CXml1.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Xml;
using System.Xml.Linq;
using System.IO;


namespace _45._1
{
    public static class CXml1
    {

        public static int A1;   // pocet vyskytu point
        public static int A2;   // pocet vyskytu line


        public static void mvINit()
        {
            A1 = 0;
            A2 = 0;
        }

        public static void mvReXml()
        {
            XmlReader xmlReader1;
            string lsAtrCurr1;
            int pt_index;
            int coord_x;
            int coord_y;
            int coord_z;

            int ln_index;
            int point_1;
            int point_2;



            xmlReader1 = XmlReader.Create("ingraf_cv451a.xml");

            while (xmlReader1.Read())
            { //====== cyklus
                if (xmlReader1.NodeType == XmlNodeType.Element)
                {
                    //Console.WriteLine("_Elem_name: " + xmlReader1.Name);
                }

                if ((xmlReader1.NodeType == XmlNodeType.Element) && (xmlReader1.Name == "point"))
                {
                    A1++;
                    if (xmlReader1.HasAttributes)
                    { //====== ma atributy
                        lsAtrCurr1 = xmlReader1.GetAttribute("pt_index");
                        pt_index = Convert.ToInt32(lsAtrCurr1);
                        lsAtrCurr1 = xmlReader1.GetAttribute("coord_x");
                        coord_x = Convert.ToInt32(lsAtrCurr1);
                        lsAtrCurr1 = xmlReader1.GetAttribute("coord_y");
                        coord_y = Convert.ToInt32(lsAtrCurr1);
                        lsAtrCurr1 = xmlReader1.GetAttribute("coord_z");
                        coord_z = Convert.ToInt32(lsAtrCurr1);
                    }//====== ma atributy

                }

                if ((xmlReader1.NodeType == XmlNodeType.Element) && (xmlReader1.Name == "line"))
                {
                    A2++;
                    if (xmlReader1.HasAttributes)
                    { //====== ma atributy
                        lsAtrCurr1 = xmlReader1.GetAttribute("ln_index");
                        ln_index = Convert.ToInt32(lsAtrCurr1);
                        lsAtrCurr1 = xmlReader1.GetAttribute("point_1");
                        point_1 = Convert.ToInt32(lsAtrCurr1);
                        lsAtrCurr1 = xmlReader1.GetAttribute("point_2");
                        point_2 = Convert.ToInt32(lsAtrCurr1);

                    }//====== ma atributy

                }

            } //====== cyklus

            lsAtrCurr1 = "";
        }


    }
}

CAct1.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _45._1
{
    public static class CAct1
    {

        public static void mvAct(int guiid)
        {
            switch (guiid)
            {
                case 1:   //reXml
                    CXml1.mvReXml();  //cte xml soubor

                    break;
                case 2:    //Graf

                    break;
                case 3:    //Exit

                    break;
                default :    //nesmi nastat
                    break;


            }
        }



    }
}

Form1.cs
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;


namespace _45._1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void button3_Click(object sender, EventArgs e)
        {
            CAct1.mvAct(3);
        }

        private void button1_Click(object sender, EventArgs e)
        {
            CAct1.mvAct(1);

        }

        private void button2_Click(object sender, EventArgs e)
        {
            CAct1.mvAct(2);
        }
    }
}