How to clear the Android Stack of activities?

Question

I have an application with several Activities in Android and I want the user to be able to log-out by pressing a menu button. The problem I have is that

A) Android doesn't let you terminate the application and
B) even when I send the user to the LoginActivity again they can always press back and get right back to the previous activity they were in.

I already tried to launch the Activity with the two following flags:

Intent intent  = new Intent(this, LoginActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);        
startActivity(intent);

I also tried with each one of them by themselves.

I also tried calling finish() after startActivity(intent) as I read in another StackOverflow question.

Solution 1

In your login activity, override the back button, so it hides your app instead of finishing the activity:

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    if (keyCode == KeyEvent.KEYCODE_BACK) {
        moveTaskToBack(true);
        return true;
    }
    return super.onKeyDown(keyCode, event);
}

Also be sure to set android:alwaysRetainTaskState="true" on the root activity, so Android doesn't clear your stack (including the login activity) after 30min of inactivity from user.

Then just call finish() when there is a successful login.

Solution 2

This should be bitwise OR'd or you end up overwriting the earlier flag.

intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);

Like so:

intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TOP);

Solution 3

As per Wakka in Removing an activity from the history stack...

---

Add android:noHistory="true" attribute to your <activity> in the AndroidManifest.xml like this:

<activity android:name=".MyActivity"
    android:noHistory="true">
</activity>

Solution 4

If you are using Android API 11 or above, you can use the following code to clear the stack.

intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);

Solution 5

This wont clear your activity back stack.

Even after following all the above answer, when I pressed the back button It showed the last activity for a second before closing the app.

This is what I did:

@Override
public void onBackPressed() { 
    Intent startMain = new Intent(Intent.ACTION_MAIN);
    startMain.addCategory(Intent.CATEGORY_HOME);
    startMain.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    startActivity(startMain);
}

Now my app exits on back press :) without any hassle.

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Comments

[Totic]

Thanks, your code got me in the right path, but this will do the same: @Override public void onBackPressed(){ moveTaskToBack(true); }

[amity]

i have try it many time but not get required result. please help me

[mxcl]

The only way this works is if the activity you are trying to start is already in the activity stack. Android Y U SO WEIRD?

[Brandon]

Please keep in mind that much has changed between SDK versions of Froyo and Cupcake when comparing answers. In other words, something which worked a certain way in 2010 might work differently now.

[amalBit]

Yes, you are right. I will kepp that in mind. Thanks.

[Luca Fagioli]

This won't work with API level < 11. Check my answer for a solution compliant with API level >= 1.

[Nagaraj Alagusundaram]

Perfect! this is simple

[Ruchir Baronia]

Okay, so I have a user constantly switching between activities, meaning they may have switched 15 activities in 20 seconds. Could that be a cause of an out of memory error? What should I do to fix it? Thanks!

[Ruchir Baronia]

Okay, so I have a user constantly switching between activities, meaning they may have switched 15 activities in 20 seconds. Could that be a cause of an out of memory error? What should I do to fix it? Thanks!

[Ruchir Baronia]

Okay, so I have a user constantly switching between activities, meaning they may have switched 15 activities in 20 seconds. Could that be a cause of an out of memory error? What should I do to fix it? Thanks!

[Ruchir Baronia]

Okay, so I have a user constantly switching between activities, meaning they may have switched 15 activities in 20 seconds. Could that be a cause of an out of memory error? What should I do to fix it? Thanks!

[Ruchir Baronia]

Okay, so I have a user constantly switching between activities, meaning they may have switched 15 activities in 20 seconds. Could that be a cause of an out of memory error? What should I do to fix it? Thanks!'

[Gelldur]

@RuchirBaronia it shouldn't cause out of memory. Probably something is keeping you activities in memory :) Check: blogs.innovationm.com/…