MSDN – Windows Data Samples

Demonstrates how to read a UTF‑8 text file using File.OpenRead and StreamReader.

using System;
using System.IO;

class Program
{
    static void Main()
    {
        string path = @"C:\Temp\sample.txt";
        using (var reader = new StreamReader(path))
        {
            string content = reader.ReadToEnd();
            Console.WriteLine(content);
        }
    }
}

Creates a simple JSON configuration file using System.Text.Json.

using System;
using System.IO;
using System.Text.Json;

class Config
{
    public string Name { get; set; }
    public int Interval { get; set; }
}

class Program
{
    static void Main()
    {
        var cfg = new Config { Name = "SampleApp", Interval = 30 };
        string json = JsonSerializer.Serialize(cfg, new JsonSerializerOptions { WriteIndented = true });
        File.WriteAllText(@"C:\Temp\config.json", json);
        Console.WriteLine("Config written.");
    }
}

Retrieves a string value from HKCU\Software\MyApp using Microsoft.Win32.Registry.

using Microsoft.Win32;
using System;

class Program
{
    static void Main()
    {
        using (var key = Registry.CurrentUser.OpenSubKey(@"Software\MyApp"))
        {
            if (key != null)
            {
                var value = key.GetValue("InstallPath") as string;
                Console.WriteLine($"InstallPath: {value}");
            }
            else
            {
                Console.WriteLine("Key not found.");
            }
        }
    }
}

Executes a SELECT query against a local SQLite database using Microsoft.Data.Sqlite.

using Microsoft.Data.Sqlite;
using System;

class Program
{
    static void Main()
    {
        var connectionString = @"Data Source=C:\Temp\sample.db";
        using (var connection = new SqliteConnection(connectionString))
        {
            connection.Open();
            var command = connection.CreateCommand();
            command.CommandText = "SELECT Id, Name FROM Users WHERE Active = 1;";
            using (var reader = command.ExecuteReader())
            {
                while (reader.Read())
                {
                    Console.WriteLine($"{reader.GetInt32(0)} – {reader.GetString(1)}");
                }
            }
        }
    }
}

Loads an XML file and extracts values using XDocument.

using System;
using System.Linq;
using System.Xml.Linq;

class Program
{
    static void Main()
    {
        var doc = XDocument.Load(@"C:\Temp\data.xml");
        var items = doc.Root.Elements("Item")
            .Select(x => new
            {
                Id = (int)x.Element("Id"),
                Name = (string)x.Element("Name")
            });

        foreach (var item in items)
        {
            Console.WriteLine($"{item.Id}: {item.Name}");
        }
    }
}