Question

Very strange thing here.

I initially had an activity that was the start up activity (Activity A). It had the tag android:launchMode="singleTask" associated with it. No problems. My requirements changed and now i’m making Activity B the startup activity. I copied the intent filter over, I changed the name to “.ActivityB” and I moved the launch mode tag over as well.

It seems to work okay; when I start the app I go to Activity B. However when I go from Activity B to Activity A and then click the back button the app exits and won’t reopen (it will reopen if I don’t have the launch mode tag.)

Another example. If I go from Activity A to Activity B to Activity A to Activity B everything is fine. When I click back i go to Activity A (as expected) however when I click back again I go to a previous instance of Activity A (uh oh) then I click back again and exit the app. Both times skipping Activity B.

I’m clearly overlooking something but I can’t figure out what. I’m not overriding any back button functionality and everything worked perfectly before I switched the start up activity.

Edit
The following is an excerpt from my manifest before any change

<activity android:name=".ActivityA" android:windowSoftInputMode="stateHidden" android:label="@string/app_name" android:launchMode="singleTask">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity android:name="ActivityB"></activity>

Here is an excerpt after the change

<activity android:name=".ActivityB" android:windowSoftInputMode="stateHidden" android:label="@string/app_name" android:launchMode="singleTask">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity android:name="ActivityA"></activity>

Answer 1

Sounds like Activity B is getting finish() called or something. I suggest putting in some log statements in OnCreate, OnPause, OnResume, and OnDestroy so you can monitor the life of Activity B. Its a highlander activity (there can only be 1) so you don’t have to worry about multiple instances being created. Also you might look into / override onNewIntent and placing some logging calls there.

Not really an answer, but dollars to donuts you or someone put a finish() call after starting Activity A, or when Activity B goes in the background and you’ve forgotten about it.

If that’s not the case I’d be interested in how/when Activity B dies. Usually if it stops because of some error upon returning to it, Android will bark at you but since you didn’t mention that I’d guess it isn’t.