Android之桌面组件App Widget案例

模拟一个案例：把AppWidget添加到桌面后，点击AppWidget后AppWidget文本会轮回改变

main.xml布局文件

  

   <?
   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
   "
   >
   
 
   <
   TextView android:id
   =
   "
   @+id/tv
   "
   
 android:layout_width
   =
   "
   fill_parent
   "
   
 android:layout_height
   =
   "
   wrap_content
   "
    
 android:text
   =
   "
   程序入口
   "
    
 android:textSize
   =
   "
   50dip
   "
   />
   

   </
   LinearLayout
   >
  

res/xml/my_appwidget.xml布局文件

  

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

   <
   appwidget
   -
   provider
 xmlns:android
   =
   "
   http://schemas.android.com/apk/res/android
   "
   
 android:minWidth
   =
   "
   120dp
   "
    
 android:minHeight
   =
   "
   60dp
   "
   
 android:updatePeriodMillis
   =
   "
   1000
   "
   
 android:initialLayout
   =
   "
   @layout/main
   "
   >
   

   </
   appwidget
   -
   provider
   >
  

清单文件

  

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

   <
   manifest xmlns:android
   =
   "
   http://schemas.android.com/apk/res/android
   "
   
 
   package
   =
   "
   com.ljq.activity
   "
    android:versionCode
   =
   "
   1
   "
   
 android:versionName
   =
   "
   1.0
   "
   >
   
 
   <
   application android:icon
   =
   "
   @drawable/icon
   "
   
 android:label
   =
   "
   @string/app_name
   "
   >
   
 
   <
   receiver android:name
   =
   "
   .TestActivity
   "
   >
   
 
   <
   meta
   -
   data android:name
   =
   "
   android.appwidget.provider
   "
   
 android:resource
   =
   "
   @xml/my_appwidget
   "
   >
   
 
   </
   meta
   -
   data
   >
   
 
   <
   intent
   -
   filter
   >
   
 
   <
   action android:name
   =
   "
   COM.LJQ.ACTION.WIDGET.CLICK
   "
   ></
   action
   >
   
 
   <
   action android:name
   =
   "
   android.appwidget.action.APPWIDGET_UPDATE
   "
    
   />
   
 
   </
   intent
   -
   filter
   >
   
 
   </
   receiver
   >
   
 
   </
   application
   >
   
 
   <
   uses
   -
   sdk android:minSdkVersion
   =
   "
   7
   "
    
   />
   


   </
   manifest
   >
  

变量类UtilTool：用来控件文本改变

  

   package
    com.ljq.activity;



   public
    
   class
    UtilTool {
 
   public
    
   static
    
   boolean
    isChange
   =
   true
   ;
}
  

TestActivity类，继承自AppWidgetProvider

  

   package
    com.ljq.activity;


   import
    android.app.PendingIntent;

   import
    android.appwidget.AppWidgetManager;

   import
    android.appwidget.AppWidgetProvider;

   import
    android.content.ComponentName;

   import
    android.content.Context;

   import
    android.content.Intent;

   import
    android.widget.RemoteViews;


   public
    
   class
    TestActivity 
   extends
    AppWidgetProvider {
 
   //
    自定义一个Action名
   

    
   private
    
   static
    
   final
    String ACTION_CLICK_NAME 
   =
    
   "
   COM.LJQ.ACTION.WIDGET.CLICK
   "
   ;
 
   private
    RemoteViews rv;

 @Override
 
   public
    
   void
    onUpdate(Context context, AppWidgetManager appWidgetManager, 
   int
   [] appWidgetIds) {
 System.out.println(
   "
   onUpdate
   "
   );
 
   //
   获取R.layout.main布局，通过类RemoteViews对布局R.layout.main里的控件进行操作
   

    
   /*
   rv = new RemoteViews(context.getPackageName(), R.layout.main);
 Intent intentClick = new Intent(ACTION_CLICK_NAME);
 PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, intentClick, 0);
 rv.setOnClickPendingIntent(R.id.tv, pendingIntent);
 
 ComponentName cmp = new ComponentName(context, TestActivity.class);
 AppWidgetManager myAppWidgetManager = AppWidgetManager.getInstance(context);
 myAppWidgetManager.updateAppWidget(cmp, rv);
   */
   
 
   final
    
   int
    N 
   =
    appWidgetIds.length;
 
   for
    (
   int
    i 
   =
    
   0
   ; i 
   <
    N; i
   ++
   ) {
 
   int
    appWidgetId 
   =
    appWidgetIds[i];
 updateAppWidget(context, appWidgetManager, appWidgetId);
 }
 
 }
 
 
   //
   AppWidget生命周期: 每接收一次，广播执行一次为一个生命周期结束。
 
   //
   也就是说在重写AppWidgetProvider类里面声明全局变量做状态判断，
 
   //
   每次状态改变AppWidgetProvider再接收第二次广播时即为你重新初始化也就是说重新实例化了一次AppWidgetProvider。
 
   //
   今天我因为在里面放了一个boolean值初始化为true，观察调试看到每次进入都为TRUE故你在设置桌面组件时，
 
   //
   全局变量把它声明在另外一个实体类用来判断是没问题的，切忌放在本类。
   

    @Override
 
   public
    
   void
    onReceive(Context context, Intent intent) {
 System.out.println(
   "
   onReceive
   "
   );
 
   if
    (rv 
   ==
    
   null
   ) {
 rv 
   =
    
   new
    RemoteViews(context.getPackageName(), R.layout.main);
 }
 
   if
    (intent.getAction().equals(ACTION_CLICK_NAME)) {
 
   if
    (UtilTool.isChange) {
 rv.setTextViewText(R.id.tv, 
   "
   abc
   "
   );
 } 
   else
    {
 rv.setTextViewText(R.id.tv, 
   "
   123
   "
   );
 }
 UtilTool.isChange 
   =
    
   !
   UtilTool.isChange;
 AppWidgetManager appWidgetManger 
   =
    AppWidgetManager.getInstance(context);
 
   int
   [] appIds 
   =
    appWidgetManger.getAppWidgetIds(
   new
    ComponentName(context, TestActivity.
   class
   ));
 appWidgetManger.updateAppWidget(appIds, rv);
 }
   else
   {
 
   super
   .onReceive(context, intent);
 }
 
 }
 
 
   private
    
   void
    updateAppWidget(Context context,
 AppWidgetManager appWidgeManger, 
   int
    appWidgetId) {
 rv 
   =
    
   new
    RemoteViews(context.getPackageName(), R.layout.main);
 Intent intentClick 
   =
    
   new
    Intent();
 intentClick.setAction(ACTION_CLICK_NAME);
 PendingIntent pendingIntent 
   =
    PendingIntent.getBroadcast(context, 
   0
   , intentClick, 
   0
   );
 rv.setOnClickPendingIntent(R.id.tv, pendingIntent);
 appWidgeManger.updateAppWidget(appWidgetId, rv);
 }

}