此demo实现 android 桌面控件appwidget
demo：下载地址
MainActivity.java：
package fk.androiddemo_024;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
//app主体ExampleAppWidgetProvider类是一个receiver，在Mainfest中注册
//所以此App只需安装不用启动，即可实现appWidget相应功能
//1，创建appwidget的布局文件example_appwidget.xml
//2，创建xml/example_appwidget_info.xml文件
//3，Mainfest中注册receiver
//4，创建receiver的扩展类AppWidgetProvider的对象(主体)
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
}ExampleAppWidgetProvider.java：
package fk.androiddemo_024;
//AppWidgetProvider实际上是一个扩展的receiver类，参见Mainfest中的注册
//AppWidget的变化，动作都是通过广播发送，然后这里onReceiver来接受处理
//AppWidget的生命周期函数都是AppWidgetProvider中的onReceiver方法调用的
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;
/**
* Implementation of App Widget functionality.
*/
public class ExampleAppWidgetProvider extends AppWidgetProvider {
static String UPDATE_ACTION = "fk.appwidget.UPDATE_APPWIDGET";
static void updateAppWidget(Context context, AppWidgetManager appWidgetManager,
int appWidgetId) {
System.out.println(appWidgetId);
//RemoteViews对象代表appWidget中一系列view对象，但这些对象是运行在别的线程中的
RemoteViews rViews = new RemoteViews(context.getPackageName(), R.layout.example_appwidget);
//appWidget发送广播
Intent intent = new Intent();
intent.setAction(UPDATE_ACTION);
//PendingIntent.getBroadcast得到pIntent启动一个广播，此外还有getActivity和getService
PendingIntent pIntent = PendingIntent.getBroadcast(context, 0, intent, 0);
//rViews代表的对象运行在别的线程（Home Screen）中，用下面的方法绑定监听
//第一个参数是绑定的控件的ID,第二个参数是当控件被点击时，执行pIntent中的Intent
rViews.setOnClickPendingIntent(R.id.but, pIntent);
//appWidget启动一个Activity
Intent intent2=new Intent(context,MainActivity.class);
PendingIntent pIntent2=PendingIntent.getActivity(context, 0, intent2, 0);
rViews.setOnClickPendingIntent(R.id.but2,pIntent2);
//更新appWidget（appWidget的ID，更新内含Intent的rViews）
appWidgetManager.updateAppWidget(appWidgetId,rViews);
}
@Override
//向桌面添加此类appWidget时调用
public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
// There may be multiple widgets active, so update all of them
//循环处理此类所有的appWidget，一种appWidget可以被添加多次
for (int appWidgetId : appWidgetIds) {
updateAppWidget(context, appWidgetManager, appWidgetId);
}
System.out.println("onUpdate");
super.onUpdate(context, appWidgetManager, appWidgetIds);
}
@Override
//第一次向桌面添加此类appWidget时调用
public void onEnabled(Context context) {
System.out.println("onEnabled");
super.onEnabled(context);
// Enter relevant functionality for when the first widget is created
}
@Override
//当最后一个此类appWidget从桌面删除时调用
public void onDisabled(Context context) {
System.out.println("onDisabled");
super.onDisabled(context);
}
@Override
//从桌面删除appWidget时调用
public void onDeleted(Context context, int[] appWidgetIds) {
super.onDeleted(context, appWidgetIds);
System.out.println("onDeleted");
}
@Override
public void onReceive(Context context, Intent intent) {
System.out.println("onReceive");
String action = intent.getAction();
if (action.equals(UPDATE_ACTION)) {
System.out.println("收到");
RemoteViews remoteViews = new RemoteViews(context.getPackageName(), R.layout.example_appwidget);
//更爱appWidget中指定ID控件的text
remoteViews.setTextViewText(R.id.textView, "测试成功");
//得到AppWidgetManager对象
AppWidgetManager manager = AppWidgetManager.getInstance(context);
//得到此类AppWidget的名字
ComponentName name = new ComponentName(context, ExampleAppWidgetProvider.class);
//更新此类AppWidget所有对象
manager.updateAppWidget(name, remoteViews);
}
super.onReceive(context, intent);
}
}<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="fk.androiddemo_024">
<application
android:allowBackup="true"
android:label="风盔"
android:icon="@mipmap/ic_launcher"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<receiver android:name=".ExampleAppWidgetProvider">
<intent-filter>
<action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
<action android:name="fk.appwidget.UPDATE_APPWIDGET" />
</intent-filter>
<meta-data
android:name="android.appwidget.provider"
android:resource="@xml/example_appwidget_info" />
</receiver>
</application>
</manifest>布局activity_main.xml：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="fk.androiddemo_024.MainActivity">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Hello World!" />
</RelativeLayout>布局example_appwidget.xml：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#09C"
android:orientation="vertical">
<TextView
android:id="@+id/textView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:textSize="25dp"
android:text="呱呱" />
<Button
android:id="@+id/but"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="发送广播" />
<Button
android:id="@+id/but2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="打开应用" />
</LinearLayout>定义example_appwidget_info.xml：
<?xml version="1.0" encoding="utf-8"?>
<!--AppWidget的大小以方块为单位,计算公式是(块数*70)–30,非整方块上舍入，下面的大小是2X2大小!-->
<appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android"
android:initialKeyguardLayout="@layout/example_appwidget"
android:initialLayout="@layout/example_appwidget"
android:minHeight="110dp"
android:minWidth="110dp"
android:previewImage="@drawable/example_appwidget_preview"
android:resizeMode="horizontal|vertical"
android:updatePeriodMillis="86400000"
android:widgetCategory="home_screen"></appwidget-provider>运行截图：
