ASP.NET Tutorial : Object Oriented Programming Concepts in C# (2025)

A fundamental paradigm in contemporary software development, object-oriented programming (OOP) arranges software design around data or objects rather than just functions and logic. OOP is a major component of C#, a flexible and strong programming language created by Microsoft that is ideal for creating scalable, maintainable, and reliable programs.

In 2025, C# continues to evolve with modern language features while keeping its core OOP principles intact. This article explores the fundamental OOP concepts in C# and highlights how they integrate with the latest language enhancements.

What is Object-Oriented Programming?

OOP is a programming model based on the concept of “objects,” which are instances of classes. Objects combine data (fields or properties) and behaviors (methods) into a single unit. This model facilitates the structuring of programs that are easier to manage, extend, and reuse.

Four Core OOP Principles

1. Encapsulation
2. Inheritance
3. Polymorphism
4. Abstraction

Object-Oriented Concepts in C#

1. Classes and Objects

• Class: A blueprint or template that defines properties, methods, events, and other members.
• Object: An instance of a class representing a concrete entity in memory.

  public class Car
  {
      public string Make { get; set; }
      public string Model { get; set; }
  
      public void Drive()
      {
          Console.WriteLine("Driving the car");
      }
  }
  // Creating an object of Car
  Car myCar = new Car
  {
      Make = "Tesla",
      Model = "Model S"
  };
  myCar.Drive();

In C#, classes define both data and behavior. Objects are created from these classes to perform real tasks.

2. Encapsulation

Encapsulation refers to bundling data and methods that operate on that data within a class and restricting direct access to some of the object’s components.

Access Modifiers: public, private, protected, internal, and protected internal control visibility.

public class BankAccount
{
    private decimal balance; // Private field, not accessible outside class
    public decimal Balance
    {
        get { return balance; }
        private set { balance = value; } // Only the class can set balance
    }
    public void Deposit(decimal amount)
    {
        if (amount > 0)
        {
            Balance += amount;
        }
    }
}

Encapsulation enhances security and protects object integrity by controlling how data is accessed and modified.

3. Inheritance

• Inheritance allows a new class (derived or child class) to inherit fields, properties, and methods from an existing class (base or parent class). This promotes code reuse.

  public class Animal
  {
      public void Eat() => Console.WriteLine("Eating");
  }
  
  public class Dog : Animal
  {
      public void Bark() => Console.WriteLine("Barking");
  }
  
  Dog dog = new Dog();
  dog.Eat();  // Inherited from Animal
  dog.Bark();

• C# supports single inheritance (a class can inherit only from one base class).
• Multiple inheritance of interfaces is supported, providing flexibility.

4. Polymorphism

Polymorphism allows methods to have multiple forms. In C#, this is primarily achieved via.

• Method Overloading: Same method name, different parameters.
• Method Overriding: A derived class provides a specific implementation of a base class method using the virtual and override keywords.
• Interface Implementation: Different classes implement the same interface in different ways.

  public class Shape
  {
      public virtual void Draw()
      {
          Console.WriteLine("Drawing Shape");
      }
  }
  public class Circle : Shape
  {
      public override void Draw()
      {
          Console.WriteLine("Drawing Circle");
      }
  }
  Shape shape = new Circle();
  shape.Draw();  // Output: Drawing Circle (runtime polymorphism)

5. Abstraction

Abstraction hides the complex implementation details and shows only the necessary features of an object. C# achieves abstraction via.

• Abstract Classes: These cannot be instantiated and can have abstract methods that derived classes must implement.
• Interfaces: Define a contract without implementation.

  public abstract class Vehicle
  {
      public abstract void Start();
  }
  public class Bike : Vehicle
  {
      public override void Start()
      {
          Console.WriteLine("Bike started");
      }
  }

New and Modern OOP Features in C# (2025)

C# has evolved significantly, with newer versions introducing features that complement OOP.

