一、运行效果：

二、主函数MainActivity.java:

package com.example.a074_calendarapp;

import static java.lang.String.format;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.DatePicker;
import android.widget.TextView;
import android.widget.TimePicker;

import java.text.Format;
import java.util.Calendar;

public class MainActivity extends AppCompatActivity {

    private int year,month,day,hour,minute,second;
    private TextView textView;
    private TimePicker timePicker;
    private DatePicker datePicker;
    private Button button;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(sa