I am trying implement the basic example from here, and got this code:

class MainActivity : AppCompatActivity() {
    private lateinit var imageView: ImageView

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        val binding = ActivityMainBinding.inflate(layoutInflater)
        imageView = binding.imageView
        binding.button1.setOnClickListener {
            this.dispatchTakePictureIntent()
        }
        setContentView(R.layout.activity_main)
    }

    private fun dispatchTakePictureIntent() {
        val takePictureIntent = Intent(MediaStore.ACTION_IMAGE_CAPTURE)
        try {
            startActivityForResult(takePictureIntent, REQUEST_IMAGE_CAPTURE)
        } catch (e: ActivityNotFoundException) {
            println(e.stackTrace)
        }
    }

    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
        super.onActivityResult(requestCode, resultCode, data)

        if (requestCode == REQUEST_IMAGE_CAPTURE && resultCode == RESULT_OK) {
            val imageBitmap = data?.extras?.get("data") as Bitmap
            imageView.setImageBitmap(imageBitmap)
        }
    }

}

the code builds and I can deploy and run the app in my phone, but when I click in the button I set the click listener, nothing happens. Anyone can tell what's wrong here?

ps.: here the layout related to this activity, if needed:

<?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:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <ImageView
        android:id="@ id/imageView"
        android:layout_width="348dp"
        android:layout_height="177dp"
        android:layout_marginStart="38dp"
        android:layout_marginTop="151dp"
        android:layout_marginEnd="25dp"
        android:background="#0091EA"
        android:contentDescription="@string/todo"
        app:layout_constraintBottom_toTopOf="@ id/button4"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@ id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="158dp"
        android:layout_marginTop="100dp"
        android:layout_marginEnd="151dp"
        android:layout_marginBottom="264dp"
        android:text="@string/take_pic"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@ id/button4" />

</androidx.constraintlayout.widget.ConstraintLayout>

CodePudding user response：

You have inflated a layout via View Binding, and the button in that layout is the one you added a click listener to.

However, you never used the layout that you inflated. Instead, you called

setContentView(R.layout.activity_main)

which inflates a new copy of the layout with no connection to the instance you inflated with View Binding. Replace this line with

setContentView(binding.root)

CodePudding user response：

Did you give the application permission to read from storage?

 <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />