using System;
 
namespace HelloWorld {
    class Program {
        static void Main(string[] args) {
            Console.WriteLine("Hello, World!");
        }
    }
}

public class Person {
    private string name;
    public int Age { get; set; }
 
    public Person(string name, int age) {
        this.name = name;
        Age = age;
    }
 
    public void Speak() {
        Console.WriteLine($"Hello, my name is {name} and I am {Age} years old.");
    }
}

public interface IGreetable {
    void Greet();
}
 
public class FriendlyPerson : IGreetable {
    public void Greet() {
        Console.WriteLine("Hi there! Nice to meet you!");
    }
}

public class Animal {
    public void Eat() {
        Console.WriteLine("Eating...");
    }
}
 
public class Dog : Animal {
    public void Bark() {
        Console.WriteLine("Barking...");
    }
}

public class Animal {
    public virtual void Speak() {
        Console.WriteLine("Animal sound");
    }
}
 
public class Dog : Animal {
    public override void Speak() {
        Console.WriteLine("Woof!");
    }
}

public class ResourceHolder : IDisposable {
    public void Dispose() {
        // Clean up resources here
    }
}

int number = 10;
if (number > 5) {
    Console.WriteLine("Number is greater than 5");
}

Number is greater than 5 

int number = 3;
if (number > 5) {
    Console.WriteLine("Number is greater than 5");
} else {
    Console.WriteLine("Number is 5 or less");
}

Number is 5 or less 

int number = 5;
if (number > 5) {
    Console.WriteLine("Number is greater than 5");
} else if (number == 5) {
    Console.WriteLine("Number is equal to 5");
} else {
    Console.WriteLine("Number is less than 5");
}

Number is equal to 5 

for (int i = 0; i < 5; i++) {
    Console.WriteLine("Iteration: " + i);
}

Iteration: 0
Iteration: 1
Iteration: 2
Iteration: 3
Iteration: 4

int i = 0;
while (i < 5) {
    Console.WriteLine("Iteration: " + i);
    i++;
}

Iteration: 0
Iteration: 1
Iteration: 2
Iteration: 3
Iteration: 4

int i = 0;
do {
    Console.WriteLine("Iteration: " + i);
    i++;
} while (i < 5);

Iteration: 0
Iteration: 1
Iteration: 2
Iteration: 3
Iteration: 4

int day = 3;
switch (day) {
    case 1:
        Console.WriteLine("Monday");
        break;
    case 2:
        Console.WriteLine("Tuesday");
        break;
    case 3:
        Console.WriteLine("Wednesday");
        break;
    default:
        Console.WriteLine("Other day");
        break;
}

Wednesday 

public void Greet(string name) {
    Console.WriteLine("Hello, " + name);
}
 
Greet("Alice");

Hello, Alice 

int[] numbers = {1, 2, 3, 4, 5};
foreach (int number in numbers) {
    Console.WriteLine("Number: " + number);
}

Number: 1
Number: 2
Number: 3
Number: 4
Number: 5

List<string> names = new List<string> {"Alice", "Bob", "Charlie"};
names.Add("Dave");
foreach (string name in names) {
    Console.WriteLine("Name: " + name);
}

Name: Alice
Name: Bob
Name: Charlie
Name: Dave

for (int i = 0; i < 10; i++) {
    if (i == 5) {
        break; // خروج از حلقه زمانی که i برابر 5 است
    }
    Console.WriteLine("Iteration: " + i);
}

Iteration: 0
Iteration: 1
Iteration: 2
Iteration: 3
Iteration: 4

for (int i = 0; i < 5; i++) {
    if (i == 2) {
        continue; // ادامه به تکرار بعدی بدون اجرای کدهای بعدی
    }
    Console.WriteLine("Iteration: " + i);
}

Iteration: 0
Iteration: 1
Iteration: 3
Iteration: 4

int age = 25;
string name = "Alice";
bool isStudent = true;
 
Console.WriteLine($"Name: {name}, Age: {age}, Student: {isStudent}");

Name: Alice, Age: 25, Student: True 

int a = 10;
int b = 3;
int sum = a + b;
int difference = a - b;
int product = a * b;
int quotient = a / b;
int remainder = a % b;
 
Console.WriteLine($"Sum: {sum}, Difference: {difference}, Product: {product}, Quotient: {quotient}, Remainder: {remainder}");

Sum: 13, Difference: 7, Product: 30, Quotient: 3, Remainder: 1 

double x = 9.78;
int y = (int)x; // تبدیل ضمنی از double به int
 
Console.WriteLine($"Double: {x}, Integer: {y}");

