android widget使用

在 \res\xml下新建example_appwidget_info.xml

<?xml version="1.0" encoding="utf-8"?><appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android"    android:initialLayout="@layout/process_widget"    android:minHeight="72.0dip"    android:minWidth="294.0dip"    android:updatePeriodMillis="0" />

在layout下新建process_widget.xml,用来显示widget的布局

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="wrap_content"    android:src="@drawable/widget_bg_portrait"    android:gravity="center_vertical" >    <LinearLayout        android:layout_width="0.0dip"        android:layout_height="fill_parent"        android:layout_marginLeft="5.0dip"        android:layout_weight="1.0"        android:background="@drawable/widget_bg_portrait_child"        android:gravity="center_vertical"        android:orientation="vertical"        android:paddingBottom="3.0dip"        android:paddingTop="3.0dip" >        <TextView            android:id="@+id/process_count"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_marginLeft="10.0dip"            />        <ImageView            android:layout_width="fill_parent"            android:layout_height="wrap_content"            android:layout_marginBottom="1.0dip"            android:layout_marginTop="1.0dip"            android:background="@drawable/widget_bg_portrait_child_divider" />        <TextView            android:id="@+id/process_memory"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_marginLeft="10.0dip"          />    </LinearLayout>    <LinearLayout        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:gravity="center_horizontal"        android:orientation="vertical" >        <LinearLayout            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:gravity="center_vertical" >            <ImageView                android:layout_width="20.0dip"                android:layout_height="20.0dip"                android:background="@drawable/notification" />            <TextView                android:layout_width="wrap_content"                android:layout_height="wrap_content"                android:text="@string/app_name"                />        </LinearLayout>        <Button            android:id="@+id/btn_clear"            android:layout_width="90.0dip"            android:layout_height="wrap_content"            android:layout_centerVertical="true"            android:layout_marginTop="5.0dip"            android:background="@drawable/button_background_selected"            android:text="一键清理"            />    </LinearLayout></LinearLayout>

新建一个类ProcessWidget继承AppWidgetProvider

import cn.itcast.mobilesafe.service.UpdateWidgetService;import android.appwidget.AppWidgetProvider;import android.content.Context;import android.content.Intent;import android.sax.StartElementListener;public class ProcessWidget extends AppWidgetProvider {Intent intent;@Overridepublic void onDeleted(Context context, int[] appWidgetIds) {super.onDeleted(context, appWidgetIds);intent = new Intent(context,UpdateWidgetService.class);context.stopService(intent);}@Overridepublic void onEnabled(Context context) {super.onEnabled(context);intent = new Intent(context,UpdateWidgetService.class);context.startService(intent);}}

新建类UpdateWidgetService实现widget更新

import android.app.PendingIntent;import android.app.Service;import android.appwidget.AppWidgetManager;import android.content.ComponentName;import android.content.Intent;import android.graphics.Color;import android.os.IBinder;import android.widget.RemoteViews;public class UpdateWidgetService extends Service {private Timer timer ;private TimerTask task;private AppWidgetManager  widgetmanager;@Overridepublic IBinder onBind(Intent intent) {// TODO Auto-generated method stubreturn null;}@Overridepublic void onCreate() {timer = new Timer();widgetmanager =  AppWidgetManager.getInstance(getApplicationContext());task = new TimerTask() {@Overridepublic void run() {// 更新widget的界面ComponentName name = new ComponentName("cn.itcast.mobilesafe", "cn.itcast.mobilesafe.receiver.ProcessWidget");RemoteViews views = new RemoteViews("cn.itcast.mobilesafe", R.layout.process_widget);views.setTextViewText(R.id.process_count, "进程数目"+TaskUtil.getProcessCount(getApplicationContext()));views.setTextColor(R.id.process_count, Color.RED);views.setTextViewText(R.id.process_memory, "可用内存"+TaskUtil.getMemeorySize(getApplicationContext()));views.setTextColor(R.id.process_memory, Color.RED);Intent intent = new Intent(UpdateWidgetService.this,LockScreenReceiver.class);PendingIntent pendingIntent = PendingIntent.getBroadcast(getApplicationContext(), 0, intent, 0);views.setOnClickPendingIntent(R.id.btn_clear, pendingIntent);widgetmanager.updateAppWidget(name, views);}};timer.scheduleAtFixedRate(task, 1000, 2000);super.onCreate();}@Overridepublic void onDestroy() {timer.cancel();timer = null;task =null;super.onDestroy();}}

TaskUtil的代码如下：

import java.util.List;import android.app.ActivityManager;import android.app.ActivityManager.MemoryInfo;import android.app.ActivityManager.RunningAppProcessInfo;import android.content.Context;import android.text.TextUtils;public class TaskUtil {public static void killAllProcess(Context context) {ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);List<RunningAppProcessInfo> runningapps = am.getRunningAppProcesses();for (RunningAppProcessInfo info : runningapps) {String packname = info.processName;am.killBackgroundProcesses(packname);}}public static int getProcessCount(Context context) {ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);List<RunningAppProcessInfo> runningapps = am.getRunningAppProcesses();return runningapps.size();}public static String getMemeorySize(Context context) {ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);MemoryInfo outInfo = new ActivityManager.MemoryInfo();am.getMemoryInfo(outInfo);return TextFormater.getDataSize( outInfo.availMem);}}

在AndroidManifest.xml的配置

 <receiver android:name=".ProcessWidget" >    <intent-filter>        <action android:name="android.appwidget.action.APPWIDGET_UPDATE" />    </intent-filter>    <meta-data android:name="android.appwidget.provider"               android:resource="@xml/example_appwidget_info" /></receiver>