Pliki CSV w C# - Najważniejsze Informacje

Czym są pliki CSV?

Zadanie do zrealizowania

• email,
• imię,
• datę dodania,
• informacje o tym, czy adres e-mail został potwierdzony

• Dodania nowego klienta ze wszystkimi danymi z samej aplikacji.
• Zapis danych, tak żeby dane były dostępne po zamknięciu i ponownym uruchomieniu aplikacji.
• Podgląd tych danych w aplikacji.
• I właśnie możliwość eksportowania danych do formatu CSV, tak żeby można było je podejrzeć w Excelu.

Projekt

public class Client
{
    public string Email { get; set; }
    public string Name { get; set; }
    public DateTime AddedDate { get; set; }
    public bool IsConfirmed { get; set; }
}

public partial class Form1 : Form
{
    private BindingList<Client> _clients = new BindingList<Client>();

    public Form1()
    {
        InitializeComponent();

        dgvClients.DataSource = _clients;
    }

    private void btnAdd_Click(object sender, EventArgs e)
    {
        var client = new Client
        {
            Email = tbEmail.Text,
            Name = tbName.Text,
            AddedDate = dtpAddedDate.Value,
            IsConfirmed = cbIsConfirmed.Checked
        };

        _clients.Add(client);

        ClearData();
    }

    private void ClearData()
    {
        tbEmail.Text = "";
        tbName.Text = "";
        dtpAddedDate.Value = DateTime.Now;
        cbIsConfirmed.Checked = false;
    }

    private void btnSave_Click(object sender, EventArgs e)
    {
    }
}

Instalacja biblioteki

Zapis danych do pliku CSV

private void btnSave_Click(object sender, EventArgs e)
{
    using var writer = new StreamWriter(ClientsFileName);
    using var csv = new CsvWriter(writer, CultureInfo.InvariantCulture);
    csv.WriteRecords(_clients);
}

private const string ClientsFileName = "clients.csv"

private void btnSave_Click(object sender, EventArgs e)
{
    using var stream = File.Open(ClientsFileName, FileMode.Append);
    using var writer = new StreamWriter(stream);
    using var csv = new CsvWriter(writer, CultureInfo.InvariantCulture);
    csv.WriteRecords(_clients);
}

private void btnSave_Click(object sender, EventArgs e)
{
    var configPersons = new CsvConfiguration(CultureInfo.InvariantCulture)
    {
        HasHeaderRecord = false
    };

    using var stream = File.Open(ClientsFileName, FileMode.Append);
    using var writer = new StreamWriter(stream);
    using var csv = new CsvWriter(writer, configPersons);
    csv.WriteRecords(_clients);
}

private void btnSave_Click(object sender, EventArgs e)
{
    using var writer = new StreamWriter(ClientsFileName);
    using var csv = new CsvWriter(writer, CultureInfo.InvariantCulture);
    csv.WriteRecords(_clients);
}

Mapowanie

public class Client
{
    [Name("E-mail")]
    [Index(2)]
    public string Email { get; set; }

    [Name("Imię")]
    [Index(1)]
    public string Name { get; set; }

    [Format("dd-MM-yyyy")]
    [Name("Data dodania")]
    [Index(0)]
    public DateTime AddedDate { get; set; }

    [Name("Czy potwierdzony")]
    [Index(3)]
    public bool IsConfirmed { get; set; }
}

public class ClientMap : ClassMap<Client>
{
    public ClientMap()
    {
        Map(p => p.Email)
            .Index(2)
            .Name("E-mail");

        Map(p => p.Name)
            .Index(1)
            .Name("Imię");

        Map(p => p.AddedDate)
            .Name("Data dodania")
            .TypeConverterOption.Format("dd-MM-yyyy")
            .Index(0);

        Map(p => p.IsConfirmed)
            .Name("Czy potwierdzony")
            .Index(3);
    }
}

public class Client
{
    public string Email { get; set; }
    public string Name { get; set; }
    public DateTime AddedDate { get; set; }
    public bool IsConfirmed { get; set; }
}

private void btnSave_Click(object sender, EventArgs e)
{
    using var writer = new StreamWriter(ClientsFileName);
    using var csv = new CsvWriter(writer, CultureInfo.InvariantCulture);
    csv.Context.RegisterClassMap<ClientMap>();
    csv.WriteRecords(_clients);
}

Odczyt danych z pliku CSV

private void Form1_Load(object sender, EventArgs e)
{
}

private void Form1_Load(object sender, EventArgs e)
{
    using var reader = new StreamReader(ClientsFileName);
    using var csv = new CsvReader(reader, CultureInfo.InvariantCulture);
    csv.Context.RegisterClassMap<ClientMap>();
    var clients = csv.GetRecords<Client>().ToList();

    FillTable(clients);
}

private void FillTable(IList<Client> clients)
{
    _clients.Clear();

    if (clients == null || !clients.Any())
        return;

    foreach (var client in clients)
        _clients.Add(client);
}

public Form1()
{
    InitializeComponent();

    File.Create(ClientsFileName).Close();

    dgvClients.DataSource = _clients;
}