ViewBinding not working with Intent.putExtra

Question

I am new to view binding. If I use findViewById and pass the data string data using intent's putExtra, everything is working fine. But it is not working with view Binding.

class MainActivity : AppCompatActivity() {

    companion object{
        const val camlinOrderKey = "com.example.mk_order.MainActivity.camlinOrderKey"
        const val flairOrderKey = "com.example.mk_order.MainActivity.flairOrderKey"
    }



    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        var binding: ActivityMainBinding
        binding = ActivityMainBinding.inflate(layoutInflater)

        val eT1 = findViewById<EditText>(R.id.eT1)
        // val eT2 = findViewById<EditText>(R.id.eT2)
        val btnOrder = findViewById<Button>(R.id.btnOrder)


        btnOrder.setOnClickListener {
            val reviewIntent = Intent(this, ReviewOrder::class.java)

            val camlinOrder = eT1.text.toString()
            val flairOrder = binding.eT2.text.toString()

            reviewIntent.putExtra(camlinOrderKey, camlinOrder)
            reviewIntent.putExtra(flairOrderKey, flairOrder)

            startActivity(reviewIntent)
        }
    }
}

The eT1 shows the data on new activity but eT2 is empty. There is no error. eT2 is empty. Can you help me find the error?

Answer 1

This issue occurs because you don't pass binding.root to setContentView method of activity and binding object has no reference to views in activity layout.

According to the view binding documentation :

To set up an instance of the binding class for use with an activity, perform the following steps in the activity's onCreate() method:

1. Call the static inflate() method included in the generated binding class. This creates an instance of the binding class for the activity to use.
2. Get a reference to the root view by either calling the getRoot() method or using Kotlin property syntax.
3. Pass the root view to setContentView() to make it the active view on the screen.

You should change your code to this :

class MainActivity : AppCompatActivity() {

companion object{
    const val camlinOrderKey = "com.example.mk_order.MainActivity.camlinOrderKey"
    const val flairOrderKey = "com.example.mk_order.MainActivity.flairOrderKey"
}


override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    var binding: ActivityMainBinding
    binding = ActivityMainBinding.inflate(layoutInflater)
    setContentView(binding.root)
    binding.btnOrder.setOnClickListener {
        val reviewIntent = Intent(this, ReviewOrder::class.java)
        val camlinOrder = binding.eT1.text.toString()
        val flairOrder = binding.eT2.text.toString()
        reviewIntent.putExtra(camlinOrderKey, camlinOrder)
        reviewIntent.putExtra(flairOrderKey, flairOrder)
        startActivity(reviewIntent)
    }
}}

Answer 2

You have to pass the root view to setContentView() to make it the active view on the screen. ViewBinding | Android

Instead of setContentView(R.layout.activity_main) use this setContentView(binding.root)