using (var file = new StreamWriter("file.txt"))
{
    file.WriteLine("Привет, мир!");
}

StreamWriter file = new StreamWriter("file.txt");
try
{
    file.WriteLine("Привет, мир!");
}
finally
{
    if (file != null)
        file.Dispose(); // Автоматический вызов Dispose()
}

await using (var file = new AsyncResource())
{
    await file.DoSomethingAsync();
}

var file = new AsyncResource();
try
{
    await file.DoSomethingAsync();
}
finally
{
    if (file != null)
        await file.DisposeAsync();
}

Action<string> showMessage = message => Console.WriteLine(message);
showMessage("Привет!"); // Выведет: Привет!

Func<int, int, int> sum = (a, b) => a + b;
int result = sum(5, 3); 
Console.WriteLine(result); // 8

using (SqlCommand cmd = new SqlCommand("SELECT * FROM Users WHERE Username = @username", conn))
{
    cmd.Parameters.AddWithValue("@username", username);
    // Выполнение команды
}

string safeContent = Microsoft.Security.Application.Encoder.HtmlEncode(userInput);

[Authorize(Roles = "Admin")]
public IActionResult AdminOnly()
{
    return View();
}

<form asp-action="Create">
    <input type="hidden" name="__RequestVerificationToken" value="@Antiforgery.GetTokens(HttpContext).RequestToken" />
    <!-- Другие поля формы -->
</form>

using (Aes aes = Aes.Create())
{
    aes.Key = key;
    aes.IV = iv;
    // Шифрование данных
}

_logger.LogInformation("User {UserId} logged in.", userId);

try
{
    // Код, который может вызвать исключение
}
catch (Exception ex)
{
    _logger.LogError(ex, "Произошла ошибка.");
    return View("Error");
}

var connectionString = Configuration["ConnectionStrings:DefaultConnection"];

using System;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        PriorityQueue<int, int> minHeap = new PriorityQueue<int, int>();

        minHeap.Enqueue(5, 5);
        minHeap.Enqueue(3, 3);
        minHeap.Enqueue(8, 8);
        minHeap.Enqueue(1, 1);

        while (minHeap.Count > 0)
        {
            Console.WriteLine(minHeap.Dequeue()); // Выведет: 1, 3, 5, 8
        }
    }
}

int num = 123;
object obj = num;  // Boxing

object obj = 123;  // Boxing
int num = (int)obj;  // Unboxing

<TextBlock Text="{Binding UserName}" />

<TextBox Text="{Binding UserName, Mode=TwoWay}" />

<button @onclick="IncrementCount">Добавить</button>

@code {
    private int count = 0;
    private void IncrementCount() => count++;
}

<Button Content="Сохранить" Command="{Binding SaveCommand}" />

<ListBox ItemsSource="{Binding Users}" DisplayMemberPath="Name" />