Records and Immutable Types

Introduced in C# 9 and enhanced since records are reference types with value-based equality and immutability by default.

public record Person(string FirstName, string LastName);

Records emphasize immutability, a trend in modern programming, which helps facilitate safer multi-threaded and functional-style programming.

Pattern Matching

Pattern matching enables more precise and concise handling of objects based on their type or structure, which is particularly helpful in polymorphic scenarios.

if (obj is Circle c)
{
    c.Draw();
}

Default Interface Methods

Interfaces can now contain default implementations, enabling interface evolution without breaking existing implementations.

public interface ILogger
{
    void Log(string message);
    void LogError(string error) => Log($"Error: {error}");
}

Best Practices for OOP in C# (2025)

• Favor Composition over Inheritance: Use object composition to build flexible systems.
• Use Interfaces to Define Contracts: Promotes loose coupling.
• Leverage Encapsulation for Data Protection: Use appropriate access modifiers.
• Prefer Immutable Objects: Utilize record types and readonly fields.
• Keep Methods Small and Focused: Single responsibility principle (SRP).
• Utilize Modern Language Features: Such as pattern matching and default interface methods for cleaner code.

Conclusion

Object-oriented programming remains a cornerstone of C# programming in 2025, enriched by modern features that make it more expressive, safer, and easier to maintain. Understanding OOP concepts, including encapsulation, inheritance, polymorphism, and abstraction, alongside recent language enhancements, empowers developers to build scalable, maintainable, and performant applications.

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An Introduction to Hangfire Integration in.NET 8

An open-source library called Hangfire is used in.NET applications to process jobs in the background. It enables you to carry out lengthy operations, such processing photos, sending emails, or any other work, asynchronously without interfering with the main request thread. Hangfire manages job persistence, retries, and scheduling to maintain the responsiveness of your application while guaranteeing the reliable execution of crucial background operations. 

Hangfire supports several types of jobs.

• Fire-and-Forget Jobs: Executed only once immediately after creation.
• Delayed Jobs: Scheduled to run after a specified delay.
• Recurring Jobs: Run according to a defined schedule (e.g., every day at a particular time).
• Continuation Jobs: Triggered when their parent job completes.

Prerequisites

Before you begin, ensure you have,

• .NET 8 SDK installed.
• A code editor (Visual Studio or VS Code).
• SQL Server or LocalDB for job storage.
• Basic knowledge of C# and ASP.NET Core.

Setting Up the Sample Project

1. Create a New Minimal API Project

Open your terminal.

dotnet new web -n HangfireSample

2. Add Hangfire NuGet Packages

Navigate to your project folder and run.

cd HangfireSample
dotnet add package Hangfire.AspNetCore
dotnet add package Hangfire.SqlServer
dotnet add Microsoft.Data.SqlClient

3. Configure the Database

Update appsettings.json with your connection string. For example, using LocalDB.

{
  "ConnectionStrings": {
    "HangfireConnection": "Server=Instance;Database=Your_DB;Integrated Security=True;TrustServerCertificate=true;"
  },
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft": "Warning",
      "Microsoft.Hosting.Lifetime": "Information"
    }
  }
}

Hangfire will automatically create the necessary tables.

Implementing Hangfire in .NET 8

Replace the contents of Program.cs with the following code.

using Hangfire;
using Hangfire.SqlServer;

var builder = WebApplication.CreateBuilder(args);

// Configure Hangfire to use SQL Server storage.
builder.Services.AddHangfire(config =>
{
    config.UseSqlServerStorage(builder.Configuration.GetConnectionString("HangfireConnection"));
});

// Start the Hangfire Server to process background jobs.
builder.Services.AddHangfireServer();

// (Optional) Add Swagger for API testing.
builder.Services.AddEndpointsApiExplorer();

var app = builder.Build();

// Use Swagger UI in development mode.
// Expose the Hangfire Dashboard at /hangfire (be sure to secure this in production).
app.UseHangfireDashboard();

