c#_csv_to_grid.cs

/*
#!/usr/bin/mcs -r:System.Windows.Forms.dll -r:System.Drawing.dll
set path=C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\MSBuild\15.0\Bin\Roslyn\;%path%
csc.exe -debug+ -target:winexe -r:System.Windows.Forms.dll -r:System.Drawing.dll c#_winforms_base.cs
*/

using System;
using System.Windows.Forms;
using System.Drawing;
using System.Data;
using System.Collections.Generic; // for List()
using System.Text;
using System.Text.RegularExpressions;

using System.IO;
//using System.Text.RegularExpressions;

public class Program
{
    static MenuStrip strip = new MenuStrip();
    static StatusStrip statusStrip = new StatusStrip();
    static ToolStripStatusLabel statusLabel = new ToolStripStatusLabel();
    static ToolStripComboBox separator = new ToolStripComboBox();
    static ToolStripTextBox filter = new ToolStripTextBox();
    static DataGridView dataGridView = new DataGridView();

    [STAThread]
    public static void Main()
    {
        try
        {

        var f = new Form();
            f.Text = System.Reflection.Assembly.GetExecutingAssembly().GetName().Name;
            f.Size = new Size(500, 400);

            ToolStripMenuItem fileItem = new ToolStripMenuItem("&Fájl");
            var openFileMenuItem = fileItem.DropDownItems.Add("&Megnyitás");
                openFileMenuItem.Click += new EventHandler (Open);
            var saveFileMenuItem = fileItem.DropDownItems.Add("M&entés");
                saveFileMenuItem.Enabled = false;
                // username.Click += (s, e) => SomeTextBox.Text = "...";
            var quitMenuItem = fileItem.DropDownItems.Add("&Kilépés");
                quitMenuItem.Click += new EventHandler ( Exit );
            strip.Items.Add(fileItem);

            separator.Items.AddRange( new object[] { ",", ";"} );
            separator.Text = ";";
            separator.Width = 30;
            strip.Items.AddRange( new ToolStripItem[] { separator });

            filter.Text = ".*";
            strip.Items.AddRange( new ToolStripItem[] { filter });

            f.Controls.Add(strip);

            statusStrip.Items.AddRange(new ToolStripItem[] {statusLabel});
            statusStrip.LayoutStyle = ToolStripLayoutStyle.HorizontalStackWithOverflow;
            f.Controls.Add(statusStrip);

            dataGridView.Location = new Point(5, 30);
            dataGridView.Size = new Size(f.Width-25, f.Height-95);
            dataGridView.Anchor = ( AnchorStyles.Top | AnchorStyles.Bottom | AnchorStyles.Left | AnchorStyles.Right );
            dataGridView.ReadOnly = true;
            dataGridView.MultiSelect = true;
            dataGridView.AllowUserToAddRows = false;
            dataGridView.AutoResizeColumns();
            dataGridView.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.AllCells;
            f.Controls.Add(dataGridView);
            //dataGridView.Dock = DockStyle.Fill; // Ez valószínűleg csak MainMenu tipus esetén működik.

            Application.Run(f);

        }
        catch (Exception e)
        {
            statusLabel.Text = e.Message;
        }
    }


    static private void Exit (object sender, EventArgs e)
    {
        Application.Exit();
    }

    static private void Open (object sender, EventArgs e)
    {
        OpenFileDialog openDialog = new OpenFileDialog();
        openDialog.Title = "Select A File";
        openDialog.Filter = "Text Files (*.csv)|*.csv" + "|" +
                            "All Files (*.*)|*.*";
        openDialog.InitialDirectory = Environment.CurrentDirectory;
        if ( openDialog.ShowDialog() == DialogResult.OK )
        {
            statusLabel.Text = openDialog.FileName;
            try
            {

                //dataGridView.AutoGenerateColumns = false;
                dataGridView.DataSource = null;
                //dataTable.Clear();
                //dataTable.Reset();
                DataTable dataTable = new DataTable();

                string s = "";
                ulong i = 0;
                var regexp = new Regex(filter.Text);
                using (StreamReader sr = new StreamReader(statusLabel.Text,Encoding.GetEncoding("Windows-1250"),false,64*1024*1024)) // .NET 5-től nem jó
                //using (StreamReader sr = new StreamReader(statusLabel.Text,Encoding.GetEncoding("UTF-8"),false,64*1024*1024)) //
                // using (StreamReader sr = new StreamReader(statusLabel.Text, Encoding.UTF8, false, 64 * 1024 * 1024)) // .NET5
                {
                    s = String.Empty;
                    while ((s = sr.ReadLine()) != null)
                    {
                        if ( i++ == 0 )
                        {
                            foreach ( var data in s.Split(separator.Text[0]) )
                            {
                                dataTable.Columns.Add(data,typeof(string));
                            }
                        }
                        else
                        {
                            if ( regexp.Match(s).Success )
                                dataTable.Rows.Add(s.Split(separator.Text[0]));
                        }
                        statusLabel.Text = i.ToString();
                        statusStrip.Update();
                    }
                }

                dataGridView.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.None; // Enélkül folyamatosan újraszámol, igazítja a cellákat, ami sokszorosára növeli az időigényt.
                dataGridView.DataSource = dataTable;

                foreach (DataGridViewRow dgrow in dataGridView.Rows)
                {
                    dgrow.HeaderCell.Value = String.Format("{0}", dgrow.Index + 1);
                    dgrow.HeaderCell.Style.Alignment = DataGridViewContentAlignment.MiddleCenter;
                }
                dataGridView.AutoResizeRowHeadersWidth( DataGridViewRowHeadersWidthSizeMode.AutoSizeToAllHeaders );
                dataGridView.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.AllCells;
                //dataGridView.Update();
                //dataGridView.Refresh();
                statusLabel.Text = dataTable.Rows.Count.ToString();
                //DateTime.Now.ToString("h:mm:ss tt");

            }
            catch (Exception e2)
            {
                //System.Diagnostics.Debug.WriteLine(e2.Message);
                statusLabel.Text = e2.Message;
                statusStrip.Update();
            }
        }


    }

}