free geoip
36

Fix Kotlin Fragments Not Displaying Issue

If you’re building an Android app using Kotlin and encounter the issue of fragments not displaying properly, you’re not alone.…

If you’re building an Android app using Kotlin and encounter the issue of fragments not displaying properly, you’re not alone. This is a common hurdle faced by developers when working with the fragment lifecycle, fragment transactions, or layout-related misconfigurations. In this guide, we’ll explore why your Kotlin fragments might not be rendering as expected and how to fix it with a complete working example.

Kotlin Fragments Not Displaying

Some of the common causes include:

  • Using the wrong container or not using FragmentContainerView
  • Not committing fragment transactions properly
  • Lifecycle issues between Activity and Fragment
  • Improper use of FragmentManager

Let’s go step-by-step with a working Kotlin example to display a fragment correctly in an activity.

MainActivity.kt

package com.example.myapp

import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
import com.example.myapp.databinding.ActivityMainBinding

class MainActivity : AppCompatActivity() {

    private lateinit var binding: ActivityMainBinding

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(binding.root)

        // Check if fragment already exists
        if (savedInstanceState == null) {
            val fragment = SampleFragment()
            supportFragmentManager.beginTransaction()
                .replace(R.id.fragment_container_view, fragment)
                .commit()
        }
    }
}

SampleFragment.kt

package com.example.myapp

import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.fragment.app.Fragment
import com.example.myapp.databinding.FragmentSampleBinding

class SampleFragment : Fragment() {

    private var _binding: FragmentSampleBinding? = null
    private val binding get() = _binding!!

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {
        _binding = FragmentSampleBinding.inflate(inflater, container, false)
        return binding.root
    }

    override fun onDestroyView() {
        super.onDestroyView()
        _binding = null
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.fragment.app.FragmentContainerView
        android:id="@+id/fragment_container_view"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

fragment_sample.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:gravity="center">

    <TextView
        android:id="@+id/sample_text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Fragment Loaded Successfully!"
        android:textSize="18sp" />

</LinearLayout>

By using FragmentContainerView instead of a regular FrameLayout, and ensuring commit() is called without delay, the fragment will load correctly. For additional reference on fragment best practices, visit the official Android documentation.

rysasahrial

Leave a Reply

Your email address will not be published. Required fields are marked *