How can I return to a parent activity correctly?

Question

I have 2 activities (A and B) in my android application and I use an intent to get from activity A to activity B. The use of parent_activity is enabled:

 <activity
        android:name=".B"
        android:label="B" >
        <meta-data
            android:name="android.support.PARENT_ACTIVITY"
            android:value="com.example.app_name.A" />
  </activity>

I also use a theme which provides an UP-button.

So after I called activity B I can use the UP-button to get back to the activity A. The problem is that the application seems to call the onCreate()-function of activity A again and this is not the behaviour I need. I need activity A to look the same way like it looked before I called activity B.

Is there a way to achieve this?

EDIT

I didn't write any code to start activity B from activity A. I think it is auto-generated by Eclipse.

Class B looks like:

    @Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_b);
    getActionBar().setDisplayHomeAsUpEnabled(true);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.activity_b, menu);
    return true;
}


@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case android.R.id.home:
            NavUtils.navigateUpFromSameTask(this);
            return true;
    }
    return super.onOptionsItemSelected(item);
}

Crave

Post you code, for starting Activity A from B.. – Aryan

If I understand you right, you can use startActivityForResult() and return a resultCode or something. – Piccalilli

Please update your tagged correct answer! The CORRECT answer is coming from LorenzCK - not from user......! Tagging this as correct is misleading and makes even more programmers misunderstand up navigation as opposed to back navigation! – Bastardy

Gee, so many wrong answers here, could you please help in cleaning this up...? – Bastardy

@Crave - Correct answer as per your code design is updated. – Aryan

Note that NavUtils.navigateUpFromSameTask(this); will work correctly only for API level 15 and lower. For higher API levels, it recreates the Parent Activity. This is explained beautifully here, https://mcmap.net/q/136986/-up-navigation-broken-on-jellybean – Prisage

Try this solution in the child activity: https://mcmap.net/q/136987/-android-refresh-parent-activity-when-child-activity-finishes – Storytelling

Answer 1

You declared activity A with the standard launchMode in the Android manifest. According to the documentation, that means the following:

The system always creates a new instance of the activity in the target task and routes the intent to it.

Therefore, the system is forced to recreate activity A (i.e. calling onCreate) even if the task stack is handled correctly.

To fix this problem you need to change the manifest, adding the following attribute to the A activity declaration:

android:launchMode="singleTop"

Note: calling finish() (as suggested as solution before) works only when you are completely sure that the activity B instance you are terminating lives on top of an instance of activity A. In more complex workflows (for instance, launching activity B from a notification) this might not be the case and you have to correctly launch activity A from B.

Cerell

Here is the explanation from Android docs, The "standard" and "singleTop" modes differ from each other in just one respect: Every time there's a new intent for a "standard" activity, a new instance of the class is created to respond to that intent. Each instance handles a single intent. Similarly, a new instance of a "singleTop" activity may also be created to handle a new intent. However, if the target task already has an existing instance of the activity at the top of its stack, that instance will receive the new intent (in an onNewIntent() call); a new instance is not created. – Prisage

Note that according to the documentation navigateUpFromSameTask(...) should be adding FLAG_ACTIVITY_CLEAR_TOP to upIntent (via navigateUpTo(...) which should result in same behavior (according to this guide), but the flag is never set - and therefore this answer makes sense – Percussion

Answer 2

Updated Answer: Up Navigation Design

You have to declare which activity is the appropriate parent for each activity. Doing so allows the system to facilitate navigation patterns such as Up because the system can determine the logical parent activity from the manifest file.

So for that you have to declare your parent Activity in tag Activity with attribute

android:parentActivityName

Like,

<!-- The main/home activity (it has no parent activity) -->
    <activity
        android:name="com.example.app_name.A" ...>
        ...
    </activity>
    <!-- A child of the main activity -->
    <activity
        android:name=".B"
        android:label="B"
        android:parentActivityName="com.example.app_name.A" >
        <!-- Parent activity meta-data to support 4.0 and lower -->
        <meta-data
            android:name="android.support.PARENT_ACTIVITY"
            android:value="com.example.app_name.A" />
    </activity>

With the parent activity declared this way, you can navigate Up to the appropriate parent like below,

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
    // Respond to the action bar's Up/Home button
    case android.R.id.home:
        NavUtils.navigateUpFromSameTask(this);
        return true;
    }
    return super.onOptionsItemSelected(item);
}

So When you call NavUtils.navigateUpFromSameTask(this); this method, it finishes the current activity and starts (or resumes) the appropriate parent activity. If the target parent activity is in the task's back stack, it is brought forward as defined by FLAG_ACTIVITY_CLEAR_TOP.

