How to prevent to create every time Instance of Store activity?
When I call startActivity(new Intent(this,StoreActivity.class)), it will create new instance and call OnCreate Method in StoreActivity. I want to call one time Oncreate.
Is this Possible ?
Do this
startActivity(new Intent(
this,StoreActivity.class).setFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP));
From Android Documentation
public static final int FLAG_ACTIVITY_SINGLE_TOP
If set, the activity will not be launched if it is already running at the top of the history stack.
Constant Value: 536870912 (0x20000000)
Start your activity like this:
Intent storeIntent = new Intent(this, StoreActivity.class);
storeIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_SINGLE_TOP | Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
startActivity(storeIntent);
It will call onCreate() only once on first launch of activity, if activity is already running it calls only onNewIntent() instead of create new instance of activity or calling onCreate.
This is not possible since each time you press back button, onBackPressed() method is called which actually destroys your StoreActivity.
If you want this method to not destroy your activity, just remove or comment out super.onBackPressed() line in this method.
In this case your activity will not be destroyed when back button is pressed, but then you will have to use any other logic to bring your MainActivity to top of the stack.
try to finish the first activity after starting the new one,
add this code after the Intent command.
finish();
like that:
startActivity(new Intent(this, newActivity.class));
finish();
check this link
Finish an activity from another activity
I have a view in my android app that needs to open another view
and also close\finish all the calling hierarchy that made it open.
How can i do this?
If i use this code, the finish() is never called no?
Intent intent = new Intent(A.this, B.class);
setResult(RESULT_OK);
startActivity(intent);
finish();
You can clear whole stack using:
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
this is a solution if you want to start new activity, and close all activities that were open before it.
Google has an informative article on the Android back stack here.
In your code the .finish() is called and your calling activity should finish, but only that Activity and not others in the back stack. You can maintain some control of your back stack via Intent flags that are explained in the article, i.e.FLAG_ACTIVITY_NEW_TASK, FLAG_ACTIVITY_CLEAR_TOP, FLAG_ACTIVITY_SINGLE_TOP.
Another method is to use startActivityForResult(...) and close unwanted Activities in the onActivityResult(..) method in your Activity when it returns to the foreground..
My code allows me to launch a new activity/class:
Intent intent = new Intent(activity1.this, activity2.class);
startActivity(intent);
finish();
What if i have an activity already open, and just want to go back to it instead of reopening a new one, thus having multiple open of same.. So i want to switch back to an already open activity/class ?
Intent intent = new Intent(activity1.this, activity2.class);
intent .setFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
startActivity(intent);
It's the same thing. Android OS doesn't create 2 different versions of your activity, it works with already created activities.
Really simple:
finish();
If you want to choose an already existing activity in the backstack and not simply the latest opened that will be more complex and I don't know if you can modify the normal application workflow
Add this
FLAG_ACTIVITY_REORDER_TO_FRONT to your Intent you use with startActivity() .
Also remove finish()
If I'm getting you right, you need to use Intent.FLAG_ACTIVITY_REORDER_TO_FRONT flag. In this case your activity, if it was created before, will be brought to the front. As documentation states,
If set in an Intent passed to Context.startActivity(),
this flag will cause the launched activity to be brought
to the front of its task's history stack if it is already running.
My application has the following flow screens :
Home->screen 1->screen 2->screen 3->screen 4->screen 5
Now I have a common log out button in each screens
(Home/ screen 1 / screen 2 /screen 3/ screen 4 / screen 5)
I want that when user clicks on the log out button(from any screen), all the screens will be finished and a new screen Log in will open .
I have tried nearly all FLAG_ACTIVITY to achieve this.
I also go through some answers in stackoverflow, but not being able to solve the problem.
My application is on Android 1.6 so not being able to use FLAG_ACTIVITY_CLEAR_TASK
Is there any way to solve the issue ?
Use:
Intent intent = new Intent(getApplicationContext(), Home.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);
This will clear all the activities on top of home.
Assuming you are finishing the login screen when the user logs in and home is created and afterward all the screens from 1 to 5 on top of that one. The code I posted will return you to home screen finishing all the other activities. You can add an extra in the intent and read that in the home screen activity and finish it also (maybe launch login screen again from there or something).
I am not sure but you can also try going to login with this flag. I don't know how the activities will be ordered in that case. So don't know if it will clear the ones below the screen you are on including the one you are currently on but it's definitely the way to go.
You may try Intent.FLAG_ACTIVITY_CLEAR_TASK|Intent.FLAG_ACTIVITY_NEW_TASK. It will totally clears all previous activity(s) and start new activity.
