activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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">

    <TimePicker
        android:id="@+id/timepicker"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content">

    </TimePicker>


</RelativeLayout>

MainActivity.java

package com.example.timecount;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.widget.TimePicker;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        TimePicker tp = (TimePicker) findViewById(R.id.timepicker);
        tp.setIs24HourView(true);
        tp.setOnTimeChangedListener(new TimePicker.OnTimeChangedListener() {
            @Override
            public void onTimeChanged(TimePicker view, int hourOfDay, int minute) {
                String str = hourOfDay+"时" +minute+"分";
                Toast.makeText(MainActivity.this, str, Toast.LENGTH_SHORT).show();
            }
        });

    }
}

运行结果：