[Android/XML] ダイアログを表示する

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()
        setContentView(R.layout.activity_main)
        val showDialogButton: Button = findViewById(R.id.showDialogButton)

        showDialogButton.setOnClickListener {
            // Dialog表示
            MyDialogFragment().show(supportFragmentManager, "my_dialog_tag")
        }
    }
}

class MyDialogFragment : DialogFragment() {
    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        return inflater.inflate(R.layout.fragment_my_dialog, container, false)
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        val dismissButton: Button = view.findViewById(R.id.dialogDismissButton)
        val imageView: ImageView = view.findViewById(R.id.imageView)

        imageView.setImageResource(R.drawable.ic_toronto_city) // 画像は好きなものを

        // ボタンがクリックされたらダイアログを閉じる
        dismissButton.setOnClickListener {
            dismiss()
        }
    }
}

<?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">

    <Button
        android:id="@+id/showDialogButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Show My Dialog"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:padding="24dp"
    android:gravity="center"
    android:background="@drawable/rounded_background"> <TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="This is my custom dialog!"
    android:textSize="18sp"
    android:textStyle="bold"
    android:layout_marginBottom="16dp"/>

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="200dp"
        android:layout_height="200dp"
        tools:src="@tools:sample/avatars" />

    <Button
        android:id="@+id/dialogDismissButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Dismiss" />

</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <solid android:color="@android:color/white" /> <corners android:radius="16dp" />
</shape>