Before launching your new Activity, simply add the following code:
finishAffinity();
Or if you want it to work in previous versions of Android:
ActivityCompat.finishAffinity(this);
When the user wishes to exit all open activities, they should press a button which loads the first Activity that runs when your application starts, clear all the other activities, then have the last remaining activity finish. Have the following code run when the user presses the exit button. In my case, LoginActivity is the first activity in my program to run.
Intent intent = new Intent(getApplicationContext(), LoginActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
intent.putExtra("EXIT", true);
startActivity(intent);
The above code clears all the activities except for LoginActivity. Then put the following code inside the LoginActivity's onCreate(...), to listen for when LoginActivity is recreated and the 'EXIT' signal was passed:
if (getIntent().getBooleanExtra("EXIT", false)) {
finish();
}
Why is making an exit button in Android so hard?
Android tries hard to discourage you from having an "exit" button in your application, because they want the user to never care about whether or not the programs they use are running in the background or not.
The Android OS developers want your program to be able to survive an unexpected shutdown and power off of the phone, and when the user restarts the program, they pick up right where they left off. So the user can receive a phone call while they use your application, and open maps which requires your application to be freed for more resources.
When the user resumes your application, they pick up right where they left off with no interruption. This exit button is usurping power from the activity manager, potentially causing problems with the automatically managed android program life cycle.
I guess I am late but there is simple and short answer.
There is a finishAffinity() method in Activity that will finish the current activity and all parent activities, but it works only in Android 4.1 or higher.
For API 16+, use
finishAffinity();
For below 16, use
ActivityCompat.finishAffinity(YourActivity.this);
Hope it helps!
Intent intent = new Intent(this, classObject);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | IntentCompat.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intent);
This Will work for all Android versions. Where IntentCompat the class added in Android Support library.
Use the following for activity
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_NEW_TASK);
remove CLEAR_TASK flag for fragment use.
I hope this may use for some people.
On a side note, good to know
This answer works (https://stackoverflow.com/a/13468685/7034327)
Intent intent = new Intent(getApplicationContext(), LoginActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK|Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
this.finish();
whereas this doesn't work
Intent intent = new Intent(getApplicationContext(), LoginActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
.setFlags() replaces any previous flags and doesn't append any new flags while .addFlags() does.
So this will also work
Intent intent = new Intent(getApplicationContext(), LoginActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
From developer.android.com:
public void finishAffinity ()
Added in API level 16
Finish this activity as well as all activities immediately below it in the current task that have the same affinity. This is typically used when an application can be launched on to another task (such as from an ACTION_VIEW of a content type it understands) and the user has used the up navigation to switch out of the current task and in to its own task. In this case, if the user has navigated down into any other activities of the second application, all of those should be removed from the original task as part of the task switch.
Note that this finish does not allow you to deliver results to the previous activity, and an exception will be thrown if you are trying to do so.
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
In my case I use finishAffinity() function in last activity like:
finishAffinity()
startHomeActivity()
Hope it'll be useful.
A solution I implemented for this (I think I found it on Stack Overflow somewhere, but I don't remember, so thanks to whoever did that in the first place):
From any of your activities do this:
// Clear your session, remove preferences, etc.
Intent intent = new Intent(getBaseContext(), LoginActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);
Then in your LoginActivity, overwrite onKeyDown:
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
moveTaskToBack(true);
return true;
}
return super.onKeyDown(keyCode, event);
}
For logout button on last screen of app, use this code on logout button listener to finish all open previous activities, and your problem is solved.
{
Intent intent = new Intent(this, loginScreen.class);
ntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intent);
}
Intent i1=new Intent(getApplicationContext(),StartUp_Page.class);
i1.setAction(Intent.ACTION_MAIN);
i1.addCategory(Intent.CATEGORY_HOME);
i1.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
i1.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
i1.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(i1);
finish();
i have same problem
you can use IntentCompat , like this :
import android.support.v4.content.IntentCompat;
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK |IntentCompat.FLAG_ACTIVITY_CLEAR_TASK);
this code work for me .
Android api 17
instead of using finish() just use finishAffinity();
Log in->Home->screen 1->screen 2->screen 3->screen 4->screen 5
on screen 4 (or any other) -> StartActivity(Log in) with FLAG_ACTIVITY_CLEAR_TOP
for API >= 15 to API 23
simple solution.
Intent nextScreen = new Intent(currentActivity.this, MainActivity.class);
nextScreen.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | IntentCompat.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(nextScreen);
ActivityCompat.finishAffinity(currentActivity.this);
If you are using startActivityForResult() in your previous activities, just override OnActivityResult() and call the finish(); method inside it in all activities.. This will do the job...
