问题
I have a flashlight app with a widget. The widget is used to turn the flashlight on and off and does not display main activity or anything. After a few hours, however, the widget does nothing. I mean if you click it, nothing happens.
I have two classes to accomplish this a Provider
and a Receiver
.
Provider:
public class WidgetProvider extends AppWidgetProvider {
@
Override
public void onUpdate(Context context, AppWidgetManager appWidgetManager,
int[] appWidgetIds) {
Intent receiver = new Intent(context, FlashlightWidgetReceiver.class);
receiver.setAction("COM_FLASHLIGHT");
receiver.putExtra(AppWidgetManager.EXTRA_APPWIDGET_IDS, appWidgetIds);
PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, receiver, 0);
RemoteViews views = new RemoteViews(context.getPackageName(),
R.layout.appwidget_layout);
views.setOnClickPendingIntent(R.id.imageButton, pendingIntent);
appWidgetManager.updateAppWidget(appWidgetIds, views);
}
}
Receiver:
public class FlashlightWidgetReceiver extends BroadcastReceiver {
private static boolean isLightOn = false;
private static Camera camera;
MediaPlayer mp;@
Override
public void onReceive(Context context, Intent intent) {
RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.appwidget_layout);
if (isLightOn) {
views.setImageViewResource(R.id.imageButton, R.drawable.btn_switch_off);
mp = MediaPlayer.create(context, R.raw.light_switch_off);
} else {
views.setImageViewResource(R.id.imageButton, R.drawable.btn_switch_on);
mp = MediaPlayer.create(context, R.raw.light_switch_on);
}
mp.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
@
Override
public void onCompletion(MediaPlayer mp) {
// TODO Auto-generated method stub
mp.release();
}
});
mp.start();
AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(context);
appWidgetManager.updateAppWidget(new ComponentName(context, WidgetProvider.class),
views);
if (isLightOn) {
if (camera != null) {
camera.stopPreview();
camera.release();
camera = null;
isLightOn = false;
}
} else {
camera = Camera.open();
if (camera == null) {
Toast.makeText(context, "No Camera!", Toast.LENGTH_SHORT).show();
} else {
Camera.Parameters param = camera.getParameters();
param.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);
try {
camera.setParameters(param);
camera.startPreview();
isLightOn = true;
} catch (Exception e) {
Toast.makeText(context, "No Flash!", Toast.LENGTH_SHORT).show();
}
}
}
}
}
Setup:
<appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android"
android:minWidth="40dp"
android:minHeight="40dp"
android:maxWidth="40dp"
android:maxHeight="40dp"
android:updatePeriodMillis="86400000"
android:initialLayout="@layout/appwidget_layout"
android:resizeMode="horizontal|vertical">
</appwidget-provider>
Update: Reducing the update interval makes the widget refresh more often so if it's stuck it works again after 30 min and then it might freeze again sometime.
Update 2: Changing the date instantly freezes the widget until it's refreshed.
Update 3: Changing the date somehow restarts the launcher and whenever the launcher is restarted the widget freezes for 30 mins.
回答1:
Look for this post, I think this problem is explained here the dark side of app widgets
回答2:
Alright guys, I finally got time to fix this problem once and for all :)
I created more methods for the provider instead of doing everything in onUpdate, one important method needed:
public static PendingIntent buildButtonPendingIntent(Context context) {
Intent intent = new Intent();
intent.setAction("COM_FLASHLIGHT");
return PendingIntent.getBroadcast(context, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
}
And this method is called through the receiver when the widget is clicked using the code below:
private void turnFlash(Context context) {
RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.appwidget_layout);
views.setOnClickPendingIntent(R.id.imageButton, WidgetProvider.buildButtonPendingIntent(context));
}
That is all, no more hiccups!
来源:https://stackoverflow.com/questions/30180032/android-widget-stops-working-after-a-while