I've done my research on memory leak when using Data Binding. Every posts said that one should assign null to binding object to resolve this issue. However, it just doesn't work.
I've created two identical Fragments with a single Activity. Each Fragment includes a button which can be used to navigate to one another.
To reproduce this issue, click the button repeatedly, LeakCanary will pop up the memory leak warning. (However, the issue does not occur when clicking the buttons "programmatically")
Repro
LeakCanary
Code
The following is the code of my Fragments. (Two fragments are identical)
FirstFragment.kt
class FirstFragment : Fragment() {
private var _binding: FragmentFirstBinding? = null
val binding get() = _binding!!
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?,
): View {
_binding = FragmentFirstBinding.inflate(layoutInflater, container, false)
return binding.root
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
binding.lifecycleOwner = viewLifecycleOwner
binding.btnFirst.setOnClickListener {
findNavController().navigate(R.id.action_to_second)
}
}
override fun onDestroyView() {
super.onDestroyView()
_binding = null
}
}
fragment_first.xml
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools">
<data>
</data>
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".FirstFragment">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="@string/first_fragment" />
<com.google.android.material.button.MaterialButton
android:id="@+id/btn_first"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:text="To second" />
</FrameLayout>
</layout>
SecondFragment.kt
class SecondFragment : Fragment() {
private var _binding: FragmentSecondBinding? = null
val binding get() = _binding!!
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?,
): View {
_binding = FragmentSecondBinding.inflate(layoutInflater, container, false)
return binding.root
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
binding.lifecycleOwner = viewLifecycleOwner
binding.btnSecond.setOnClickListener {
findNavController().navigate(R.id.action_to_first)
}
}
override fun onDestroyView() {
super.onDestroyView()
_binding = null
}
}
fragment_second.xml
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools">
<data>
</data>
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".SecondFragment">
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="@string/second_fragment" />
<com.google.android.material.button.MaterialButton
android:id="@+id/btn_second"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:text="To first" />
</FrameLayout>
</layout>
I've also created a repo in case someone want to try it out.
Let me know if I can provide any further information. Thanks!

