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Previous activity get destroyed on view-pager page change

My Previous Activity gets Destroyed on view-pager page changed(of running Activity). Thus onBackPressed() my App gets closed. I don't want to recall previous Activity explicitly.
Assume FirstActivity then open SecondActivity which has one viewpager . When we change page in view pager in Second Activity then FirstActivity (which is in Background) gets destroyed. so when we come back and back press on SecondActivity application closed

Check whether you have called finish(); after starting the ViewPager activity.
Intent intent = new Intent(getBaseContext(), SomeActivity.class);
startActivity(intent);
finish(); // This will destroy current activity.

You should not use finish() method for your activity while starting a new Activity explicitly. Instead, you should handle your activity every time in onBackPressed() method. if you manage your activities using lifecycle states i think you will not need for further explicit call to your activity.

How to navigate back to previous Activity?

What I am trying to do is, there is no chance the two activities are running at the same time. So I am using for this method in my adaptor class.
Intent intent = new Intent().setClass(v.getContext(), WinnerDetailActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);
v.getContext().startActivity(intent);
((Activity)context).finish();
But when I click the back button, it doesn't go to the back activity.
What am I doing wrong?

Basically you should remove finish() method from your code so that it will not destroy that activity and keep it in stack.
Once you call the finish() you can not go back to previous activity. This question explains in details, what happens when you call finish() method.

Remove ((Activity)context).finish(); in your code,
because
here you are finishing your activity which means when you press back you don't have any activity on your stack to go back to.
Finish() method will destroy the current activity. You can use this method in cases when you dont want this activity to load again and again when the user presses back button. Basically it clears the activity from the current stack.
So,no need to use finish() here

Just remove this line:
((Activity)context).finish();

Called the Finish method of activity at button click.
finish() just lets the system know that the programmer wants the current Activity to be finished.
((Activity)context).finish();

That is because you are finishing your activity which means when you press back you don't have any activity on your stack to go back to.
so just remove finish so that i will push WinnerDetailActivity on top of your current activity and on back of WinnerDetailActivity it will open your current activity.
Intent intent = new Intent().setClass(v.getContext(), WinnerDetailActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);
v.getContext().startActivity(intent);
And also read about FLAG_ACTIVITY_SINGLE_TOP
If set, the activity will not be launched if it is already running at
the top of the history stack.

//Here intent.setFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP); will alway remain in intent stack unless you finish it and once this activity is resume.. then it will act as the stack has only on Activity running...
//So just remove ((Activity)context).finish();
Intent intent = new Intent().setClass(v.getContext(), WinnerDetailActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);
v.getContext().startActivity(intent);
((Activity)context).finish();

There is two way to resolve this
1.Just remove ((Activity)context).finish(); because Finish() method will destroy the current activity.
2.Just Add below method in your class
public void onBackPressed() {
super.onBackPressed();
startActivity(new Intent(CurrentActivity.this,DestinationActivity.class));
}
DestinationActivity means Activity where you want to move.

OnBack Pressed Method is used to go back to previous activity,
super.onBackPressed() is used to navigate to previous activity without super.onBackpress it is not possible to traverse to previous activity.
#Override
public void onBackPressed()
{
super.onBackPressed();
}

This can be done in two ways:
Method 1:
Whenever you're stating a New Activity from an Activity, Make sure that you don't call finish(). Calling finish() will destroy the Previous Activity in the Stack.
Next Method is by Overriding onBackPressed(), by doing so you can navigate to the desired Activity.
#Override
public void onBackPressed() {
super.onBackPressed();
Intent intent = new Intent( thisActivity.this, yourFirstActivity.class);
startActivity(intent);
finish();
}

Check if a previous activity exists

I have an activity. After checking some stuff, I want to go back to previous activity if a previous exists, and if not I want to start a SpecificActivity. How do i do it?
Edited:
Seems like no one is understanding what I meant, so let me rephrase. Lets say I am in Activity A. I don't know if A is the only activity in the stack. If there are other activities, then I want to finish A and pop the activity right below A in the stack into the foreground. If A is the only activity in the stack, I want to start some activity Z. How do i do it?

