android calendar example

different files

MainActivity.java:

package com.sunmeat.calendar;

import android.Manifest;
import android.content.ContentResolver;
import android.content.ContentValues;
import android.content.Context;
import android.content.pm.PackageManager;
import android.os.Build;
import android.os.Bundle;
import android.provider.CalendarContract;
import android.widget.Button;
import android.widget.DatePicker;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.annotation.RequiresApi;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;

import java.util.Calendar;
import java.util.TimeZone;

public class MainActivity extends AppCompatActivity {

    private static final int PERMISSION_REQUEST_WRITE_CALENDAR = 1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Button addBirthdayButton = findViewById(R.id.addBirthdayButton);
        DatePicker datePicker = findViewById(R.id.datePicker);

        addBirthdayButton.setOnClickListener(view -> requestCalendarPermissionAndAddEvent(datePicker));
    }

    @RequiresApi(api = Build.VERSION_CODES.N)
    private void requestCalendarPermissionAndAddEvent(DatePicker datePicker) {
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_CALENDAR)
                != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(this,
                    new String[]{Manifest.permission.WRITE_CALENDAR},
                    PERMISSION_REQUEST_WRITE_CALENDAR);
        } else {
            addBirthdayToCalendar(datePicker);
        }
    }

    @RequiresApi(api = Build.VERSION_CODES.N)
    private void addBirthdayToCalendar(DatePicker datePicker) {
        int year = datePicker.getYear();
        int month = datePicker.getMonth();
        int day = datePicker.getDayOfMonth();

        Calendar birthdayDate = Calendar.getInstance();
        birthdayDate.set(year, month, day);

        long startMillis = birthdayDate.getTimeInMillis();
        long endMillis = startMillis + 60 * 60 * 1000; // 1 hour

        ContentResolver contentResolver = getContentResolver();
        ContentValues values = new ContentValues();

        values.put(CalendarContract.Events.DTSTART, startMillis);
        values.put(CalendarContract.Events.DTEND, endMillis);
        values.put(CalendarContract.Events.TITLE, "День Рождения");
        values.put(CalendarContract.Events.DESCRIPTION, "Событие: День Рождения");
        values.put(CalendarContract.Events.CALENDAR_ID, 1); // ID календаря, чаще всего 1
        values.put(CalendarContract.Events.EVENT_TIMEZONE, TimeZone.getDefault().getID());

        getContentResolver().insert(CalendarContract.Events.CONTENT_URI, values);

        Toast.makeText(this, "Событие Дня Рождения добавлено в календарь", Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        if (requestCode == PERMISSION_REQUEST_WRITE_CALENDAR) {
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                addBirthdayToCalendar(findViewById(R.id.datePicker));
            } else {
                Toast.makeText(this, "Разрешение на запись в календарь отклонено", Toast.LENGTH_SHORT).show();
            }
        }
    }
}

/////////////////////////////////////// выбор даты + открытие стандартного приложения
/* import android.content.Intent;
import android.os.Bundle;
import android.provider.CalendarContract;
import android.view.View;
import android.widget.Button;
import android.widget.DatePicker;

import androidx.appcompat.app.AppCompatActivity;

import java.util.Calendar;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Button addBirthdayButton = findViewById(R.id.addBirthdayButton);
        DatePicker datePicker = findViewById(R.id.datePicker);

        addBirthdayButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                addBirthdayToCalendar(datePicker);
            }
        });
    }

    private void addBirthdayToCalendar(DatePicker datePicker) {
        int year = datePicker.getYear();
        int month = datePicker.getMonth();
        int day = datePicker.getDayOfMonth();

        Calendar birthdayDate = Calendar.getInstance();
        birthdayDate.set(Calendar.YEAR, year);
        birthdayDate.set(Calendar.MONTH, month);
        birthdayDate.set(Calendar.DAY_OF_MONTH, day);

        Intent intent = new Intent(Intent.ACTION_INSERT)
                .setData(CalendarContract.Events.CONTENT_URI)
                .putExtra(CalendarContract.Events.TITLE, "День Рождения")
                .putExtra(CalendarContract.Events.DESCRIPTION, "Событие: День Рождения")
                .putExtra(CalendarContract.EXTRA_EVENT_BEGIN_TIME, birthdayDate.getTimeInMillis())
                .putExtra(CalendarContract.EXTRA_EVENT_ALL_DAY, true);

        startActivity(intent);
    }
} */

============================================================================================================

activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/addBirthdayButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="16dp"
        android:text="Добавить День Рождения в календарь" />

    <DatePicker
        android:id="@+id/datePicker"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/addBirthdayButton"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="16dp" />
</RelativeLayout>

============================================================================================================

AndroidManifest.xml:

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