appwidget 窗口小部件学习笔记

接了个模块，做便签，所以在学习便签的过程成也对窗口小部件小有收获，分享之：

 

Widget大小的计算 :(单元格数*74)-2，API上说是为了防止像素计算时的整数舍入导致错所以-2...不是很明白

 

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关机在开机后，会刷新桌面上的所有widget，调用其AppWidgetProvider的onReceive->onUpdate->onReceive方法

故必须在 AppWidgetProvider中，处理及面的刷新时，RemoteView内容的显示，或者onclick事件的响应。

生成一个新的小部件的时候的Id分配

Bundle extras = intent.getExtras();  if (extras != null) {           mAppWidgetId = extras.getInt(AppWidgetManager.EXTRA_APPWIDGET_ID,                 AppWidgetManager.INVALID_APPWIDGET_ID); }                                 // If they gave us an intent without the widget id, just bail.  if (mAppWidgetId == AppWidgetManager.INVALID_APPWIDGET_ID) {          finish(); }

 

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获取当前provider在桌面上显示的所有小部件的id值

 

Bundle extras = intent.getExtras();             if (extras != null) {                 int[] appWidgetIds = extras.getIntArray(AppWidgetManager.EXTRA_APPWIDGET_IDS);                 if (appWidgetIds != null && appWidgetIds.length > 0) {                     this.onUpdate(context, AppWidgetManager.getInstance(context), appWidgetIds);                 }             }

 

 

AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(context);

int[] appWidgetIds=appWidgetManager.getAppWidgetIds(new  ComponentName(this, myWidgetProviderLarge.class));

 

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可以在RemoveView中布局的控件，必须在其类上做@RemoteView声明

如源码中的 TextView：

@RemoteView public class TextView extends View implements ViewTreeObserver.OnPreDrawListener {...}

 

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如果生成多个内容不同的桌面小部件，并且使其可响应点击事件，打开响应id对应的内容，则需记录每个小部件的appwidgetId，并将其发送给点击事件相应的activity。

如当前activity为小部件的配置活动，点击打开EditWidget.java：

                Intent configIntent = new Intent(this, EditWidget.class);                            configIntent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, mAppWidgetId);                                configIntent.setAction(uri.toString());                 PendingIntent pendingIntent = PendingIntent.getActivity(EditNote.this, 0,configIntent, 0);                 views.setOnClickPendingIntent(R.id.note_appwidget, pendingIntent);                                 AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(EditNote.this);                 appWidgetManager.updateAppWidget(mAppWidgetId, views);

 

点击后打开EditWidget.java

        Intent t = getIntent();            Log.i("", "this is ===="+t.getAction());         mAppWidgetId = t.getExtras().getInt(AppWidgetManager.EXTRA_APPWIDGET_ID, -1);         Log.i("", "this is  [" + mAppWidgetId + "] editing!");