Android – View Binding

agulevski10
Jan 1, 2021
1 min read

View binding is a feature that allows you to more easily write code that interacts with views. Once view binding is enabled in a module, it generates a binding class for each XML layout file present in that module.

Add this in to app module build.gradle in android under buildFeatures:

JavaScript

android{ ... buildFeatures { viewBinding = true } }

android{

...

buildFeatures {

viewBinding = true

}

Create layout file – activity_main.xml:

XHTML

<?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" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/activityMainLayout" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity"> <TextView android:id="@+id/textLabel" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello world" android:textSize="20sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> </androidx.constraintlayout.widget.ConstraintLayout>

<?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"

xmlns:tools="http://schemas.android.com/tools"

android:id="@+id/activityMainLayout"

android:layout_width="match_parent"

android:layout_height="match_parent"

tools:context=".MainActivity">

<TextView

android:id="@+id/textLabel"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="Hello world"

android:textSize="20sp"

app:layout_constraintBottom_toBottomOf="parent"

app:layout_constraintLeft_toLeftOf="parent"

app:layout_constraintRight_toRightOf="parent"

app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

In the MainActivity we need to declare this layout root element as class:

Java

private ActivityMainBinding binding;

note: the class name for this binding to work needs to have the layout file name and word binding together with camel case. In our case activity_main + binding = ActivityMainBinding class name.

and to set in in onCreate():

Java

@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); binding = ActivityMainBinding.inflate(getLayoutInflater()); setContentView(binding.getRoot()); }