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Android: Clear the back stack

Posted by: admin March 10, 2020 Leave a comment

Questions:

In Android I have some activities, let’s say A, B, C.

In A, I use this code to open B:

Intent intent = new Intent(this, B.class);
startActivity(intent);

In B, I use this code to open C:

Intent intent = new Intent(this, C.class);
startActivity(intent);

When the user taps a button in C, I want to go back to A and clear the back stack (close both B and C). So when the user use the back button B and C will not show up, I’ve been trying the following:

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

But B and C are still showing up if I use the back button when I’m back in activity A. How can I avoid this?

How to&Answers:

Try adding FLAG_ACTIVITY_NEW_TASK as described in the docs for FLAG_ACTIVITY_CLEAR_TOP:

This launch mode can also be used to
good effect in conjunction with
FLAG_ACTIVITY_NEW_TASK: if used to
start the root activity of a task, it
will bring any currently running
instance of that task to the
foreground, and then clear it to its
root state. This is especially useful,
for example, when launching an
activity from the notification
manager.

So your code to launch A would be:

Intent intent = new Intent(this, A.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK); 
startActivity(intent);
CurrentActivity.this.finish(); // if the activity running has it's own context


// view.getContext().finish() for fragments etc.

Answer:

intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intent);

Answer:

What about adding in manifests file for related activity :

android:noHistory="true"

to the activity definition of B and C ? They will not be added to the backstack. Not sure if that is what you want.

Answer:

This bothers me for a long time .Finally I worked it out by doing this:

In fragment,use:

Intent intent = new Intent(view.getContext(), A.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK); 
startActivity(intent);

In Activity,use(add one more intent flag Intent.FLAG_ACTIVITY_CLEAR_TASK compared to fragment):

Intent intent = new Intent(this, MainActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);

Answer:

  1. Add android:launchMode="singleTop" to the activity element in your manifest for Activity A
  2. Then use intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP) and
    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK) when starting Activity A

This means that when Activity A is launched, all tasks on top of it are cleared so that A is top. A new back stack is created with A at the root, and using singleTop ensures you only ever launch A once (since A is now on top due to ..._CLEAR_TOP).

Answer:

Starting in API 16 (Jelly Bean), you can just call finishAffinity().

Now you can also call ActivityCompat.finishAffinity(Activity activity) with the compatibility library.

Be sure to set taskAffinity in the manifest to a package name unique to that group of activities.

See for more info:
http://developer.android.com/reference/android/support/v4/app/ActivityCompat.html#finishAffinity%28android.app.Activity%29

Answer:

Try using

intent.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);

and not

intent.setFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);

Answer:

If your application has minimum sdk version 16 then you can use
finishAffinity()

Finish this activity as well as all activities immediately below it in the current task that have the same affinity.

This is work for me
In Top Payment screen remove all back-stack activits,

 @Override
public void onBackPressed() {
         finishAffinity();
        startActivity(new Intent(PaymentDoneActivity.this,Home.class));
    } 

http://developer.android.com/reference/android/app/Activity.html#finishAffinity%28%29

Answer:

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>

Answer:

For future research, try this code.

Intent intent = new Intent(context, LoginActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
finish();

Answer:

Use finishAffinity(); in task C when starting task A to clear backstack activities.

Answer:

Use this code for starting a new Activity and close or destroy all other activity stack or back stack.

Intent intent = new Intent(this, MainActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intent);

Answer:

Use finishAffinity() to clear all backstack with existing one.

Suppose, Activities A, B and C are in stack, and finishAffinity(); is called in Activity C, 

    - Activity B will be finished / removing from stack.
    - Activity A will be finished / removing from stack.
    - Activity C will finished / removing from stack.

Answer:

I found an interesting solution which might help. I did this in my onBackPressed() method.

finishAffinity();
finish();

FinishAffinity removes the connection of the existing activity to its stack. And then finish helps you exit that activity. Which will eventually exit the application.

Answer:

I found the answers here a little misleading because the code in the original question seems to work fine for me?

With A being the root activity, starting it from B or C only with FLAG_ACTIVITY_CLEAR_TOP does remove B and C from the back stack.

Answer:

In kotlin it is almost same like java. Only | symbol is replaced by or text.
So, it is written like-

intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK or Intent.FLAG_ACTIVITY_NEW_TASK)

Answer:

I tried all solutions and none worked individually for me.
My Solution is :

Declare Activity A as SingleTop by using [android:launchMode="singleTop"] in Android manifest.

Now add the following flags while launching A from anywhere. It will clear the stack.

Intent in = new Intent(mContext, A.class);
in.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK );
startActivity(in);
finish();

Answer:

Intent.FLAG_ACTIVITY_CLEAR_TOP will not work in this case. Please use (Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK)

For more detail please check out this documentation.

Answer:

It sounds to me like you need to start Activity C from Activity B by using startActivityForResult(). When you click a button in Activity C, call setResult(RESULT_OK) and finish() so Activity C is ended. In Activity B, you could have the onActivityResult() respond by also calling finish() on itself, and you’d then be taken back to Activity A.

Answer:

logout.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
logout.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

Answer:

You can use this example to call your Activity A from Activity C

Intent loout = new Intent(context, LoginActivity.class);
loout.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
context.startActivity(loout);

Answer:

for me adding Intent.FLAG_ACTIVITY_CLEAR_TASK solved the problem

Intent i = new Intent(SettingsActivity.this, StartPage.class);
                i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP  | Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_NEW_TASK);
                startActivity(i);
finish();

Answer:

Advanced, Reuseable Kotlin:

You can set the flag directly using setter method. In Kotlin or is the replacement for the Java bitwise or |.

intent.flags = FLAG_ACTIVITY_NEW_TASK or FLAG_ACTIVITY_CLEAR_TASK

If use this more than once, create an Intent extension function

fun Intent.clearStack() {
    flags = Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TASK
}

You can then directly call this function before starting the intent

intent.clearStack()

If you need the option to add additional flags in other situations, add an optional param to the extension function.

fun Intent.clearStack(additionalFlags: Int = 0) {
    flags = additionalFlags or Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TASK
}

Answer:

In addition to FLAG_ACTIVITY_CLEAR_TOP, you may try adding Intent.FLAG_ACTIVITY_SINGLE_TOP as well:

intent.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);

Answer:

The given code works correctly. I have tried in the Application Life Cycle sample.

I haven’t got B and C in the back stack after starting activity A with flag, FLAG_ACTIVITY_CLEAR_TOP

Answer:

i called activity_name.this.finish() after starting new intent and it worked for me.

I tried "FLAG_ACTIVITY_CLEAR_TOP" and "FLAG_ACTIVITY_NEW_TASK"

But it won’t work for me… I am not suggesting this solution for use but if setting flag won’t work for you than you can try this..But still i recommend don’t use it

Answer:

Add NO History Flag in the intent.

In activity B, start the activity C as below >>>>>>

Intent intent = new Intent(this, C.class);
intent.setFlags(intent.getFlags() | Intent.FLAG_ACTIVITY_NO_HISTORY); 
startActivity(intent);
finish();

Answer:

In manifest

android:launchMode="singleTask"

and

intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);

Answer:

Either add this to your Activity B and Activity C

android:noHistory="true"

or Override onBackPressed function to avoid back pressing with a return.

@Override
public void onBackPressed() {
   return;
}

Answer:

Use setFlags() method for clear back side opened all activity close and start yourActvity

Intent intent = new Intent(getApplicationContext(), yourActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intent);