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.

Some of the common causes include:
- Using the wrong container or not using
FragmentContainerView
- Not committing fragment transactions properly
- Lifecycle issues between
Activity
andFragment
- 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.