为App添加桌面小部件

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简述

Android弱化了线程和进程等概念，主要表现为组件。这个桌面小部件与App是分离的，可以通过服务或广播来通信。

1.在启动的Activity里加

    <intent-filter>
        <action android:name="android.appwidget.action.APPWIDGET_CONFIGURE"/>
    </intent-filter>

2. 定义一个部件组件（改自官网文档）

public class MyAppWidget extends AppWidgetProvider {
    public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
        final int N = appWidgetIds.length;
        // Perform this loop procedure for each App Widget that belongs to this provider
        for (int i=0; i<N; i++) {
            int appWidgetId = appWidgetIds[i];
            // 创建Intent来启动Acitivity
            Intent intent = new Intent(context, MainActivity.class);
            PendingIntent pendingIntent = PendingIntent.getActivity(context, 0, intent, 0);
            // Get the layout for the App Widget and attach an on-click listener
            // to the button
            // 初始化部件布局，设置监听事件
            RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.appwidget_provider_layout);
            views.setOnClickPendingIntent(R.id.button, pendingIntent);
            // Tell the AppWidgetManager to perform an update on the current app widget
            appWidgetManager.updateAppWidget(appWidgetId, views);
        }
    }
}

3. 写好布局 R.layout.appwidget_provider_layout

我只加了个按钮

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <Button
        android:id="@+id/button"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:text="OK" />
</LinearLayout>

4. res里新建一个xml文件夹，添加配置

<?xml version="1.0" encoding="utf-8"?>
<appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android"
    android:minWidth="200dip"
    android:minHeight="50dip"
    android:initialLayout="@layout/appwidget_provider_layout" >
</appwidget-provider>

5. 在AndroidManifest.xml注册

    <receiver android:name="MyAppWidget"  android:label="测试插件" >
        <intent-filter>
            <action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
        </intent-filter>
        <meta-data android:name="android.appwidget.provider"
            android:resource="@xml/my_provider" />
    </receiver>

6. 完成

http://androiddoc.qiniudn.com/guide/topics/appwidgets/index.html