And to display Up button you have to declare setDisplayHomeAsUpEnabled():

@Override
public void onCreate(Bundle savedInstanceState) {
    ...
    getActionBar().setDisplayHomeAsUpEnabled(true);
}

Old Answer: (Without Up Navigation, default Back Navigation)

It happen only if you are starting Activity A again from Activity B.

Using startActivity().

Instead of this from Activity A start Activity B using startActivityForResult() and override onActivtyResult() in Activity A.

Now in Activity B just call finish() on button Up. So now you directed to Activity A's onActivityResult() without creating of Activity A again..

Aryan

I don' know where startActivity() in activity B is called. I've posted the source code of activity B... – Crave

Instead of code line NavUtils.navigateUpFromSameTask(this); write finish() . – Aryan

It begs the question, how come Google doesn't mention anything about finish() or startActivityForResult() in their documentation on Navigation (developer.android.com/design/patterns/navigation.html) ? – Aleph

this sounds like a laborious workaround. @Cerell answer seems to be much better. – Ivanovo

Thanks a lot for using NavUtils.navigateUpFromSameTask(this). Big plus! I have been looking for a method like this to replace finish() which does not return to the parent activity under some circumstances. finish() is essentially going back to the previous activity that is not necessarily the parent activity. – Reclusion

Note that the AppCompatActivity class now has a onSupportNavigateUp method which handles everything. It should be better to use that instead of the NavUtils methods. – Bullnecked

Answer 3

I had pretty much the same setup leading to the same unwanted behaviour. For me this worked: adding the following attribute to an activity A in the Manifest.xml of my app:

android:launchMode="singleTask"

See this article for more explanation.

Shanel

From my point of view the correct solution to the problem. This will behave just like if you called finish() if the Activity exists in the task stack. If that is not the case it will be created and started. – Jessikajessup

This is not the correct way as it will create a new task unnecessarily every time, you should instead use the launchMode="singleTop". – Prisage

Answer 4

Although an old question, here is another (imho the cleanest and best) solution as all the previous answeres didn't work for me since I deeplinked Activity B from a Widget.

public void navigateUp() {
final Intent upIntent = NavUtils.getParentActivityIntent(this);
if (NavUtils.shouldUpRecreateTask(this, upIntent) || isTaskRoot()) {
    Log.v(logTag, "Recreate back stack");
        TaskStackBuilder.create(this).addNextIntentWithParentStack(upIntent).startActivities();
  } else {
    NavUtils.navigateUpTo(this, upIntent);
  }
}

[https://mcmap.net/q/136988/-navutils-navigateupto-does-not-start-any-activity ]

But also see: https://speakerdeck.com/jgilfelt/this-way-up-implementing-effective-navigation-on-android

Bouillon

Answer 5

A better way to achieve this is by using two things: call:

NavUtils.navigateUpFromSameTask(this);

Now, in order for this to work, you need to have your manifest file state that activity A has a parent activity B. The parent activity doesn't need anything. In version 4 and above you will get a nice back arrow with no additional effort (this can be done on lower versions as well with a little code, I'll put it below) You can set this data in the manifest->application tab in the GUI (scroll down to the parent activity name, and put it by hand)

Support node:

if you wish to support version below version 4, you need to include metadata as well. right click on the activity, add->meta data, name =android.support.PARENT_ACTIVITY and value = your.full.activity.name

to get the nice arrow in lower versions as well:

getSupportActionBar().setDisplayHomeAsUpEnabled(true);

please note you will need support library version 7 to get this all working, but it is well worth it!

Orchidaceous

Answer 6

What worked for me was adding:

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {

        switch (item.getItemId()) {
            case android.R.id.home:
                onBackPressed();
                return true;
            default:
                return super.onOptionsItemSelected(item);
        }
    }

    @Override
    public void onBackPressed() {
        finish();
    }

to TheRelevantActivity.java and now it is working as expected

and yeah don't forget to add:

getSupportActionbar.setDisplayHomeAsUpEnabled(true); in onCreate() method

Arabia

Answer 7

Adding to @LorenCK's answer, change

NavUtils.navigateUpFromSameTask(this);

to the code below if your activity can be initiated from another activity and this can become part of task started by some other app