// Root endpoint to test basic connectivity.
app.MapGet("/", () => "Hello World from .NET 8 and Hangfire!");

// Endpoint to enqueue a fire-and-forget job.
app.MapGet("/enqueue", (IBackgroundJobClient backgroundJobs) =>
{
    backgroundJobs.Enqueue(() => Console.WriteLine("Hangfire Fire-and-Forget Job executed!"));
    return Results.Ok("Background job has been enqueued.");
});
// New endpoint to schedule a delayed job (executes after 1 minute).
app.MapGet("/schedule", (IBackgroundJobClient backgroundJobs) =>
{
    backgroundJobs.Schedule(
        () => Console.WriteLine("Delayed Hangfire Job executed after 1 minute!"),
        TimeSpan.FromMinutes(1)
    );
    return Results.Ok("Delayed job scheduled to run after 1 minute.");
});

// Run the application.
app.Run();

How does This Work?

Hangfire Configuration

• AddHangfire registers Hangfire with SQL Server storage using the provided connection string.
• AddHangfireServer starts a background server to process the queued jobs.

Endpoints

• Root ("/"): Returns a basic welcome message.
• Enqueue ("/enqueue"): Uses BackgroundJob.Enqueue to immediately queue a fire-and-forget job.
• Schedule ("/schedule"): Uses BackgroundJob.Schedule to queue a job that will execute after a 1-minute delay.
• Hangfire Dashboard: Accessible at /hangfire, it provides real-time monitoring of job statuses (enqueued, processing, succeeded, or failed).

Visual Overview

Architecture Diagram

+-----------------------------+
|           Client           |
|   (Browser, Postman, etc.) |
+--------------+-------------+
               |
           HTTP Request
               |
               v
+-----------------------------+
|       .NET 8 Minimal API    |
| Endpoints:                 |
|   "/"         -> Hello World|
|   "/enqueue"  -> Enqueue    |
|   "/schedule" -> Delay      |
+--------------+-------------+
               |
     Enqueue / Schedule Command
               |
               v
+-----------------------------+
|   Hangfire Storage (SQL DB) |
+--------------+-------------+
               |
     Hangfire Server Polls
               |
               v
+-----------------------------+
| Hangfire Background Job     |
|        Processor            |
+-----------------------------+

Step-by-Step Flow

• Client Interaction: A client calls /enqueues, or /schedules to add jobs.
• Job Storage: Hangfire persists the job details in SQL Server.
• Job Processing: The Hangfire server continuously polls the queue and executes ready jobs.
• Dashboard Monitoring: The Hangfire Dashboard lets you view job states and monitor execution.

Key Terms Explained

• Fire-and-Forget Job (Enqueue): Enqueued tasks that run as soon as they’re picked up. Ideal for operations that don't require an immediate response.
• Delayed Job (Schedule): Tasks that start after a delay—useful for follow-up operations like sending reminders.
• Background Job: Any task executed asynchronously outside the main HTTP request/response cycle.
• Hangfire Server: A service that retrieves and executes background jobs from storage.
• Hangfire Dashboard: A web-based UI for monitoring job statuses. For production, secure this dashboard with proper authentication.

Running and Testing

Start the Application

dotnet run

Test the Endpoints

• Root: Navigate to http://localhost:5000/ to see "Hello World from .NET 8 and Hangfire!"
• Enqueue: Visit http://localhost:5000/enqueue to dispatch a fire-and-forget job.
• Schedule: Visit http://localhost:5000/schedule to schedule a job for execution after one minute.
• Dashboard: Open http://localhost:5000/hangfire to monitor jobs in real time.

Output Samples

Conclusion

This tutorial covered both immediate (enqueue) and delayed (schedule) job processing, showing how to incorporate Hangfire into a.NET 8 Minimal API project. Long-running processes can be transferred to background jobs to maintain the scalability and responsiveness of your application.

Then, to enhance your background processing capabilities, think about investigating repeating jobs, job continuations, or including bespoke error handling.

Have fun with your coding!

