关于AppWidgetProvider我就不多说了，这个可以去官方文档看下。

最近因为碰到一个问题，在xml中使用

里面的android：updatePeriodMillis中的更新周期不起作用。首先有几种原因，意思android版本的问题，还有一个是网上都说只能最快30分钟更新一次，不然的话就使用Service进行更新。下面使用两种方法来实现：

一、使用广播来实现

1、既然android：updatePeriodMillis不符合我们的要求，我们可以使用广播的方式来让widget按照我们想要的更新周期来更新。

先来看下AppWidgetProvider.java文件：（准对我的一个备忘录项目：http://blog.csdn.net/moruna/article/details/7895817）

public class AppWidget extends AppWidgetProvider {private DatabaseHelper dbHelper;String[] desk_text;@Overridepublic void onUpdate(Context context, AppWidgetManager appWidgetManager,int[] appWidgetIds) {// TODO Auto-generated method stubsuper.onUpdate(context, appWidgetManager, appWidgetIds);//读取数据库中的记录dbHelper = new DatabaseHelper(context, "ideal.sql");SQLiteDatabase db = dbHelper.getReadableDatabase();Cursor cursor = db.query("user", null, null, null, null, null, null);int desk_num=0;//桌面的便签只显示6条记录desk_text = new String[6];while(cursor.moveToNext()){if(desk_num == 6){break;}String temp_text = cursor.getString(cursor.getColumnIndex("mtext"));//控制每条记录显示的长度if(temp_text.length()>7){temp_text=temp_text.substring(0, 7)+"...";}desk_text[desk_num]=temp_text;System.out.println("desk_text[desk_num]"+desk_text[desk_num]);desk_num++;}db.close();final int Num = appWidgetIds.length;for (int i = 0; i < Num; i++) {int[] mAppWidgetId = appWidgetIds;RemoteViews mRemoteViews = new RemoteViews(context.getPackageName(),R.layout.widget);mRemoteViews.setTextViewText(R.id.desktop_text, array_to_string(desk_text));Intent clickIntent = new Intent(context, NoteActivity.class);PendingIntent pdIntent = PendingIntent.getActivity(context, 0,clickIntent, 0);mRemoteViews.setOnClickPendingIntent(R.id.widget_layout, pdIntent);appWidgetManager.updateAppWidget(mAppWidgetId, mRemoteViews);}}//onReceive方法用来接收广播，以便更新桌面的便签@Overridepublic void onReceive(Context context, Intent intent) {// TODO Auto-generated method stubsuper.onReceive(context, intent);if(intent.getAction().equals("com.ideal.note.widget")){dbHelper = new DatabaseHelper(context, "ideal.sql");SQLiteDatabase db = dbHelper.getReadableDatabase();Cursor cursor = db.query("user", null, null, null, null, null, null);int desk_num=0;desk_text = new String[6];while(cursor.moveToNext()){if(desk_num == 6){break;}String temp_text = cursor.getString(cursor.getColumnIndex("mtext"));if(temp_text.length()>7){temp_text=temp_text.substring(0, 7)+"...";}desk_text[desk_num]=temp_text;System.out.println("desk_text[desk_num]"+desk_text[desk_num]);desk_num++;}db.close();}RemoteViews mRemoteViews = new RemoteViews(context.getPackageName(), R.layout.widget);mRemoteViews.setTextViewText(R.id.desktop_text, array_to_string(desk_text));AppWidgetManager.getInstance(context).updateAppWidget(new ComponentName(context, AppWidget.class), mRemoteViews);}//数组转化为字符显示public String array_to_string(String[] array){String temp_str = "";for(int i=0;i

if(intent.getAction().equals("com.ideal.note.widget"))

Intent mWidgetIntent = new Intent();mWidgetIntent.setAction("com.ideal.note.widget");NoteActivity.this.sendBroadcast(mWidgetIntent);

public class AppWidget extends AppWidgetProvider {private DatabaseHelper dbHelper;String[] desk_text;Handler mHandler;Context mContext;@Overridepublic void onUpdate(Context context, AppWidgetManager appWidgetManager,int[] appWidgetIds) {// TODO Auto-generated method stubsuper.onUpdate(context, appWidgetManager, appWidgetIds);mContext = context;Timer mTimer = new Timer();mTimer.scheduleAtFixedRate(new MyTime(context, appWidgetManager), 1,60000);}private class MyTime extends TimerTask {RemoteViews mRemoteViews;AppWidgetManager mAppWidgetManager;ComponentName thisWidget;public MyTime(Context context, AppWidgetManager appWidgetManager) {this.mAppWidgetManager = appWidgetManager;this.mRemoteViews = new RemoteViews(context.getPackageName(),R.layout.widget);thisWidget = new ComponentName(context, AppWidget.class);}@Overridepublic void run() {// TODO Auto-generated method stubdbHelper = new DatabaseHelper(mContext, "ideal.sql");SQLiteDatabase db = dbHelper.getReadableDatabase();Cursor cursor = db.query("user", null, null, null, null, null, null);int desk_num = 0;desk_text = new String[6];while (cursor.moveToNext()) {if (desk_num == 6) {break;}String temp_text = cursor.getString(cursor.getColumnIndex("mtext"));if (temp_text.length() > 7) {temp_text = temp_text.substring(0, 7) + "...";}desk_text[desk_num] = temp_text;System.out.println("desk_text[desk_num]" + desk_text[desk_num]);desk_num++;}db.close();mRemoteViews.setTextViewText(R.id.desktop_text,array_to_string(desk_text));Intent clickIntent = new Intent(mContext, NoteActivity.class);PendingIntent pdIntent = PendingIntent.getActivity(mContext, 0,clickIntent, 0);mRemoteViews.setOnClickPendingIntent(R.id.widget_layout, pdIntent);mAppWidgetManager.updateAppWidget(thisWidget, mRemoteViews);}}// 数组转化为字符显示public String array_to_string(String[] array) {String temp_str = "";for (int i = 0; i < array.length; i++) {if (array[i] == null) {break;} else {temp_str = temp_str + "\n* " + array[i];}}return temp_str;}}