How to call method defined in Fragment from MainActivity

Question

I am trying to call a method defined in a Fragment. e.g. I have the below method in a fragment

public void testMethod(){
        Toast.makeText(getActivity(),"Hi",Toast.LENGTH_SHORT).show();
    }

I want to call this method from MainActivity. I defined it as below.

private void callMethodFromFragment() {
        TestFragment testFragment = new TestFragment();
        testFragment.testMethod();
    }

I get the following error

java.lang.IllegalStateException: Could not execute method of the activity
            at android.view.View$1.onClick(View.java:4000)
            at android.view.View.performClick(View.java:4754)

Here is my activity_main.xml layout

<android.support.v4.widget.DrawerLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent">


    <FrameLayout
        android:id="@+id/content_frame"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />


    <ListView
        android:id="@+id/left_drawer"
        android:layout_width="240dp"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        android:choiceMode="singleChoice"
        android:divider="@android:color/transparent"
        android:dividerHeight="0dp"
        android:background="#fff"/>
</android.support.v4.widget.DrawerLayout>

[This](http://stackoverflow.com/questions/10903077/calling-a-fragment-method-from-a-parent-activity) might be helpful — Prudhvi, Apr 20 '15 at 18:48
I see you can access it from id or tag. But I don't have fragment defined in layout . I only have FrameLayout and ListView — user2661518, Apr 20 '15 at 19:02
Could you please show more code and what layout files you have? — Prudhvi, Apr 20 '15 at 19:09

Dimitar Darazhanski · Accepted Answer · 2015-04-20T19:24:15.230

3

Give your fragment a tag when adding it to the activity like so:

getFragmentManager().beginTransaction().add(R.id.content_frame, testFragment, "myTag").commit();

Then you can get the fragment by tag:

TestFragment fragment = (TestFragment) getFragmentManager().findFragmentByTag("myTag");
if (fragment) {
fragment.testMethod();
}

edited Apr 20 '15 at 19:24

answered Apr 20 '15 at 19:14

Dimitar Darazhanski

2,188
20
22

what should be R.id.fragment_container according to my layout file? Should be content_frame or left_drawer? – user2661518 Apr 20 '15 at 19:25

How to call method defined in Fragment from MainActivity

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