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Fixed Window vs. Sliding Window Rate Limiting in .NET

1. Fixed Window Rate Limiting (in .NET)
What it is
The Fixed Window algorithm counts requests within a strict time window (like a box of time). When the window resets, the count resets too.

Example

• Limit: 10 requests per minute.
• Every minute (e.g., from 10:00:00 to 10:01:00), a new window opens.
• If a client makes 10 requests at 10:00:05, they are allowed.
• The next request (11th) before 10:01:00 will get blocked (HTTP 429 error).
• At 10:01:00, the window resets and they can make requests again.

In .NET

options.AddSlidingWindowLimiter("sliding", opt =>
{
    opt.Window = TimeSpan.FromMinutes(1);   // 1-minute rolling window
    opt.PermitLimit = 10;                  // 10 requests allowed in the last minute
    opt.SegmentsPerWindow = 4;             // divide into 4 parts (15 seconds each)
    opt.QueueProcessingOrder = QueueProcessingOrder.OldestFirst;
    opt.QueueLimit = 2;
});

Pros

• Very simple and fast to implement.
• Good for low-traffic or non-critical APIs.

Cons

• Allows “burst traffic” at the start of the window (all 10 requests may come instantly).
• Not very "smooth" — users may hit the limit early and wait for the whole window.

2. Sliding Window Rate Limiting (in .NET)
What it is

The Sliding Window algorithm spreads the limit over a rolling period, not tied to a fixed block of time. It calculates how many requests were made in the last X minutes — no matter when the requests came.

Example

• Limit: 10 requests per minute (rolling).
• If 10 requests were made between 10:00:30 and 10:01:30, the limit applies based on that rolling window — not the wall clock.
• This avoids a sudden "burst" problem and gives a smoother, fairer limit.

In .NET

options.AddSlidingWindowLimiter("sliding", opt =>
{
    opt.Window = TimeSpan.FromMinutes(1);   // 1-minute rolling window
    opt.PermitLimit = 10;                  // 10 requests allowed in the last minute
    opt.SegmentsPerWindow = 4;             // divide into 4 parts (15 seconds each)
    opt.QueueProcessingOrder = QueueProcessingOrder.OldestFirst;
    opt.QueueLimit = 2;
});

SegmentsPerWindow: The window is divided into smaller parts (helps tracking requests better).

Pros

• Fairer and smoother — no sudden resets or spikes.
• Prevents "burst" requests at the start of each minute.

Cons

• Slightly more memory and CPU usage (to track rolling windows).
• Complex to implement manually (but .NET does this for you).

When to Use Which?

Scenario	Fixed Window	Sliding Window
Simple internal APIs	✅ Good	❌ Overkill
Public APIs used by 1000s of users	❌ Not Recommended	✅ Better
Need smooth traffic flow (e.g., payment gateway)	❌ Bad for bursts	✅ Ideal
Want easy implementation without extra load	✅ Very Easy	❌ Slightly heavy

Interview Perspective

Q: What is the key difference between Fixed and Sliding window algorithms in API Rate Limiting?

• Fixed Window resets the counter after each period (e.g., every minute).
• Sliding Window checks requests across a rolling period, making limits smoother and avoiding bursts.
• Sliding is better for high-traffic public APIs, while Fixed is good for simple, low-risk endpoints.

Real Example: Login API in .NET

Fixed Window

// Allow 5 login attempts every 60 seconds
options.AddFixedWindowLimiter("loginFixed", opt =>
{
    opt.Window = TimeSpan.FromSeconds(60);
    opt.PermitLimit = 5;
});

C#

Sliding Window

// Allow 5 login attempts in any rolling 60 seconds
options.AddSlidingWindowLimiter("loginSliding", opt =>
{
    opt.Window = TimeSpan.FromSeconds(60);
    opt.PermitLimit = 5;
    opt.SegmentsPerWindow = 6;  // 10 seconds each
});

Summary

Fixed Window	Sliding Window
Simple, less resource-hungry	Smooth, prevents burst requests
Allows initial bursts	Spreads requests over time
Good for small/private APIs	Best for public APIs, payment, login
Reset happens strictly by time	Reset happens by rolling calculation

If you want, I can

• Build a full sample .NET app demonstrating both types.
• Help you prepare exact interview answers.
• Show how to apply rate limiting per user/IP dynamically.