Double: 9.78, Integer: 9 

string greeting = "Hello";
string name = "World";
string message = greeting + ", " + name + "!";
Console.WriteLine(message);

Hello, World! 

string multiLineString = @"This is a 
multi-line 
string.";
Console.WriteLine(multiLineString);

This is a 
multi-line 
string.

string name = "Alice";
int age = 25;
string message = $"Name: {name}, Age: {age}";
Console.WriteLine(message);

Name: Alice, Age: 25 

string phrase = "Hello World!";
string lowerCasePhrase = phrase.ToLower();
string upperCasePhrase = phrase.ToUpper();
bool containsWorld = phrase.Contains("World");
 
Console.WriteLine($"LowerCase: {lowerCasePhrase}, UpperCase: {upperCasePhrase}, Contains 'World': {containsWorld}");

LowerCase: hello world!, UpperCase: HELLO WORLD!, Contains 'World': True 

int[] numbers = new int[5];
numbers[0] = 1;
numbers[1] = 2;
numbers[2] = 3;
numbers[3] = 4;
numbers[4] = 5;
 
foreach (int number in numbers) {
    Console.WriteLine(number);
}

1
2
3
4
5

int[] numbers = {1, 2, 3, 4, 5};
Array.Reverse(numbers);
 
foreach (int number in numbers) {
    Console.WriteLine(number);
}

5
4
3
2
1

DateTime now = DateTime.Now;
DateTime specificDate = new DateTime(2023, 10, 23);
 
Console.WriteLine($"Now: {now}, Specific Date: {specificDate}");

Now: [Current DateTime], Specific Date: 2023-10-23 00:00:00 

DateTime now = DateTime.Now;
string formattedDate = now.ToString("yyyy-MM-dd HH:mm:ss");
 
Console.WriteLine(formattedDate);

[Current Date in yyyy-MM-dd HH:mm:ss format] 

List<int> numbers = new List<int> {1, 2, 3, 4, 5};
numbers.Add(6);
numbers.Remove(3);
 
foreach (int number in numbers) {
    Console.WriteLine(number);
}

1
2
4
5
6

Dictionary<string, int> ages = new Dictionary<string, int> {
    {"Alice", 25},
    {"Bob", 30}
};
ages["Charlie"] = 35;
 
foreach (var entry in ages) {
    Console.WriteLine($"{entry.Key}: {entry.Value}");
}

Alice: 25
Bob: 30
Charlie: 35

int Factorial(int n) {
    if (n <= 1) {
        return 1;
    }
    return n * Factorial(n - 1);
}
 
Console.WriteLine($"Factorial of 5: {Factorial(5)}");

Factorial of 5: 120 

using (StreamWriter writer = new StreamWriter("test.txt")) {
    writer.WriteLine("Hello, World!");
}

try {
    int result = 10 / 0;
} catch (DivideByZeroException ex) {
    Console.WriteLine("Cannot divide by zero.");
}

Cannot divide by zero. 

public partial class MyClass {
    public void Method1() {
        Console.WriteLine("Method1");
    }
}
 
public partial class MyClass {
    public void Method2() {
        Console.WriteLine("Method2");
    }
}
 
MyClass obj = new MyClass();
obj.Method1();
obj.Method2();

Method1
Method2

public async Task DoWorkAsync() {
    await Task.Delay(1000);
    Console.WriteLine("Work completed.");
}
 
await DoWorkAsync();

Work completed. 

using System.IO;
 
// نوشتن در فایل
File.WriteAllText("example.txt", "Hello, World!");
 
// خواندن از فایل
string content = File.ReadAllText("example.txt");
Console.WriteLine(content);

Hello, World! 

using System.IO;
 
// ایجاد پوشه جدید
Directory.CreateDirectory("NewFolder");
 
// حذف پوشه
Directory.Delete("NewFolder");

using System;
 
string machineName = Environment.MachineName;
string osVersion = Environment.OSVersion.ToString();
int processorCount = Environment.ProcessorCount;
 
Console.WriteLine($"Machine Name: {machineName}, OS Version: {osVersion}, Processor Count: {processorCount}");

Machine Name: [Your Machine Name], OS Version: [Your OS Version], Processor Count: [Processor Count] 

using System.Diagnostics;
 
// راه‌اندازی یک فرآیند جدید
Process.Start("notepad.exe");
 
