Back button in an Activity without recreate previo

Question

I have a master activity that is a menu (A). The activity A have 6 fragments. One of them is a gallery of pictures (Figure 1). When you touch a picture you go to the picture details activity (B) (Figure 2). I add the tag "parentName" to the activity B in the AndroidManifest.xml. So the parent of the activity B is the activity A. The problem is: when you are in activity B and you press the Up Button (Figure 2) the activity A is recreated and it shows the first fragment of the activity A (not the gallery fragment). I want the same behavior of the Instragram app when you back to a previous activity. It seems like the Instagram app don't recreate the previous activity. The expected behavior is also similar to the behavior of the back button (Figure 3). How can I achieve this behavior? Thanks

Figure 1. Picture details Activity

Figure 2. Picture details Activity

Figure 3. Back button

Answer 1

May be programatically you are using this :

getFragmentManager().beginTransaction().replace(R.id.content_frame, new FragmentB(),null).addToBackStack(null).commit();

Replace it with this line :

getFragmentManager().beginTransaction().add(R.id.content_frame, fragment,null).addToBackStack(null).commit();

Answer 2

I've solved my problem easily. I just had to add the tag android:launchMode="singleTop" to the activity A. I also add the next code in the activity A but probably isn't necessary. I hope you find it useful.

@Override
protected void onSaveInstanceState(Bundle outState)
{
    super.onSaveInstanceState(outState);
}

@Override
protected void onRestoreInstanceState(Bundle savedInstanceState)
{
    super.onRestoreInstanceState(savedInstanceState);
}