Please read the documentation. As I said in my original post, this is for
when your activity gets killed while it is in the background. When you
press back, the default implementation is to finish() the activity so there
is no longer any instance data.
On Tue, Aug 25, 2009 at 6:57 AM, sdphil <phil.pellouch...@gmail.com> wrote:
>
> hm... okay, so I check for null in my onCreate() method.
>
> public void onCreate(Bundle savedInstanceData) {
> if (savedInstanceData == null) {
> // do everything I did before.
> // show splash screen
> super.onCreate(savedInstanceState);
> }
> }
>
> However, now if I'm in my app, I click on "home", and then click on
> the icon again, it behaves as expected, it simply brings the app back
> in the expected state. If I hit "back" and then click on the icon
> again, it behaves like I launched a brand new app - shows the splash
> screen, etc...
>
> On Aug 24, 11:24 pm, Dianne Hackborn <hack...@android.com> wrote:
> > The simple fact that it is non-null tells you. And you can have placed
> > anything else you want in there in onSaveInstanceState() for whatever
> other
> > data you want to retain. See here:
> >
> > http://developer.android.com/guide/topics/fundamentals.html#actlife
> >
> > and here:
> >
> > http://developer.android.com/reference/android/app/Activity.html
> >
> >
> >
> > On Mon, Aug 24, 2009 at 10:51 PM, sdphil <phil.pellouch...@gmail.com>
> wrote:
> >
> > > "You can use the state passed in to onCreate() to determine whether
> > > you are starting for the first time or not."
> >
> > > How do I do that?
> >
> > > I'm looking at onCreate --
> >
> > > public void onCreate(Bundle savedInstanceState) {
> >
> > > and I look at savedInstanceState, nothing jumps out at me...
> >
> > > On Aug 24, 10:39 pm, Dianne Hackborn <hack...@android.com> wrote:
> > > > If you just want pressing back to not close the activity, just catch
> the
> > > > BACK key and call Activity.moveTaskToBack() instead of letting it do
> the
> > > > default behavior (of calling finish()).
> >
> > > > There is no need to use launchMode nor alwaysRetainTaskState.
> >
> > > > However, you DO need to deal with the normal lifecycle behavior -- in
> > > > particular, when you are in the background, regardless of how this
> > > happened,
> > > > the system is free to kill your process, so when the user next
> returns to
> > > > your app a new instance of your activity will be created. You can
> use
> > > the
> > > > state passed in to onCreate() to determine whether you are starting
> for
> > > the
> > > > first time or not.
> >
> > > > Also, a "quit" menu on an android application is not normal,
> expected,
> > > nor
> > > > desired. Please don't do it; there is no need. I think you will
> have a
> > > > much better time if you try to design your app to follow the kind of
> flow
> > > > shown by the existing applications, rather than trying to make it
> work
> > > like
> > > > a desktop application.
> >
> > > > For example: you could save your current state to persistent storage
> when
> > > > the user leaves the app, and restore it when they return, so they
> know
> > > they
> > > > will always come back to the same thing. If it makes for them to
> > > actually
> > > > throw away that state, you could have an option for them to reset the
> app
> > > so
> > > > they can decide to do that at the time they want, rather than having
> to
> > > > decide earlier on to have this happen as a side-effect of some
> unusual
> > > > "quit" command.
> >
> > > > On Mon, Aug 24, 2009 at 10:16 PM, sdphil <phil.pellouch...@gmail.com
> >
> > > wrote:
> >
> > > > > I want my application to work like this:
> >
> > > > > 1. When the user launches the application, it starts up.
> > > > > 2. When the user hits back, or home, the application is still
> running
> > > > > (although not visible).
> > > > > 3. If the user hits "menu->quit" the application exits cleanly.
> > > > > 4. If the user starts the application, hits "home" and selects the
> > > > > application icon *again*, I want it to bring up the existing
> insance
> > > > > of the application with whatever activity state it had before it
> left.
> > > > > 5. I do not ever want more than one instance of my application to
> be
> > > > > running (i.e. singleton).
> > > > > 6. I always want to retain activity stack/state. when you come
> back
> > > > > into the application, it's like you never left.
> >
> > > > > <?xml version="1.0" encoding="utf-8"?>
> > > > > <manifest xmlns:android="
> http://schemas.android.com/apk/res/android";
> > > > > package="com.company.gui"
> > > > > android:versionCode="1"
> > > > > android:versionName="1.0">
> > > > > <application android:icon="@drawable/icon"
> > > > > android:label="@string/app_name"
> > > > > android:debuggable="true">
> > > > > <activity android:name=".Main"
> > > > > android:launchMode="singleTask"
> > > > > android:alwaysRetainTaskState="true"
> > > > > android:label="@string/app_name"
> > > > > android:screenOrientation="portrait"
> > > > > android:theme="@android:style/Theme.NoTitleBar">
> > > > > <intent-filter>
> > > > > <action android:name="android.intent.action.MAIN" />
> > > > > <category
> > > > > android:name="android.intent.category.LAUNCHER" />
> > > > > </intent-filter>
> > > > > </activity>
> >
> > > > > <activity android:name=".SplashScreen"
> > > > > android:label="@string/app_name">
> > > > > </activity>
> >
> > > > > </application>
> > > > > <uses-sdk android:minSdkVersion="3" />
> > > > > <uses-permission android:name="android.permission.INTERNET"></uses-
> > > > > permission>
> > > > > </manifest>
> >
> > > > > my main activity onCreate() looks like this:
> >
> > > > > startActivityForResult( new Intent(this,
> SplashScreen.class),
> > > > > SPLASH_REQUEST_ID );
> > > > > new Thread() {
> > > > > public void run() {
> > > > > try {
> > > > > Thread.sleep(4 * 1000);
> >
> > > > > // put initialization stuff
> > > here.
> >
> > > > > } catch (InterruptedException e) {
> > > > > e.printStackTrace();
> > > > > }
> > > > > finishActivity( SPLASH_REQUEST_ID );
> > > > > }
> > > > > }.start();
> >
> > > > > setContentView(R.layout.main);
> >
> > > > > If I leave the application by hitting home and then selecting the
> icon
> > > > > again, it starts with the splash screen again!
> >
> > > > > any ideas on how to best fix this?
> >
> > > > > tia.
> >
> > > > --
> > > > Dianne Hackborn
> > > > Android framework engineer
> > > > hack...@android.com
> >
> > > > Note: please don't send private questions to me, as I don't have time
> to
> > > > provide private support, and so won't reply to such e-mails. All
> such
> > > > questions should be posted on public forums, where I and others can
> see
> > > and
> > > > answer them.
> >
> > --
> > Dianne Hackborn
> > Android framework engineer
> > hack...@android.com
> >
> > Note: please don't send private questions to me, as I don't have time to
> > provide private support, and so won't reply to such e-mails. All such
> > questions should be posted on public forums, where I and others can see
> and
> > answer them.
> >
>
--
Dianne Hackborn
Android framework engineer
hack...@android.com
Note: please don't send private questions to me, as I don't have time to
provide private support, and so won't reply to such e-mails. All such
questions should be posted on public forums, where I and others can see and
answer them.
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