When user click on the logout button then write the following code:
Intent intent = new Intent(this, LoginActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);
And also when after login if you call new activity do not use finish();
I guess I am late but there is simple and short answer. There is a finishAffinity() method in Activity that will finish the current activity and all parent activities, but it works only in Android 4.1 or higher.
For API 16+, use
finishAffinity();
For below 16, use
ActivityCompat.finishAffinity(YourActivity.this);
Hope it helps!
shareedit
answered May 27 '18 at 8:03
Akshay Taru
Simply, when you go from the login screen, not when finishing the login screen.
And then in all forward activities, use this for logout:
final Intent intent = new Intent(getBaseContext(), LoginScreen.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
context.startActivity(intent);
It works perfectly.
If you log in the user in screen 1 and from there you go to the other screens, use
Intent intent = new Intent(this, Screen1.class);
intent.addFlags(FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);
I found this way, it'll clear all history and exit
Intent startMain = new Intent(Intent.ACTION_MAIN);
startMain.addCategory(Intent.CATEGORY_HOME);
startMain.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(startMain);
Intent intent = new Intent(getApplicationContext(), SplashScreen.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);
finish();
System.exit(0);
I found this solution to work on every device despite API level (even for < 11)
Intent intent = new Intent(getApplicationContext(), LoginActivity.class);
ComponentName cn = intent.getComponent();
Intent mainIntent = IntentCompat.makeRestartActivityTask(cn);
startActivity(mainIntent);
Best way to close all the previous activities and clear the memory
finishAffinity()
System.exit(0);
I have tried the flags on my end and still haven't worked. I have an application with a very similar design and I have a possible solution in terms of logic. I have built my Login and Logout using shared preferences.
If I logout, data in my shared preferences is destroyed/deleted.
From any of my activities such as Home.java I check whether shared preferences has data and in this case it won't because I destroyed it when I logged out from one of the screens. Therefore logic destroys/finishes that activity and takes me back to the Login activity. You can replicate this logic in all your other activities.
However remember to perform this check inside onPostResume() because this is what is called when you go back to Home.java
Code Sample Below:
#Override
protected void onPostResume() {
SharedPreferences pref = this.getSharedPreferences("user_details", Context.MODE_PRIVATE);
if (pref.getAll().isEmpty()){
//Shared Preferences has no data.
//The data has been deleted
Intent intent = new Intent(getApplicationContext(), Login.class);
startActivity(intent);
finish();
//Finish destroys that activity which in our case is the Home.java
}
super.onPostResume();
}
In Kotlin this way:
in Another Activity (with some classes), under Imports
var activity:Activity?=null
get() = field
set(value) {
field = value
}
Then, under onCreate
activity=this
in MainActivity now:
activity?.finish()
I want to invoke one application from another application.
My Java file code:
Intent intent = new Intent(Intent.ACTION_RUN);
intent.setComponent(new ComponentName("Package name", "class name"));
startActivity(intent);
But I'm getting problem in specifying exact package path and I don't know permission for that code in Manifest. Please, help me on this.
I am going to assume that you really mean that you want to launch another app, not another Activity in your app.
Then there are two ways to do this. You can try using an implicit intent which according to the docs, an (Implicit) intent is "an abstract description of an operation to be performed" that "provides for performing late runtime binding between code in different applications." Sort of like trying to launch a method over the wire using an interface. You cannot be sure exactly what the class of the object that is launched only that it can handle the action and categories that you declare.
The second approach is an explicit intent, which is more like making a concrete call over the wire. If you know the package and class name this should work.
Intent intent = new Intent(Intent.ACTION_MAIN);
//intent.putExtra("plain_text", "Testing");
intent.setClassName("packagename", "packagename.ClassName"); // Explicit Intent
try {
startActivity(intent);
}
catch (Exception e)
{
Log.d(TAG","onCreate",e);
}
}
You can add extra info using flags depending on your needs and where your are trying to launch from.
JAL
Starting an external activity from your app is done using a slightly different method to that which you are using. You need to create an intent with a given action. For example, launching an intent to fetch an image from the gallery would look like this:
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("image/*");
startActivityForResult(intent, IMAGE_PICK);
Note that you don't explicitly define the activity to be loaded, rather the kind of action you want to perform. Android will then pick (or have the user pick) an activity that has registered to handle this kind of intent to be run.
You might need to be a little more specific about what you're doing. If all you want to do is, say, launch another Activity from your main Activity, something like this would work:
Intent intent = new Intent(this, OtherActivity.class);
intent.putExtra("key", "data"); //put any data you want to pass into the new activity
startActivity(intent);
Then just make sure you put the new activity in your manifest like this:
<activity android:name=".OtherActivity"
android:label="#string/other"/>
If your goal is something else then you should be ore specific with what you want to do.