我对 android 开发很陌生,我想为我的应用程序创建一个小部件。不幸的是,我无法让它工作。我希望我的小部件启动服务。该服务应包含所有逻辑,例如根据内部存储文件的数据读取更新文本字段。我必须每分钟更新一次我的小部件,因为我想显示剩余时间。为此,我想到了一个 AlarmManager。
我以此作为参考: http ://www.helloandroid.com/tutorials/mastering-android-widget-development-part4
这是我到目前为止所尝试的:AppWidgetProvider:
public class WidgetCtrl extends AppWidgetProvider {
public static String WIDGET_UPDATE = "WIDGET_UPDATE";
public static int UPDATE_RATE = 60 * 1000;
private SessionData sessionData = SessionData.getInstance();
private BaseCtrl baseCtrl = BaseCtrl.getInstance();
@Override
public void onUpdate(Context context, AppWidgetManager appWidgetManager,
int[] appWidgetIds) {
// Service Intent
Intent serviceIntent = new Intent(context, UpdateWidgetService.class);
serviceIntent.setAction(UpdateWidgetService.UPDATE);
PendingIntent servicePendingIntent = PendingIntent.getService(context,
0, serviceIntent, 0);
// send Service intent
try {
servicePendingIntent.send();
} catch (CanceledException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
// start alarm manager for all widget instances
for (int appWidgetId : appWidgetIds) {
setAlarm(context, appWidgetId, UPDATE_RATE);
}
super.onUpdate(context, appWidgetManager, appWidgetIds);
}
@Override
public void onReceive(Context context, Intent intent) {
if (WIDGET_UPDATE.equals(intent.getAction())) {
Toast.makeText(context, "onReceiver()", Toast.LENGTH_LONG).show();
}
super.onReceive(context, intent);
}
@Override
public void onDisabled(Context context) {
context.stopService(new Intent(context, UpdateWidgetService.class));
super.onDisabled(context);
}
public static void setAlarm(Context context, int appWidgetId, int updateRate) {
Intent serviceIntent = new Intent(context, UpdateWidgetService.class);
serviceIntent.setAction(UpdateWidgetService.UPDATE);
PendingIntent servicePendingIntent = PendingIntent.getService(context,
0, serviceIntent, 0);
AlarmManager alarms = (AlarmManager) context
.getSystemService(Context.ALARM_SERVICE);
if (updateRate >= 0) {
alarms.setRepeating(AlarmManager.ELAPSED_REALTIME,
SystemClock.elapsedRealtime(), updateRate, servicePendingIntent);
} else {
// on a negative updateRate stop the refreshing
alarms.cancel(servicePendingIntent);
}
}
}
服务:
public class UpdateWidgetService extends Service {
public static String UPDATE = "update";
private SessionData sessionData = SessionData.getInstance();
private BaseCtrl baseCtrl = BaseCtrl.getInstance();
private Context ctx;
@Override
public void onStart(Intent intent, int startId) {
ctx = getApplicationContext();
int appWidgetId = intent.getExtras().getInt(
AppWidgetManager.EXTRA_APPWIDGET_ID);
// TODO update information and display
AppWidgetManager appWidgetManger = AppWidgetManager.getInstance(ctx);
int[] allWidgetIds = intent.getIntArrayExtra(AppWidgetManager.EXTRA_APPWIDGET_IDS);
ComponentName currWidget = new ComponentName(ctx, WidgetCtrl.class);
RemoteViews remoteViews = new RemoteViews(ctx.getPackageName(), R.layout.widget);
remoteViews.setTextViewText(R.id.widget_text, "test");
final Intent updateIntent = new Intent(ctx, UpdateWidgetService.class);
final PendingIntent pending = PendingIntent.getService(ctx, 0, updateIntent, 0);
final AlarmManager alarm = (AlarmManager) ctx.getSystemService(Context.ALARM_SERVICE);
alarm.cancel(pending);
long interval = 60;
alarm.setRepeating(AlarmManager.ELAPSED_REALTIME, SystemClock.elapsedRealtime(),interval, pending);
appWidgetManger.updateAppWidget(appWidgetId, remoteViews);
super.onStart(intent, startId);
}
@Override
public IBinder onBind(Intent arg0) {
return null;
}
}
我遇到的问题是服务似乎永远不会被调用。我在服务的 onStart 方法中设置了断点,但我从来没有到达那里。有人可以帮忙吗?
如果您为我的程序建议不同的结构,也请告诉我。
编辑:我忘了添加清单代码。在应用程序标签之间,我在小部件的接收器对象后面有这段代码:
<service android:name=".UpdateWidgetService"></service>
这个对吗?
我真的希望有人能给我一个解决方案或提示。