You have to pass class name as intent extra from both Splash and DashboardActiviy.
In List Activity you have to get the class name using getIntent().
When the user click back button, you need to check the class name based on that you can take decision.
if(name.equalIgnorecase(DashboardActivit.class.getSimpleName()){
//Add your intent
}else{
//
}
This may give you definite solution to you.Give a try

you can simply override the onBackpress()
#Override
public void onBackPressed() {
super.onBackPressed();
startActivity(new Intent(this, Destination_Activity.class));
finish();
}

call the next activity like.
Intent intent = new Intent(this,Your_Next_Activity.class);
startActivity(intent);
then it will call your another activity and your current activity will be on background if you will use finish() after calling next activity it will finish your current activity so don't use finish() after calling your next activity in this scenario.
After that when you press back button it will automatically finish current activity.

back to first activity from each activity and recreate first activity

I have 3 activity, I want to return to the first activity and Refresh it after clicking on the button at second and Third activity, without using "new Intent(...)"!
I use this code:
ActivityFirst actFirst = (ActivityFirst) _context;
actFirst.recreate();
but it doesn't work! with Error : java.lang.ClassCastException
Is there any way to refresh first activity from second or third activity without use below code?
Intent intent = new Intent(this, ActivityFirst.class);
startActivity(intent);

You cannot refresh your first Activity because the thread is paused when the Activity is not in the foreground. Also the reason you are getting a ClassCastException I'm assuming is because your trying to cast your second or third Activity into the first Activity by passing your current Context.
You should just refresh your first Activity inside onResume like so:
#Override
protected void onResume() {
super.onResume();
recreate();
}
To start your first Activity again you could call this.
Intent intent = new Intent(this, FirstActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intent);

If you want to finish second or third activity when you click on button on these activity then just use onActivityResult in First Activity and refresh you first activity.
If you only want to refresh without finish second ot third activity then send broadcast message to first activity.
Let me know this is useful for you?

Go through Activity Life Cycle, When you have opened the 2nd activity the first activity will be in pause state.so while resuming the activity you can refresh the activity.Try these method to implement it : onResume()onPause()

startActivity(new Intent(B.this,A.class));
finish();
If you pass Intent from second activity(B.this) to first activity(A.class) ; it will be recreate that first activity. When you press back than not second activity open because of finish();.

How to go back to an already launched activity in android

I want to go back to an already launched activity without recreating again.
#Override
public void onBackPressed() {
Intent i = new Intent(SecondActivity.this, FirstActivity.class);
this.startActivity(i);
}
Instead of doing is there any other way to go back to another activity which is already created, which I get back with " Back button "

Add android:launchMode="singleTop" in the FirstActivity declaration in your AndroidManifest.xml like so
<activity
android:name=".FirstActivity"
android:launchMode="singleTop"/>
You could also try the following if SecondActivity was started from FirstActivity
#Override
public void onBackPressed() {
this.finish();
}

Whenever you start a new activity with an intent you can specify an intent flag like this:
// this flag will cause the launched activity to be brought to the front
// of its task's history stack if it is already running.
intent.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
or
// If set and this intent is being used to launch a new activity from an
// existing one, the current activity will not be counted as the top activity
// for deciding whether the new intent should be delivered to the top instead
// of starting a new one.
intent.addFlags(Intent.FLAG_ACTIVITY_PREVIOUS_IS_TOP);

When starting SecondActivity do not finish the first activity so when you go back , you will be taken to the first activity.
Intent i = new Intent(FirstActivity.this,SecondActivity.class);
startActivity(i);

On your second Activity, close the Activity calling finish() instead of creating a Intent for the other screen.
By calling finish() the Application will go back in the Activity stack and show the previous Activity (if its not finished()).

Don't call finish() on 1st Activity, when you start 2nd Activity. When back is pressed on 2nd Activity, it finishes itself and goes back to 1st Activity by default. onCreate() is not called for 1st Activity in this case. No need to override onBackPressed() in 2nd Activity.
However, Android can destroy 1st Activity when you are using 2nd Activity, to reclaim resources, or, if you have checked Don't keep activities in Developer options. In such case you can use onSaveInstanceState() to save data and onRestoreInstanceState() to use it again in 1st Activity. You can also get the saved data in onCreate(). Here is how it works. Also, onSaveInstanceState() is called only if android decides to kill the Activity and not when user kills the Activity(e.g. using back button).