Android之窗口小部件(Widget)详解

xml version&＃61;"1.0" encoding&＃61;"utf-8"?>
<manifest xmlns:android&＃61;"http://schemas.android.com/apk/res/android"package&＃61;"com.skywang.widget"android:versionCode&＃61;"1"android:versionName&＃61;"1.0" ><uses-sdkandroid:minSdkVersion&＃61;"14"android:targetSdkVersion&＃61;"17" /><applicationandroid:allowBackup&＃61;"true"android:icon&＃61;"&＃64;drawable/ic_launcher"android:label&＃61;"&＃64;string/app_name"android:theme&＃61;"&＃64;style/AppTheme" ><receiver android:name&＃61;".ExampleAppWidgetProvider" ><intent-filter><action android:name&＃61;"android.appwidget.action.APPWIDGET_UPDATE" /><action android:name&＃61;"com.skywang.widget.UPDATE_ALL"/>intent-filter><meta-data android:name&＃61;"android.appwidget.provider"android:resource&＃61;"&＃64;xml/example_appwidget_info" />receiver><service android:name&＃61;".ExampleAppWidgetService" ><intent-filter><action android:name&＃61;"android.appwidget.action.EXAMPLE_APP_WIDGET_SERVICE" />intent-filter>service>application>manifest>

<appwidget-provider xmlns:android&＃61;"http://schemas.android.com/apk/res/android"android:minWidth&＃61;"180dp"android:minHeight&＃61;"180dp"android:previewImage&＃61;"&＃64;drawable/preview"android:initialLayout&＃61;"&＃64;layout/example_appwidget"android:resizeMode&＃61;"horizontal|vertical"android:widgetCategory&＃61;"home_screen|keyguard">appwidget-provider>

...
private static final int MIN_UPDATE_PERIOD &＃61; 30 * 60 * 1000; // 30 minutes
...void registerForBroadcastsLocked(Provider p, int[] appWidgetIds) {...// 获取updatePeriodMillis的值long period &＃61; p.info.updatePeriodMillis;// 当updatePeriodMillis小于30分钟时&＃xff0c;设为它为30分钟if (period < MIN_UPDATE_PERIOD) {period &＃61; MIN_UPDATE_PERIOD;} mAlarmManager.setInexactRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP,SystemClock.elapsedRealtime() &＃43; period, period, p.broadcast);...
}

xml version&＃61;"1.0" encoding&＃61;"utf-8"?>
<LinearLayout xmlns:android&＃61;"http://schemas.android.com/apk/res/android"android:layout_width&＃61;"match_parent"android:layout_height&＃61;"match_parent"android:orientation&＃61;"vertical" ><LinearLayout android:layout_width&＃61;"wrap_content" android:layout_height&＃61;"wrap_content"android:layout_gravity&＃61;"center" android:orientation&＃61;"horizontal" ><TextView android:layout_width&＃61;"wrap_content" android:layout_height&＃61;"wrap_content" android:text&＃61;"HomeScreen Widget" /> <Buttonandroid:id&＃61;"&＃64;&＃43;id/btn_show"android:layout_width&＃61;"wrap_content" android:layout_height&＃61;"wrap_content" android:text&＃61;"Show" />LinearLayout> <ImageViewandroid:id&＃61;"&＃64;&＃43;id/iv_show"android:layout_width&＃61;"wrap_content" android:layout_height&＃61;"wrap_content" android:layout_gravity&＃61;"center"/> LinearLayout>

