kotlin 時刻選択ダイアログ

TimePickerFragment.kt を作成し、MainActivity.kt で使用します。
時刻を選択したらテキストビューに選択した時刻を表示しています。

TimePickerFragment.kt


            package com.example.sampledatetimepickerdialog

import android.app.Dialog
import android.app.TimePickerDialog
import android.content.Context
import android.os.Bundle
import android.widget.TimePicker
import androidx.fragment.app.DialogFragment
import java.util.*

class TimePickerFragment : DialogFragment(), TimePickerDialog.OnTimeSetListener {   // *1
    interface Listener {
        fun onSetTime(hour: Int, minute: Int)
    }

    private lateinit var listener: Listener

    override fun onAttach(context: Context) {   // *2
        super.onAttach(context)
        when {
            parentFragment is TimePickerFragment -> listener = parentFragment as Listener
            context is Listener -> listener = context
        }
    }

    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
        val calendar = Calendar.getInstance()
        val hour = calendar.get(Calendar.HOUR)
        val minute = calendar.get(Calendar.MINUTE)

        return TimePickerDialog(activity, this, hour, minute, true) // *3
    }

    override fun onTimeSet(p0: TimePicker?, hourOfDay: Int, minute: Int) {  // *4
        listener.onSetTime(hourOfDay, minute)
    }
}

MainActivity.kt


            package com.example.sampledatetimepickerdialog

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import com.example.sampledatetimepickerdialog.databinding.ActivityMainBinding

class MainActivity : AppCompatActivity(), TimePickerFragment.Listener {    // *1
    private lateinit var binding: ActivityMainBinding
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(binding.root)

        binding.btnTimePicker.setOnClickListener {  // *2
            val timePicker = TimePickerFragment()
            timePicker.show(supportFragmentManager, "Time picker dialog")
        }
    }

    override fun onSetTime(hour: Int, minute: Int) {    // *3
        val h = hour.toString().padStart(2, '0')
        val m = minute.toString().padStart(2, '0')
        val str = "$h:$m"
        binding.txvSample.text = str
    }
}