How to call fragment method from main activity

Question

I have method in fragment class. I want to call that method from main activity but I don't want to use FragmentById (or) FragmentByTag.

My fragment method:

public void setItemFromDrawer(String sourceTag, String destTag) {
    //dosomething
}

How to call above method from main activity without using FragmentById (or) FragmentByTag?

when you load fragment using fragmentTransaction save fragment object and later on you can call any public method from that object — Khizar Hayat, Mar 02 '16 at 12:33
possible duplicate of http://stackoverflow.com/questions/10903077/calling-a-fragment-method-from-a-parent-activity?rq=1 — Jamil, Mar 02 '16 at 12:40

score 40 · Answer 1 · answered Mar 02 '16 at 13:01

40

First create an interface

public interface MyInterface
{
    void myAction() ;
}

Your fragment must implement this interface.

public MyFragment extends Fragment implements MyInterface

In your activity, define a field of type MyInterface :

  private MyInterface listener ;

  public void setListener(MyInterface listener)
  {
     this.listener = listener ;
  }

When creating your fragment and adding it :

setListener(myFragment);

Finally, when the condtion happens that you want to call the Fragment method, just call :

listener.myAction() ; // this will call the implementation in your MyFragment class.

answered Mar 02 '16 at 13:01

Farhad Faghihi

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I always find interfaces effective and the best option. This is the answer I'll recommend more. – Carlos Anyona Feb 01 '19 at 21:40
Simple and best answer! – Android learner Nov 27 '19 at 15:10
`setListener(myFragment);` - where do you set that??????? – ekashking Jan 29 '22 at 09:20
When creating your fragment and adding it! in your activity. @ekashking – Farhad Faghihi Jan 30 '22 at 21:49
What if I add it in ViewPager? – ekashking Feb 02 '22 at 05:37

score 9 · Answer 2 · edited Apr 06 '16 at 12:18

9

it means your calling a fragment method

((YourFragmentClass) fragment).Yourmethod();

edited Apr 06 '16 at 12:18

Prasad Khode

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answered Mar 03 '16 at 05:30

user5466222

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score 7 · Answer 3 · answered Apr 02 '18 at 09:08

7

To better explain the answer by user5466222 :

YourFragmentClass fragment = new YourFragmentClass();
((YourFragmentClass) fragment).yourmethod();

answered Apr 02 '18 at 09:08

Sif

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If it was just that easy .... but it's not. `Attempt to invoke virtual method 'java.lang.String android.content.Context.getPackageName()' on a null object reference` – ekashking Dec 15 '21 at 01:03

score 2 · Answer 4 · edited Mar 02 '16 at 12:56

2

In Activity use something like this where you load your fragment:

FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(container, fragment);

transaction.addToBackStack(null); // if you want to store transaction        
transaction.commit();
currentFragment = fragment; // currentFragment is global Fragment variable

Use following line where you want to call fragment's method

currentFragment.setItemFromDrawer("sourceTag","destTag");

edited Mar 02 '16 at 12:56

Rohit5k2

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answered Mar 02 '16 at 12:42

Khizar Hayat

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currentFragment = fragment; In this line fragment is what? – hikoo Mar 02 '16 at 13:08
the fragment you are loading. in which your function implemented – Khizar Hayat Mar 02 '16 at 13:24

score -2 · Answer 5 · answered Mar 02 '16 at 13:12

-2

((YourFragment Class) fragment).Your method();

its worked form me

answered Mar 02 '16 at 13:12

user5466222

161
1
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6

fragment meant what? – hikoo Mar 03 '16 at 04:48

How to call fragment method from main activity

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