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?

Lipread

when you load fragment using fragmentTransaction save fragment object and later on you can call any public method from that object – Seleta

I didn't understand.. Can you give any example code – Lipread

possible duplicate of #10903577 – Causeway

try this https://mcmap.net/q/88078/-calling-a-fragment-method-from-a-parent-activity – Centerpiece

Answer 1

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.

Scurrilous

I always find interfaces effective and the best option. This is the answer I'll recommend more. – Trinitrophenol

Simple and best answer! – Toughminded

setListener(myFragment); - where do you set that??????? – Rog

When creating your fragment and adding it! in your activity. @Rog – Scurrilous

What if I add it in ViewPager? – Rog

Answer 2

it means your calling a fragment method

((YourFragmentClass) fragment).Yourmethod();

Omeara

Answer 3

To better explain the answer by user5466222 :

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

Rosiorosita

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 – Rog

Answer 4

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");

Seleta

currentFragment = fragment; In this line fragment is what? – Lipread

the fragment you are loading. in which your function implemented – Seleta

Answer 5

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

its worked form me

Omeara

fragment meant what? – Lipread