http://kmlinux.fjfi.cvut.cz/~culikzde/pw/Properties-2019-11-18.zip

<code C#>
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using System.Drawing;
using System.ComponentModel;

namespace Properties
{
    public class Data
    {
        [DisplayName("Jmeno")]
        [Description("Jmeno objektu")]
        public string Name { get; set; }

        [Category ("Souradnice")]  
        public int X { get; set;  }

        [Category("Souradnice")]
        public int Y { get; set; }

        [Category("Souradnice")]
        [Browsable(false)]
        public int Z { get; set; }

        public Color SomeColor { get; set; }
        // public Font SomeFont { get; set; }

        public bool OK { get; set; }

        public enum Shape {  line, rectangle, ellipse };
        public Shape SomeShape { get; set; }

        // public Point EntryPoint { get; set; }
        public Size EntrySize { get; set; }

        public Data ()
        {
            SomeColor = Color.Orange;
            // SomeFont = new Font (FontFamily.GenericSansSerif, 14);
            SomeShape = Shape.line;
            // EntryPoint = new Point ();
            EntrySize = new Size();
        }

    }
}

</code>

<code C#>
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

using System.IO;
using System.Xml.Serialization;

namespace Properties
{
    public partial class Form1 : Form
    {
        Data data;

        public Form1()
        {
            InitializeComponent();

            data = new Data ();

            data.Name = "abc";
            data.X = 1;
            data.Y = 2;
            data.Z = data.Y + 1;

            propertyGrid1.SelectedObject = data;

            // using System.IO;
            // using System.Xml.Serialization;
            StringWriter f = new StringWriter ();
            XmlSerializer w = new XmlSerializer (typeof (Data));
            w.Serialize(f, data);
            string s = f.ToString();
            textBox1.AppendText(s + "\n\r");

        }

        private void SaveToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (saveFileDialog1.ShowDialog () == DialogResult.OK)
            {
                // using System.IO;
                // using System.Xml.Serialization;
                StreamWriter w = new StreamWriter(saveFileDialog1.FileName);
                XmlSerializer t = new XmlSerializer(typeof(Data));
                t.Serialize(w, data);
                w.Close();
            }
        }

        private void OpenToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (openFileDialog1.ShowDialog() == DialogResult.OK)
            {
                // using System.IO;
                // using System.Xml.Serialization;
                StreamReader r = new StreamReader (openFileDialog1.FileName);
                XmlSerializer t = new XmlSerializer(typeof(Data));
                data = (Data) t.Deserialize (r);
                propertyGrid1.SelectedObject = data;
                r.Close();
            }
        }
    }
}

</code>