How to add an onClickListener on a View in custom fragment?

Question

I am creating a Login and signup form. I have created two custom fragments, one for login and one for signup. Both have some clickable textViews, and I want to add onClickListener to these textViews, however I am getting Null Pointer Exception when I am trying to access these views from my fragment class.

My custom login fragment class:

package com.example.contactsaver


import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.fragment.app.Fragment
import kotlinx.android.synthetic.main.fragment_login.*


class LoginFragment: Fragment(){

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {

        val view = inflater.inflate(R.layout.fragment_login,null)
        return view
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        tvNewAccount.setOnClickListener {
             //todo
        }
    }
}

Main Activity:

package com.example.contactsaver

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import androidx.fragment.app.Fragment


class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        val loginFragment = LoginFragment()
        setFragment(loginFragment)
    }



    private fun setFragment(fragment: Fragment){
        supportFragmentManager.beginTransaction().apply {
            replace(R.id.flFragments,fragment)
            commit()
        }
    }


}

This is the error:

java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
        at com.example.contactsaver.LoginFragment.onCreate(LoginFragment.kt:26)

Does this answer your question? [What is a NullPointerException, and how do I fix it?](https://stackoverflow.com/questions/218384/what-is-a-nullpointerexception-and-how-do-i-fix-it) — Zain, Jun 10 '21 at 22:40

score 0 · Accepted Answer · answered Jun 10 '21 at 23:06

You're setting your click listener inside onCreate which is getting called before the view is instantiated (it's called before onCreateView) so that reference you're getting from Kotlin synthetics is null. Move your click listener to onViewCreated like this

class LoginFragment: Fragment(){

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {

        val view = inflater.inflate(R.layout.fragment_login,null)
        return view
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)


        tvNewAccount.setOnClickListener {
             //todo
        }
    }
}

Thank you ! @Amin. It solves the problem. – Sreshtha Mehrotra Jun 10 '21 at 23:45 — Sreshtha Mehrotra, Jun 10 '21 at 23:45

How to add an onClickListener on a View in custom fragment?

1 Answers1