Develop Reference

Clear Android activity stack and start activity

I know this question has been answered in another posts also. But it doesn't solve my issue.
I have 3 screens: A,B and Home. App starts with A, then goes to B and then to Home page. But I want to delete activities A and B when it reaches Home activity, so that when back is pressed app exits.
I tried:
Intent.FLAG_ACTIVITY_CLEAR_TOP. It works fine when back is pressed. App quits. But if I again open the app from background, it starts with screen B.
Intent.FLAG_ACTIVITY_NEW_TASK. This works exactly as I want. But when Home activity starts, there is a sudden glitch in the screen and it is not smooth.

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.

Try the following code:
Intent i = new Intent(YourActivity.this, HomeActivity.class);
i2.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
finish();
startActivity(i);

You can do this way also, for your splashScreen(A) you can set nohistory=true in AndroidMenifest.xml, and goto Activity(B), and when you are going on Activity Home from Activity(B) finish activity(B) than goto Home activity.
so both of your previous activities will not store in stack.
And on Activity B override onBackPresh() method but remove super.backpresh() in side it. and start your activity A with finish this current activity, it will work.

Previous activity stays on activity stack

I'm using this library which is a Wizard.
When user is done with the Wizard and clicks Done button he moves to another Activity.
I have added to Manifest file android:noHistory="true" for the WizardActivity and also when I start the next activity im doing it like this :
Intent intent = new Intent(this, ProjectsActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
Nevertheless when user click backs he still goes to the WizardActivity. I'd like the user either to exit or go the activity that started the WizardActivity.
Thank you

finish() the activity after launching the other Activity. i.e after startActivity(intent) add finish()

reopen app from background

When user press "Home Button" my app go to Background, but is still running. I need bring my app to front again. For example i've this code:
Context ctx=getApplicationContext();
Intent i =ctx.getPackageManager().getLaunchIntentForPackage("com.example.test");
ctx.startActivity(i);
but this code is to open app in different activity, there are a method or something to do this "correctly"?

You can simulate the "launching" of the app the same way that Android launches the app when the user selects it from the list of available apps. If the user starts an application that is already running, Android just brings the existing task to the foreground (which is what you want). Do it like this:
Intent intent = new Intent(context, SplashScreen.class);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK); // You need this if starting
// the activity from a service
intent.setAction(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_LAUNCHER);
startActivity(intent);
(Source: https://stackoverflow.com/a/12075313/3529926)

You can set this flag to your intent
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
and set the launch mode of your activity to single task in manifest (add this is your activity tags):
android:launchMode="singleTask"

Need code for exit from app in android

Hello i am new to android.I am implementing some application and it have some activities.
Suppose if i launch the app for first time,it's entering in to A then going to B after that C,D,E..... (Here A,B,C,D,E are activities).If i press back button at E then it is going D--> C--> B--> A like this.
Now i want to implement code to exit/quit from the app when i am at D.
I wrote following code but this code is working for closing current activity and going to prev activity.means going C.
finish();
Then i tried with following code and it is working fine and closing current application successfully and going to device home screen.But if i want open the application again then it is starting form D instead of A.
intent = new Intent(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_HOME);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
copied from here
Please help me to solve my problem.

Use these flags to lunch the activity and clear the activity stack
Intent intent = new Intent(this, YourActivityD.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
Be aware that FLAG_ACTIVITY_CLEAR_TASK is only available from API 11
See: http://developer.android.com/guide/components/tasks-and-back-stack.html

Try this:
finish();
System.exit(0);

Start fresh application every time

Right now, what is happening is when I press home-key, last active activity is displayed. But what I want is to start the application as new every time the user presses home key and start the app from launcher. Please help

I think you can override onPause() event when you pressing home button and in there you can implement finishing your activity.
with setting intent flag as FLAG_ACTIVITY_CLEAR_TOP on starting your Activity your back stack would be clear so with finishing the last activity there is no activity on the task and stack

While creating intent you can set the flag. for example
Intent intent = new Intent();
intent.setFlags(Intent.FLAG_ACTIVITY_NO_HISTORY | Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS);