoteView.setTextViewText(R.id.textView, time); AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(getApplicationContext()); appWidgetManager.updateAppWidget( new ComponentName(getApplicationContext(), TimeWidgetProvider.class), remoteView); } } @Override public void onDestroy() { timer.cancel(); timer = null; } @Override public IBinder onBind(Intent arg0) { // TODO Auto-generated method stub return null; } }
TimeWidgetProvider重构代码,负责开启和销毁服务
public class TimeWidgetProvider extends AppWidgetProvider { @Override public void onEnabled(Context context) { context.startService(new Intent(context, TimeWidgetService.class)); } @Override public void onDisabled(Context context) { context.stopService(new Intent(context, TimeWidgetService.class)); } }
完工~~~