// بستن فرآیند با نام
foreach (var process in Process.GetProcessesByName("notepad")) {
    process.Kill();
}

using System;
using System.Runtime.InteropServices;
 
class Program {
    [DllImport("user32.dll")]
    public static extern int MessageBox(IntPtr hWnd, String text, String caption, uint type);
 
    static void Main() {
        MessageBox(IntPtr.Zero, "Hello, World!", "Hello", 0);
    }
}

using Microsoft.Win32;
 
// نوشتن در رجیستری
RegistryKey key = Registry.CurrentUser.CreateSubKey(@"Software\MyApp");
key.SetValue("Username", "Alice");
key.Close();
 
// خواندن از رجیستری
key = Registry.CurrentUser.OpenSubKey(@"Software\MyApp");
string username = (string)key.GetValue("Username");
key.Close();
 
Console.WriteLine($"Username: {username}");

Username: Alice 

using System;
 
string path = Environment.GetEnvironmentVariable("PATH");
Console.WriteLine(path);

using System;
using System.IO;
 
class Program {
    static void Main() {
        FileSystemWatcher watcher = new FileSystemWatcher();
        watcher.Path = @"C:\Your\Path\Here";
        watcher.NotifyFilter = NotifyFilters.LastWrite;
        watcher.Filter = "*.txt";
        watcher.Changed += OnChanged;
        watcher.EnableRaisingEvents = true;
 
        Console.WriteLine("Press enter to exit.");
        Console.ReadLine();
    }
 
    private static void OnChanged(object source, FileSystemEventArgs e) {
        Console.WriteLine($"File: {e.FullPath} has been modified.");
    }
}

using System;
using System.Net.Http;
using System.Threading.Tasks;
 
class Program {
    static async Task Main() {
        using (HttpClient client = new HttpClient()) {
            string response = await client.GetStringAsync("https://api.github.com");
            Console.WriteLine(response);
        }
    }
}

using System;
using System.Runtime.InteropServices;
 
class Program {
    [DllImport("kernel32.dll")]
    public static extern void GetSystemTime(ref SYSTEMTIME lpSystemTime);
 
    public struct SYSTEMTIME {
        public ushort wYear;
        public ushort wMonth;
        public ushort wDayOfWeek;
        public ushort wDay;
        public ushort wHour;
        public ushort wMinute;
        public ushort wSecond;
        public ushort wMilliseconds;
    }
 
    static void Main() {
        SYSTEMTIME stime = new SYSTEMTIME();
        GetSystemTime(ref stime);
        Console.WriteLine($"System time: {stime.wHour}:{stime.wMinute}:{stime.wSecond}");
    }
}

System time: [Current Time] 

using System;
using System.Runtime.InteropServices;
 
class Program {
    // اعلان تابع PInvoke
    [DllImport("user32.dll")]
    public static extern int MessageBox(IntPtr hWnd, String text, String caption, uint type);
 
    static void Main() {
        // استفاده از تابع MessageBox
        MessageBox(IntPtr.Zero, "Hello, World!", "Hello", 0);
    }
}

using System;
 
class Program {
    unsafe static void Main() {
        int value = 10;
        int* pValue = &value;
 
        Console.WriteLine("Value: " + value);
        Console.WriteLine("Address: " + (int)pValue);
    }
}

using System;
using System.Drawing;
using System.Windows.Forms;
 
public class CircleForm : Form {
    protected override void OnPaint(PaintEventArgs e) {
        base.OnPaint(e);
        Graphics g = e.Graphics;
        g.FillEllipse(Brushes.Blue, 50, 50, 100, 100);
    }
    
    static void Main() {
        Application.Run(new CircleForm());
    }
}

using System;
using System.Drawing;
using System.Windows.Forms;
 
public class RectangleForm : Form {
    protected override void OnPaint(PaintEventArgs e) {
        base.OnPaint(e);
        Graphics g = e.Graphics;
        g.FillRectangle(Brushes.Green, 50, 50, 200, 100);
    }
    
    static void Main() {
        Application.Run(new RectangleForm());
    }
}

using System;
using System.Drawing;
using System.Windows.Forms;
 
public class LineForm : Form {
    protected override void OnPaint(PaintEventArgs e) {
        base.OnPaint(e);
        Graphics g = e.Graphics;
        g.DrawLine(Pens.Red, 10, 10, 200, 200);
    }
    
    static void Main() {
        Application.Run(new LineForm());
    }
}

using System;
using System.Drawing;
using System.Windows.Forms;
 
