Develop Reference

How to Control Android back stack

Lets say I have
A->B->C->D->E
In android back stack. I want to be able to get back to one of the following:
A->B->C
A->B
A
How can I achieve this? Hopefully without forcing back button clicks.

Using the image and information from the official developers page on Android tasks and back stack you can see that of all other ways to launch an Activity you can ensure such behavior only using the FLAG_ACTIVITY_CLEAR_TOP in your Intent flags.
Your regular back button proceeds as:
But when you specify this flag, you get a behavior like you need, as given by an example at this source:
consider a task consisting of the activities: A, B, C, D. If D calls
startActivity() with an Intent that resolves to the component of
activity B, then C and D will be finished and B receive the given
Intent, resulting in the stack now being: A, B.

Use FLAG_ACTIVITY_CLEAR_TOP flag.
Intent a = new Intent(this, A.class);
a.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(a);

Actually , to go "up" to the activity of your choice, you should use the "up" navigation as used on the action bar:
/** used to handle the "up" button on the action bar, to go to the defined top activity as written on the manifest */
public static void goUpToTopActivity(final Activity currentActivity) {
final Intent intent = NavUtils.getParentActivityIntent(currentActivity);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
NavUtils.navigateUpTo(currentActivity, intent);
}
in order to use it, you must set on the manifest to which activity this function should use (or you could of course set it yourself by changing the code) :
if you use actionBarSherlock, for each activity that you wish to let to go up, use:
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.your_app.activities.MainActivity" />
if you use the android framework (if your minSdk version is API 16 and above), use the "parentActivityName" attribute.

Suppose you are using Intent to move to another activity
Intent i = new Intent(A.this,B.class);
startActivity(i);
this code will take you to the 'B' Activity and when you press Back button it will again take you to the 'A' Activity . If you dont want to go back to activity 'A' you can use....
Intent i = new Intent(A.this,B.class);
i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(i);
For more information about Back Stack in Android Follow this link :
http://developer.android.com/guide/components/tasks-and-back-stack.html

Android:Delete a activity in backstack

I have got 4 activity let it be A->B->C->D.In every A,B,C activity user need to enter data all data will sent to server in C activity if the user data is correct he will move on to D activity and all the activity A,B,C removed from stack.If the data is in correct i need give the user to reenter data i.e is on back press it has to move C->B->A.My question is How to remove A,B,C activity when user enter D activity.

Use FLAG_ACTIVITY_CLEAR_TOP this shall solve your problem
From the Android documentation:
If set, and the activity being launched is already running in the
current task, then instead of launching a new instance of that
activity, all of the other activities on top of it will be closed and
this Intent will be delivered to the (now on top) old activity as a
new Intent.
For example, consider a task consisting of the activities: A, B, C, D.
If D calls startActivity() with an Intent that resolves to the
component of activity B, then C and D will be finished and B receive
the given Intent, resulting in the stack now being: A, B.
Use it like
Intent intent = new Intent(getApplicationContext(),
yourActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);
and also, take a look at this question:
Activity with Flag FLAG_ACTIVITY_CLEAR_TOP (android)
Edit : I thought you want to move to your home activity from D and want to remove all activities from stack
Your stack would be like homeactivity , A , B , C , D
so i gave you this solution as this shall remove all activities in stack on top of your home activity.
If you want to clear the the stack while going to D, for that you can use FLAG_ACTIVITY_TASK_ON_HOME or FLAG_ACTIVITY_CLEAR_TASK
But both of these for api level 11.

The correct answer interesting for me also, but I can offer a solution:
For example you start activity A from O: O->A->B->C->D.
On activity O you can put in android manifest android:launchMode="singleTop"
Then, when data are ok, you can start activity O with flag "FLAG_ACTIVITY_CLEAR_TOP" - it remove from stack A,B,C and will be called method onNewIntent (Intent intent) http://developer.android.com/reference/android/app/Activity.html#onNewIntent(android.content.Intent) in O, where you can start activity D.

