本文实例讲述了Android桌面组件App Widget用法。分享给大家供大家参考。具体如下：
这里模拟一个案例：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); } }
希望本文所述对大家的Android程序设计有所帮助。