public class CustomPenForm : Form {
    protected override void OnPaint(PaintEventArgs e) {
        base.OnPaint(e);
        Graphics g = e.Graphics;
        Pen pen = new Pen(Color.Blue, 5);
        g.DrawEllipse(pen, 50, 50, 100, 100);
    }
    
    static void Main() {
        Application.Run(new CustomPenForm());
    }
}

using System;
using System.Drawing;
using System.Windows.Forms;
 
public class PolygonForm : Form {
    protected override void OnPaint(PaintEventArgs e) {
        base.OnPaint(e);
        Graphics g = e.Graphics;
        Point[] points = { new Point(50, 50), new Point(100, 25), new Point(150, 50), new Point(100, 100) };
        g.FillPolygon(Brushes.Yellow, points);
    }
    
    static void Main() {
        Application.Run(new PolygonForm());
    }
}

using System;
using System.Drawing;
using System.Windows.Forms;
 
public class TextForm : Form {
    protected override void OnPaint(PaintEventArgs e) {
        base.OnPaint(e);
        Graphics g = e.Graphics;
        Font font = new Font("Arial", 24);
        g.DrawString("Hello, World!", font, Brushes.Black, 50, 50);
    }
    
    static void Main() {
        Application.Run(new TextForm());
    }
}

using System;
using System.Drawing;
using System.Windows.Forms;
 
public class ImageForm : Form {
    private Image image;
    
    public ImageForm() {
        image = Image.FromFile("path_to_your_image.jpg");
    }
    
    protected override void OnPaint(PaintEventArgs e) {
        base.OnPaint(e);
        Graphics g = e.Graphics;
        g.DrawImage(image, 50, 50);
    }
    
    static void Main() {
        Application.Run(new ImageForm());
    }
}

using System;
using SharpDX;
using SharpDX.Direct3D11;
using SharpDX.DXGI;
using SharpDX.Windows;
using Device = SharpDX.Direct3D11.Device;
 
public class DirectXForm : RenderForm {
    private Device device;
    private SwapChain swapChain;
    
    public DirectXForm() : base("DirectX Example") {
        InitializeDirectX();
    }
    
    private void InitializeDirectX() {
        var swapChainDesc = new SwapChainDescription {
            BufferCount = 1,
            ModeDescription = new ModeDescription(800, 600, new Rational(60, 1), Format.R8G8B8A8_UNorm),
            Usage = Usage.RenderTargetOutput,
            OutputHandle = this.Handle,
            SampleDescription = new SampleDescription(1, 0),
            IsWindowed = true
        };
        
        Device.CreateWithSwapChain(SharpDX.Direct3D.DriverType.Hardware, DeviceCreationFlags.None, swapChainDesc, out device, out swapChain);
    }
    
    protected override void Dispose(bool disposing) {
        swapChain.Dispose();
        device.Dispose();
        base.Dispose(disposing);
    }
    
    static void Main() {
        using (var form = new DirectXForm()) {
            RenderLoop.Run(form, () => { });
        }
    }
}

using System;
using OpenTK;
using OpenTK.Graphics;
using OpenTK.Graphics.OpenGL;
 
class Program : GameWindow {
    protected override void OnLoad(EventArgs e) {
        base.OnLoad(e);
        GL.ClearColor(Color4.CornflowerBlue);
    }
 
    protected override void OnRenderFrame(FrameEventArgs e) {
        base.OnRenderFrame(e);
        GL.Clear(ClearBufferMask.ColorBufferBit);
        SwapBuffers();
    }
 
    static void Main() {
        using (var program = new Program()) {
            program.Run(60);
        }
    }
}

using System;
using System.Drawing;
using System.Windows.Forms;
using System.Threading;
 
public class AnimationForm : Form {
    private int x = 0;
    private Timer timer;
 
    public AnimationForm() {
        this.DoubleBuffered = true;
        timer = new Timer();
        timer.Interval = 16;
        timer.Tick += UpdateFrame;
        timer.Start();
    }
 
    private void UpdateFrame(object sender, EventArgs e) {
        x += 5;
        if (x > this.ClientSize.Width) {
            x = 0;
        }
        this.Invalidate();
    }
 
    protected override void OnPaint(PaintEventArgs e) {
        base.OnPaint(e);
        Graphics g = e.Graphics;
        g.FillEllipse(Brushes.Red, x, 50, 50, 50);
    }
 
    static void Main() {
        Application.Run(new AnimationForm());
    }
}