Navigate back to activity from fragment - android

I have class Demo and I am extends the demo by FragmentActivity class. Also I have another class Fragment1 extends Fragment. And the onclick of button i am navigate from activity Demo to the Fragment Fragment1. Now I want to come back on Demo from the Fragment1. So how can I back to Demo activity?
Thanks.

Your question is lacking a lot of detail, so I'm taking a stab in the dark here, but...
I presume in your onClick code, you use the Fragment Manager to create a new Fragment Transaction, then add the fragment to that transaction and commit it?
Your problem with the activity being closed when you hit the back button is likely because your fragment was not added to something called the "back stack". You can find to documentation here http://developer.android.com/reference/android/app/FragmentTransaction.html#addToBackStack%28java.lang.String%29, but crucially the main thing you need to do is modify your code to include the line below:
FragmentManager fragmentManager = getFragmentManager()
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.add(R.id.fragment_container, new Fragment1());
fragmentTransaction.addToBackStack("Transaction ID"); // <-- This is key!
fragmentTransaction.commit();
Once that's done, Android will remember the adding of the fragment as a navigation act, and should reverse the transaction when the back button is hit.
If this wasn't what you're looking for, or if it doesn't work, please provide some more detail and some code samples and I can take another look.

Try adding the fragment you want to go back to manually to the backstack.
FragmentTransaction transaction = getFragmentManager().beginTransaction();
YourFragmentName myFragment = new YourFragmentName();
transaction.replace(R.id.fragment_container, myFragment);
//if you with to add it to backStack, do this, otherwise skip the line below
transaction.addToBackStack(null);
transaction.commit();

Related

How do i get the onloaded fragment?

I wanted to know how I can get the Fragment which is onloaded on my Acticvity.
The background behind this is, that I want to change the onBackPressed method that it's switching to the right fragments. At the moment when I press "Back" the app closes, because I work alot with fragments.
Use addToBackStack on your fragment transaction. This way when you press the back key the transaction gets rolled back and thus your fragment disappears.
I got a solution for the problem:
Fragment fragment = new Fragment();
FragmentManager manager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = manager.beginTransaction();
fragmentTransaction.add(R.id.Layout,Fragment);
fragmentTransaction.addToBackStack("flow1");
fragmentTransaction.commit();

back stack and statically added fragment

I have a fragment added statically from XML I want to replace this fragment by another fragment, I did that by adding this code:
CFragment singleStationFragment = new CFragment();
android.support.v4.app.FragmentTransaction transaction = getChildFragmentManager().beginTransaction();
transaction.replace(R.id.layoutlist, singleStationFragment);
transaction.addToBackStack(null);
transaction.commit();
the problem is that when I press the back button the first fragment is not shown because it was not added through a transaction and the manager doesn't know about it, is there a way I could add the first fragment (ALREADY ADDED FROM XML), to my backstack or I could just show it when I click back instead of exiting the app ? Thanks !
As far as I'm aware you will have to add your first fragment to the activity in code rather than in the layout file. Do this with the add method of FragmentTransaction
transaction.add(R.id.FragmentContainer, fragment);

Android Fragments - How to implement Backstacking and Recalling previous fragment

I have android screen layout shown below
Apps screen divided into 3 fragments, Header, Footer and Content. Header and Footer fragments are fixed. Content fragment is changing according to content. I replaces fragment1-fragment3 according to need. Initially Fragment1 is shows in content area. When i press a next button fragment1 is replace by fragment2. This is the order. I have question, if i press another button previous, how can i return to previous fragment ( fragment2 -> fragment1). Is any built in mechanism available in fragment class.
Please guide me...
thanks in advance
try this code
FragmentTransaction tx = fragmentManager.beginTransation();
tx.replace( R.id.fragment, new MyFragment() ).addToBackStack( "tag" ).commit();
Whenever you try to call new fragment then add back stack for it through
ft.addToBackStack(null);
And now if you want to back from one fragment to another then, make one method..
public void DeleteCurrentFragment()
{
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
Fragment currentFrag = getSupportFragmentManager().findFragmentById(R.id.detailFragment);
String fragName = "NONE";
if (currentFrag!=null)
fragName = currentFrag.getClass().getSimpleName();
if (currentFrag != null)
transaction.remove(currentFrag);
transaction.commit();
}
And after that call this:
getSupportFragmentManager().popBackStack();
DeleteCurrentFragment();
you can try something like:
FragmentManager manager = getSupportFragmentManager();
FragmentTransaction ft = manager.beginTransaction();
ft.add(R.id.contentFragment, <your fragment>);
ft.addToBackStack(null);
ft.commit();
so suppose you're on fragment1 and after doing some stuff you want push fragment2 then on your contentFragment you can add or replace the fragment (fragment2 in this case) as per your requirement. Now when you call addToBackStack it means add this transaction to the back stack. So that the transaction will be remembered after it is committed, and will reverse its operation when later popped off the stack. Internally it maintains a stack so you don't want to do anything. At last when you press back button from fragment2 it checks whether the transaction having any fragment in its stack, if yes then it calls it. Its like top of stack. When you call addToBackStack in that stack fragment1 is added. So when you press back button stack's top is fragment1 so it calls it.
It happens when you press hardware back button. If you want to do this on any button, then on that button's click listener simply onBackPressed() method.

Android Fragment Unable to go back

I have an app that uses fragments with tabs/viewpager
[Tab 1][Tab 2][Tab 3]
Tab2 has a ListView and in the onClick method of the ListView I am showing a detail view with the following code
FragmentTransaction transaction = getChildFragmentManager().beginTransaction();
NextFragment nextFragment = new NextFragment();
transaction.replace(R.id.container, nextFragment);
transaction.addToBackStack(null);
transaction.commit();
The issue is that in the NextFragment when I use the hardware back button the whole app closes?
I'm not sure why it doesn't let you return when back is pressed, but what I've done in my application is the following:
I have overriden the onBackPressed action and created a check that once it is pressed and the user is in the fragment that he wants to return from, just create another fragment transaction to the previous fragment.
I have done so because I needed to update the previous fragment, but I'm sure there is a better way to solve your problem.

Weird android fragment issue using back stack

I have following issue with Android compatibility package fragments.
There is following hierarchy of fragments:
A(login) -> B(dashboard) -> C(details)
Login fragment is added with function:
private void addFragment(Fragment f) {
FragmentTransaction ft = mFragmentManager.beginTransaction();
ft.replace(R.id.main_content, f);
ft.commit();
}
After successfull login dashboard is added same way, without adding transaction to backstack. C fragment is added like:
FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.replace(R.id.main_content, f, id);
ft.addToBackStack(null);
ft.commit();
So basically on detail screen I have logout button, which should bring me to login A and remove all fragments from backstack. According to android developer docs:
Whereas, if you do call addToBackStack() when removing a fragment, then the fragment is stopped and will be resumed if the user navigates back.
But it is not the issue in my case. When logout is pressed in C fragment:
getFragmentManager.popBackStackImmediate();
FragmentTransaction ft = mFragmentManager.beginTransaction();
ft.replace(R.id.main_content, new LoginFragment());
ft.commit();
onActivityCreated(), onStart() of B fragment are also called (instead of onResume written in docs), making my code crash because in this fragment Im starting some thread operation, and after adding login fragment I got IllegalStateException that fragment B is not attached to an activity (when thread operation is over it updates fragment UI) Do anyone knows how replace really works and how overcome this problem?
I guess you should call
addToBackStack for each fragment you add giving a different name to them.
Reading your code seems to me you don't do it.

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