You can start activities with startActivityForResult, and call setResult from for example activity D, in C activity you can listen activity result, and related of this result finish activity or not, or call setResalt from C activity ...

When you want to move D activity there you need to check your
conditions and if your condition is satisfied then you need to enter
into your Next activity(i.e., D) .In that case you need to use the
following code..
Intent intent = new Intent(this,D.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intent);
Suppose In on backpress you need to use finish(). to move back i.e., C
-> B -> A.

Try this piece of code with some modifications:
Intent intent = new Intent(this, D.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP); // To clean up all activities
startActivity(intent);

Try looking for Activity's public method startActivity(Intent i) and finish() here
In usage wise, it should look like this.
Intent i = new Intent(MainActivity.this, MainActivity.class);
startActivity(i);
finish();
Hope this helps :D

FLAG_ACTIVITY_CLEAR_TOP calls onCreate() instead of onResume()

So I have an abstract class extended through the entire app that overrides the back key to reorder Activity A to the front (With the flag).
So, it would be:
A > B > anywhere, and the back key should bring me back to A
I'm using the FLAG_ACTIVITY_CLEAR_TOP, but it is entirely refreshing A for some reason and I don't want that.
So: Flag_activity_clear_top is reloading the onCreate() rather than onResume(). What gives?

If you want the activity to just be brought to the top without restarting it set the launchMode of the activity to singleTop in the manifest. You will receive a call to onNewIntent when the activity is being brought to the top. onNewIntent is called before onResume. If you only want this behavior for the specific intent you can add the FLAG_ACTIVITY_SINGLE_TOP(in addition to FLAG_ACTIVITY_CLEAR_TOP) to the intent with the addFlags call instead of the manifest.

Intent intent = new Intent(CurrentActivity.this, ActivityNeedOnTop.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
startActivity(intent);
CurrentActivity.this.finish();

From the API docs for FLAG_ACTIVITY_CLEAR_TOP
For example, consider a task consisting of the activities:
A, B, C, D. If D calls startActivity() with an Intent that
resolves to the component of activity B, then C and D
will be finished and B receive the given Intent,
resulting in the stack now being: A, B.
**The currently running instance of activity B in the above example
will either receive the new intent you are starting here in its
onNewIntent() method, or be itself finished and restarted with the new intent.**
So I think your activity is itself finished and restarted.

How to switch activities in Android?

Now I have 3 activities, activity1, activity2 and activity3. I open the activities in order and never close any of them. So now I am in activity3, but I want to go back to activity1 and it must be the one which I opened. Is there any way to do that?

start activity 1 from 3 with FLAG_ACTIVITY_CLEAR_TOP flag:
Intent intent = new Intent ( this, Activity1.class );
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);

according to developer doc, you should use FLAG_ACTIVITY_CLEAR_TOP into the intent you want to start.
FLAG_ACTIVITY_CLEAR_TOP :
If set, and the activity being launched is already running in the
current task, then instead of launching a new instance of that
activity, all of the other activities on top of it will be closed and
this Intent will be delivered to the (now on top) old activity as a
new Intent.
use addFlags before start back activity1.

finish() activity twice in android?

Okay say your using a app, and you opened a new activity and then opened another, you can end the activity your on by using finish(); and your back one activity, but how can you go back two activities, all the way back to the first one? I know you could use:
Intent savedGameIntent = new Intent(v.getContext(), firstclass.class);
v.getContext().startActivity(savedGameIntent);
But is that the best way to do it?

Use the flag Intent.FLAG_ACTIVITY_CLEAR_TOP.
Intent intent = new Intent(this,A.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);
From the documentation:
If set, and the activity being launched is already running in the current task, then instead of launching a new instance of that activity, all of the other activities on top of it will be closed and this Intent will be delivered to the (now on top) old activity as a new Intent.
So effectively, if you have A -> B -> C, and you intent to A with that flag set, B and C will close.

I believe that will start a new activity, not back up to the original one. It sounds like you want to finish the last and middle activities. If you start the last activity with startActivityForResult, you can then override onActivityResult in the middle activity, and call finish() from there.