Intent upIntent = NavUtils.getParentActivityIntent(this);
if (NavUtils.shouldUpRecreateTask(this, upIntent)) {
    TaskStackBuilder.create(this)
            .addNextIntentWithParentStack(upIntent)
            .startActivities();
} else {
    NavUtils.navigateUpTo(this, upIntent);
}

This will start a new task and start your Activity's parent Activity which you can define in Manifest like below of Min SDK version <= 15

<meta-data
        android:name="android.support.PARENT_ACTIVITY"
        android:value="com.example.app_name.A" />

Or using parentActivityName if its > 15

Benyamin

Note: Do declare parentActivityName for SDK >15 or else it'll give you some random crashes – Benyamin

Answer 8

I tried android:launchMode="singleTask", but it didn't help. Worked for me using android:launchMode="singleInstance"

Bunion

Adding android:launchMode="singleInstance" to parent activity solved problem for me – Acheron

Answer 9

I had a similar problem using android 5.0 with a bad parent activity name

<activity
        android:name=".DisplayMessageActivity"
        android:label="@string/title_activity_display_message"
        android:parentActivityName=".MainActivity" >
        <meta-data
            android:name="android.support.PARENT_ACTIVITY"
            android:value="com.example.myfirstapp.MainActivity" />
    </activity>

I removed the com.example.myfirstapp from the parent activity name and it worked properly

Frater

Answer 10

In Java class :-

    toolbar = (Toolbar) findViewById(R.id.apptool_bar);
    setSupportActionBar(toolbar);

    getSupportActionBar().setTitle("Snapdeal");

    getSupportActionBar().setHomeButtonEnabled(true);
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);

In Manifest :-

<activity
            android:name=".SubActivity"
            android:label="@string/title_activity_sub"
            android:theme="@style/AppTheme" >
            <meta-data android:name="android.support.PARENT_ACTIVITY" android:value=".MainActivity"></meta-data>
    </activity>

It will help you

Bani

Answer 11

Add to your activity manifest information with attribute

android:launchMode="singleTask"

is working well for me

Frances

Comlete flow is like that @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case android.R.id.home: NavUtils.navigateUpFromSameTask(this); return true; } return super.onOptionsItemSelected(item); } – Frances

Add to your manifest <activity android:name=".MainActivity" android:label="@string/title_activity_main" > </activity> <activity android:name=".CreateEventActivity" android:label="@string/title_activity_create_event" android:launchMode="singleTask" android:parentActivityName=".MainActivity" > <meta-data android:name="android.support.PARENT_ACTIVITY" android:value=".MainActivity" /> </activity> – Frances

Answer 12

try this:

Intent intent;
@Override
public void onCreate(Bundle savedInstanceState) {
    intent = getIntent();   
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_b);
    getActionBar().setDisplayHomeAsUpEnabled(true);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.activity_b, menu);
    return true;
}  

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case android.R.id.home:
            NavUtils.navigateUpTo(this,intent);
            return true;
    }
    return super.onOptionsItemSelected(item);
}

Brendon

Answer 13

    @Override
public boolean onOptionsItemSelected(MenuItem item) {
   switch (item.getItemId()) {
// Respond to the action bar's Up/Home button
    case android.R.id.home:
        finish();
        return true;
}
return super.onOptionsItemSelected(item);

like a Back press

Emmenagogue

Answer 14

Going into my manifest and adding android:launchMode="singleTop" to the activity did the trick for me.

This specifically solved my issue because I didn't want Android to create a new instance of the previous activity after hitting the Up button in the toolbar - I instead wanted to use the existing instance of the prior activity when I went up the navigation hierarchy.

Reference: android:launchMode

Mortification

Answer 15

Try this solution use NavUtils.navigateUpFromSameTask(this); in the child activity: https://mcmap.net/q/136987/-android-refresh-parent-activity-when-child-activity-finishes

Storytelling

Answer 16

In any context, If you want's to open parent activity on onBackPressed

protected fun navigateToParent() {
        NavUtils.getParentActivityIntent(this)?.let { upIntent ->
            if (NavUtils.shouldUpRecreateTask(this, upIntent) || isTaskRoot) {
                Timber.d("navigateToParent: sourceActivity should recreate")
                startActivity(upIntent)
            } else {
                Timber.d("navigateToParent: sourceActivity in stack, just finish")
            }
        }
        super.onBackPressed()
    }

Set android:parentActivityName in manifest

 <activity
            android:name=".feature.signup.SignUpActivity"
            android:parentActivityName=".feature.welcome.WelcomeActivity"
            android:windowSoftInputMode="adjustResize" />

Faline