There are six activities A,B,C,D,E and F. Each of them have been opened in the following order: A,B,C,D,E,F. When I now go from activity F to activity B, I would like to have a subsequent press on the back button open activity A. How can this outcome be achieved?
You can achieve this with Intent flags.
When you start Activity B from Activity F you use a flag in your intent.
Intent i = new Intent(context, B.class);
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
Intent.FLAG_ACTIVITY_CLEAR_TOP will cause all of the intermediate activities to be finished (C, D and F), and Intent.FLAG_ACTIVITY_SINGLE_TOP will make sure that you return to the same instance of Activity B.
If you want for activity B to be finished and a new instance to be created, remove Intent.FLAG_ACTIVITY_SINGLE_TOP
Also you can change activity B launchMode instead of using Intent.FLAG_ACTIVITY_SINGLE_TOP
Here are some more info on the matter
I am trying to start an activity B from activity A with intent set to Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK now i want to get back some data from Activity B to Activity A, and for that i am using startactivityforresult now the problem happening is that, when i am calling setresult from Activity B then my activity A's onactivityresult is not getting called.
Can anyone please tell me why is this happening, and if it is not possible to use startactivityforresult with (NEW_TASK and CLEAR_TASK) then what can i try instead of this.
Also I am trying to use above two intents because i want to clear my back stack when i want to open activity B.
In Activity A
Intent intent = new Intent(A.this, B.class);
Bundle args = new Bundle();
args.putString("from", "A");
intent.putExtras(args);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivityForResult(intent, 111);
On Activity B
Intent resultIntent = new Intent();
resultIntent.putExtras(data.getExtras());
setResult(Activity.RESULT_OK, resultIntent);
finish();
The answer to your question is simple :
the flag Intent.FLAG_ACTIVITY_NEW_TASK , is Incompatible with startActivityForResult().
So it wont work , any activity that is started by an Intent to which the flag "FLAG_ACTIVITY_NEW_TASK" was added can not return a result.
Here is the part of Android documentation that specify this.
It says :
This flag can not be used when the caller is requesting a result from
the activity being launched.
I don't want user to be able to go somewhere back from my LoginActivity.
This works nice from MainActivity (from Navigation Drawer):
Intent intent = new Intent(this, LoginActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
finish();
Result - back stack is cleared.
But when I'm trying to call this from my custom Dialog:
private Context mContext;
Intent intent = new Intent(mContext, LoginActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK);
dismiss();
mContext.startActivity(intent);
((Activity)mContext).finish();
back stack isn't clear, I can go back from my LoginActivity to previous window.
Tried to search the reason, but no result till now.
Try clearing your activity stack:
Set android:noHistory= "true" in your AndroidManifest.xml file in the <activity tag for the login activity.
http://developer.android.com/reference/android/R.styleable.html#AndroidManifestActivity_noHistory
I had a similar problem and adding android:launchMode="singleTop" to my activity in AndroidManifest.xml did the work.
I took the idea from this question
As the title says, Why intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP) or intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP) won't work?
I have 3 Activities let us say A, B and C.
When I am trying to launch Activity A from C with code:
Intent i = new Intent(this, A.class);
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(i);
It simply starts Activity A but doesn't clear the top.! -_-
I have also tried using setFlags().
I read different questions on SO about this problem, but I couldn't find the right answer. >_<
Somebody please help!
Edit
Code for onBackPressed() in activity 'A' as requested by #codeMagic.
#Override
public void onBackPressed(){
if(wvLogin.canGoBack())
wvLogin.goBack();
else
super.onBackPressed();
}
From the documentation for 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.
As you added in your comment, the activity A has been finished before calling B, so this situation doesn't apply. A new instance of activity A will be launched instead.
As I see it, you have two options here:
1) Use the Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK flags. This will start activity A as the root of the stack. It works, but any other activities in the stack will be lost. Assuming A was the first activity (or at least, that you are not interested in any previous activities in the task stack) then it doesn't matter. Note: CLEAR_TASK requires API Level 11.
2) Another possible solution (in case the previous assumption is not true) would be to not use intent flags at all:
B starts C with startActivityForResult().
Instead of calling A, C finishes, having set a result for B indicating that A must be launched.
In B.afterActivityResult(), finish B and launch A.
You are missing the Intent.FLAG_ACTIVITY_SINGLE_TOP flag
Try this:
Intent i = new Intent(this, A.class);
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
startActivity(i);
You used a diferrent intent: use the one you initialized:
Intent i = new Intent(this, A.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP); \\WRONG;;
startActivity(i);
solution:
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP); \\RIGHT;;
You could either put a noHistory true to the Activity A in the manifest
android:noHistory=true
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?
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.
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intent);
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.
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);
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
Add android:launchMode="singleTop" to the activity element in your manifest for Activity A
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).
Try using
intent.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);
and not
intent.setFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);
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
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>
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();
Use finishAffinity(); in task C when starting task A to clear backstack activities.
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.
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);
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.
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)
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.
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.
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
}
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();
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.
Kotlin example:
val intent = Intent(this#LoginActivity, MainActivity::class.java)
intent.flags = Intent.FLAG_ACTIVITY_CLEAR_TOP or Intent.FLAG_ACTIVITY_NEW_TASK
startActivity(intent)
finish()
logout.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
logout.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_CLEAR_TOP);
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();
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);
you wont get any activity pressing back button after that :
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_CLEAR_TASK |
Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
finishAffinity();
finish();
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);
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
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
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();