package com.skywang.widget;import android.app.PendingIntent;
import android.appwidget.AppWidgetManager;
import android.appwidget.AppWidgetProvider;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.net.Uri;
import android.widget.RemoteViews;
import android.widget.Toast;
import android.util.Log;import java.util.Set;
import java.util.HashSet;
import java.util.Iterator;/** &＃64;author : skywang * description : 提供App Widget*/public class ExampleAppWidgetProvider extends AppWidgetProvider {private static final String TAG &＃61; "ExampleAppWidgetProvider";private boolean DEBUG &＃61; false; // 启动ExampleAppWidgetService服务对应的actionprivate final Intent EXAMPLE_SERVICE_INTENT &＃61; new Intent("android.appwidget.action.EXAMPLE_APP_WIDGET_SERVICE");// 更新 widget 的广播对应的actionprivate final String ACTION_UPDATE_ALL &＃61; "com.skywang.widget.UPDATE_ALL";// 保存 widget 的id的HashSet&＃xff0c;每新建一个 widget 都会为该 widget 分配一个 id。private static Set idsSet &＃61; new HashSet();// 按钮信息private static final int BUTTON_SHOW &＃61; 1;// 图片数组private static final int[] ARR_IMAGES &＃61; { R.drawable.sample_0, R.drawable.sample_1, R.drawable.sample_2, R.drawable.sample_3, R.drawable.sample_4, R.drawable.sample_5,R.drawable.sample_6,R.drawable.sample_7,};// onUpdate() 在更新 widget 时&＃xff0c;被执行&＃xff0c;
&＃64;Overridepublic void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {Log.d(TAG, "onUpdate(): appWidgetIds.length&＃61;"&＃43;appWidgetIds.length);// 每次 widget 被创建时&＃xff0c;对应的将widget的id添加到set中for (int appWidgetId : appWidgetIds) {idsSet.add(Integer.valueOf(appWidgetId));}prtSet();}// 当 widget 被初次添加 或者 当 widget 的大小被改变时&＃xff0c;被调用
&＃64;Override public void onAppWidgetOptionsChanged(Context context, AppWidgetManager appWidgetManager, int appWidgetId, Bundle newOptions) {Log.d(TAG, "onAppWidgetOptionsChanged");super.onAppWidgetOptionsChanged(context, appWidgetManager, appWidgetId, newOptions); } // widget被删除时调用
&＃64;Override public void onDeleted(Context context, int[] appWidgetIds) { Log.d(TAG, "onDeleted(): appWidgetIds.length&＃61;"&＃43;appWidgetIds.length);// 当 widget 被删除时&＃xff0c;对应的删除set中保存的widget的idfor (int appWidgetId : appWidgetIds) {idsSet.remove(Integer.valueOf(appWidgetId));}prtSet();super.onDeleted(context, appWidgetIds); }// 第一个widget被创建时调用
&＃64;Override public void onEnabled(Context context) { Log.d(TAG, "onEnabled");// 在第一个 widget 被创建时&＃xff0c;开启服务
context.startService(EXAMPLE_SERVICE_INTENT);super.onEnabled(context); } // 最后一个widget被删除时调用
&＃64;Override public void onDisabled(Context context) { Log.d(TAG, "onDisabled");// 在最后一个 widget 被删除时&＃xff0c;终止服务
context.stopService(EXAMPLE_SERVICE_INTENT);super.onDisabled(context); }// 接收广播的回调函数
&＃64;Override public void onReceive(Context context, Intent intent) { final String action &＃61; intent.getAction();Log.d(TAG, "OnReceive:Action: " &＃43; action);if (ACTION_UPDATE_ALL.equals(action)) {// “更新”广播
updateAllAppWidgets(context, AppWidgetManager.getInstance(context), idsSet);} else if (intent.hasCategory(Intent.CATEGORY_ALTERNATIVE)) {// “按钮点击”广播Uri data &＃61; intent.getData();int buttonId &＃61; Integer.parseInt(data.getSchemeSpecificPart());if (buttonId &＃61;&＃61; BUTTON_SHOW) {Log.d(TAG, "Button wifi clicked");Toast.makeText(context, "Button Clicked", Toast.LENGTH_SHORT).show();}}super.onReceive(context, intent); } // 更新所有的 widget private void updateAllAppWidgets(Context context, AppWidgetManager appWidgetManager, Set set) {Log.d(TAG, "updateAllAppWidgets(): size&＃61;"&＃43;set.size());// widget 的idint appID;// 迭代器&＃xff0c;用于遍历所有保存的widget的idIterator it &＃61; set.iterator();while (it.hasNext()) {appID &＃61; ((Integer)it.next()).intValue(); // 随机获取一张图片int index &＃61; (new java.util.Random().nextInt(ARR_IMAGES.length));if (DEBUG) Log.d(TAG, "onUpdate(): index&＃61;"&＃43;index); // 获取 example_appwidget.xml 对应的RemoteViews RemoteViews remoteView &＃61; new RemoteViews(context.getPackageName(), R.layout.example_appwidget);// 设置显示图片
remoteView.setImageViewResource(R.id.iv_show, ARR_IMAGES[index]);// 设置点击按钮对应的PendingIntent&＃xff1a;即点击按钮时&＃xff0c;发送广播。
remoteView.setOnClickPendingIntent(R.id.btn_show, getPendingIntent(context,BUTTON_SHOW));// 更新 widget
appWidgetManager.updateAppWidget(appID, remoteView); } }private PendingIntent getPendingIntent(Context context, int buttonId) {Intent intent &＃61; new Intent();intent.setClass(context, ExampleAppWidgetProvider.class);intent.addCategory(Intent.CATEGORY_ALTERNATIVE);intent.setData(Uri.parse("custom:" &＃43; buttonId));PendingIntent pi &＃61; PendingIntent.getBroadcast(context, 0, intent, 0 );return pi;}// 调试用&＃xff1a;遍历setprivate void prtSet() {if (DEBUG) {int index &＃61; 0;int size &＃61; idsSet.size();Iterator it &＃61; idsSet.iterator();Log.d(TAG, "total:"&＃43;size);while (it.hasNext()) {Log.d(TAG, index &＃43; " -- " &＃43; ((Integer)it.next()).intValue());}}}
}

