Resume activity from notification calling onCreate

Question

I am trying to resume my activity from a notification, but it is recreating the activity and not resuming.

As all posts regarding this issue, mention creating a PendingIntent and setting this with the appropriate flags (as shown in code below), and adding the singleTop|singleInstance to the AndroidManifest.

Notification Code:

NotificationManager mNotifyMan = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
        mNotifyMan.cancelAll();
        Notification.Builder mNB = new Notification.Builder(this);
        mNB.setOngoing(true);
        Intent intent = new Intent(parentContext, main.class);
        intent.setFlags(Intent.FLAG_ACTIVITY_BROUGHT_TO_FRONT);
        PendingIntent pendingIntent = PendingIntent.getActivity(parentContext, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);

        mNB.setContentIntent(pendingIntent);
        mNB.setSmallIcon(R.drawable.ic_notify_icon);
        mNB.setLargeIcon(BitmapFactory.decodeResource(getResources(), R.mipmap.ic_noti_large));
        mNB.setContentTitle(Title);
        mNB.setContentText(Message);
        mNB.setColor(0);
        mNotifyMan.notify(777, mNB.build());

I understand one must pass an intent with the current context.

When resuming an activity via the onPause() on onResume(), it resumes and restores the last activity state, i.e. a thread counter running has incremented values.

Problem:

When resuming from the notification (i.e. clicking on the notification), the activity is recreated. I have attempted to resolve this by

when onPause() is executed, sending the current activity state via base class to the notification, thus recreating the notification with the current state.

Here is my AndroidManifest:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.cynetstudios.wifimanager">

    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
    <uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
    <uses-feature android:name="android.hardware.wifi" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme"
        android:launchMode="singleInstance">

        <activity android:name="com.cynetstudios.frequencyselector.main" android:configChanges="orientation|screenSize|keyboardHidden">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <service android:name="com.cynetstudios.frequencyselector.serviceWifiFreqManager" android:exported="false"/>
    </application>

</manifest>

I might be missing something trivial, any advice?

Using `singleInstance` launch mode is not the correct way to deal with this. It will break your app big time if your app has more than 1 `Activity`. You should look at http://stackoverflow.com/questions/5502427/resume-application-and-stack-from-notification/5502950#5502950 — David Wasser, Jul 13 '16 at 12:47

score 4 · Accepted Answer · answered Jul 13 '16 at 11:23

You can set your Activity's launchMode SingleTask, SingleTop or SingleInstance depending on how you want your activity to act.

Later you can handle your activity's onNewIntent method if your activity is open when user clicks your active notification.

Also you need to define activity's launchMode in that atcitvity's part. I edited your xml.

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.cynetstudios.wifimanager">

    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
    <uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
    <uses-feature android:name="android.hardware.wifi" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">

        <activity android:name="com.cynetstudios.frequencyselector.main"
            android:configChanges="orientation|screenSize|keyboardHidden"
            android:launchMode="singleInstance">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <service android:name="com.cynetstudios.frequencyselector.serviceWifiFreqManager" android:exported="false"/>
    </application>

</manifest>

I hope this'll help you.

score 1 · Answer 2 · answered Jul 13 '16 at 10:59

1

launchMode should be used in Activity section (not application)

answered Jul 13 '16 at 10:59

Oleksandr

1,492
3
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13

thanks, the guide I followed showed the launchMode in the application tag, this works, thanks – CybeX Jul 14 '16 at 10:08

score 1 · Answer 3 · answered Jul 13 '16 at 11:32

1

Intent intent = new Intent(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_LAUNCHER);
intent.setClass(this, main.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);
startActivity(intent);

You can try this Intent. Such an intent is used by system app launcher, which will just show(no recreate) your activity if it is not killed.

answered Jul 13 '16 at 11:32

空気嫁

186
5

This works, but then it doesn't call `onNewIntent`, so I can't put extras into the Intent, that could be used... Any idea how to overcome this? – android developer Apr 08 '18 at 19:38
I use Rxbus to send extra data. The intent above seems cannot take extras when AMS dealing with ActivityRecord and task history – 空気嫁 Apr 13 '18 at 04:37

score 0 · Answer 4 · answered Jul 13 '16 at 11:01

0

Try

Intent.FLAG_ACTIVITY_CLEAR_TOP

with

Intent.FLAG_ACTIVITY_NEW_TASK

Set them as flags for the intent

answered Jul 13 '16 at 11:01

ammcom

992
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according to the docs, CLEAR_TOP clears all activities till where this one is, thus bringing it to the top – CybeX Jul 13 '16 at 11:05
That means it will not start a new instance of the activity – ammcom Jul 13 '16 at 11:08

score 0 · Answer 5 · edited Jul 13 '16 at 15:40

0

Try this it may help you:

intent.setFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);

and as @Alexander says put android:launchMode="singleTop" into activity tag

edited Jul 13 '16 at 15:40

MarkoHiel

15,481
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answered Jul 13 '16 at 11:10

Mehul

9
3

Resume activity from notification calling onCreate

5 Answers5