ViewBinding

ViewBinding與DataBinding差不多但是有一些不一樣的特性
1.使用ViewBinding不用加上<layout>標籤
2.不能與XML中的數據做綁定
3.構建時會比DataBinding還快
root:布局中最外層的ViewGroup

android {
    buildFeatures {
        viewBinding true
    }
}

<TextView
    android:id="@+id/data"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Hello World!"
    android:textAppearance="@style/TextAppearance.AppCompat.Display1"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintTop_toTopOf="parent" />

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        val binding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(binding.root) 
        binding.data.text = "Hello ViewBinding"
    }
}