package com.skywang.widget;import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.os.IBinder;
import android.util.Log;/** &＃64;author : skywang * description : 周期性更新AppWidget的服务*/public class ExampleAppWidgetService extends Service {private static final String TAG&＃61;"ExampleAppWidgetService"; // 更新 widget 的广播对应的actionprivate final String ACTION_UPDATE_ALL &＃61; "com.skywang.widget.UPDATE_ALL";// 周期性更新 widget 的周期private static final int UPDATE_TIME &＃61; 5000;// 周期性更新 widget 的线程private UpdateThread mUpdateThread;private Context mContext;// 更新周期的计数private int count&＃61;0; &＃64;Overridepublic void onCreate() {// 创建并开启线程UpdateThreadmUpdateThread &＃61; new UpdateThread();mUpdateThread.start();mContext &＃61; this.getApplicationContext();super.onCreate();}&＃64;Overridepublic void onDestroy(){// 中断线程&＃xff0c;即结束线程。if (mUpdateThread !&＃61; null) {mUpdateThread.interrupt();}super.onDestroy();}&＃64;Overridepublic IBinder onBind(Intent intent) {return null;}/** 服务开始时&＃xff0c;即调用startService()时&＃xff0c;onStartCommand()被执行。*/&＃64;Overridepublic int onStartCommand(Intent intent, int flags, int startId) {Log.d(TAG, "onStartCommand"); super.onStartCommand(intent, flags, startId);return START_STICKY;}private class UpdateThread extends Thread {&＃64;Overridepublic void run() {super.run();try {count &＃61; 0;while (true) {Log.d(TAG, "run ... count:"&＃43;count);count&＃43;&＃43;;Intent updateIntent&＃61;new Intent(ACTION_UPDATE_ALL);mContext.sendBroadcast(updateIntent);Thread.sleep(UPDATE_TIME);} } catch (InterruptedException e) {// 将 InterruptedException 定义在while循环之外&＃xff0c;意味着抛出 InterruptedException 异常时&＃xff0c;终止线程。
e.printStackTrace();}}}
}