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Using Redis in .NET Core Applications: An Overview

Modern applications frequently employ Redis, a quick in-memory key-value store, for caching, session storage, message brokering, and pub/sub communication. It is the preferred option for creating scalable systems since it is developer-friendly, lightweight, and performant.

This article will demonstrate how to use the StackExchange if you're working on a.NET Core project and wish to incorporate Redis into your application. Redis library to carry out fundamental Redis tasks. For Windows users, Redis can be run on a server that supports it without the need for Linux or containerization.

Why Redis?

Redis offers several benefits when integrated with a .NET Core application.

1. Caching: Store frequently accessed data to improve response times and reduce database workloads.
2. Session Management: Handle user sessions efficiently in distributed systems.
3. Real-Time Events: Use Redis for pub/sub features to power real-time functionality like notifications or event-driven communication.
4. High Performance: Operates in memory, offering low-latency data access.
5. Scalable: With support for clustering and sharding, Redis is built for scalability.

Setting Up Redis

Using Redis

To connect your .NET Core app to Redis, you can run Redis either.

• Command-Line Installation: Use tools like Docker to run Redis on Linux or Windows.
• Pre-Configured Windows Alternative: If you’re on Windows, you can use a Redis-compatible server as a drop-in replacement for running Redis natively.

Note. For simplicity, this tutorial assumes Redis is running locally on localhost:6379.

Building a .NET Core Application with Redis

In this example, we’ll create a .NET Core console application that performs the following Redis operations.

1. Connect to a Redis server.
2. Perform basic key-value operations (set, get, delete).
3. Demonstrate key expiration and validation.

Step 1. Create the .NET Core Project.

1. Open a terminal and create a new project.

   dotnet new RedisIntegrationDemo

Step 2. Write the Code.

Here’s the full implementation in the Program.cs.

using System;
using StackExchange.Redis;
using System.Threading.Tasks;

namespace RedisIntegrationDemo
{
    class Program
    {
        // Connection string for Redis
        private const string RedisConnectionString = "localhost:6379";

        async static Task Main(string[] args)
        {
            Console.WriteLine("Connecting to Redis...");

            // Connect to Redis
            var redis = await ConnectionMultiplexer.ConnectAsync(RedisConnectionString);
            Console.WriteLine("Connected to Redis successfully.\n");

            // Access the Redis database
            IDatabase db = redis.GetDatabase();

            // Perform Redis operations
            Console.WriteLine("Performing Redis operations...");

            // 1. Set key-value pair
            string key = "SampleKey";
            string value = "Hello from Redis!";
            await db.StringSetAsync(key, value);
            Console.WriteLine($"Set: {key} => {value}");

            // 2. Get the value for the key
            string savedValue = await db.StringGetAsync(key);
            Console.WriteLine($"Get: {key} => {savedValue}");

            // 3. Set an expiration for the key
            TimeSpan expiryTime = TimeSpan.FromSeconds(10);
            await db.KeyExpireAsync(key, expiryTime);
            Console.WriteLine($"Set expiration for {key}: {expiryTime.TotalSeconds} seconds");

            // 4. Check key existence after expiration
            Console.WriteLine("\nWaiting for the key to expire...");
            await Task.Delay(12000); // Wait 12 seconds
            bool exists = await db.KeyExistsAsync(key);
            Console.WriteLine($"Key Exists After Expiration: {key} => {exists}");

            // Close the connection
            redis.Close();
            Console.WriteLine("\nAll Redis operations completed.");
        }
    }
}

Step 3. Run the Application.

To execute the application.

dotnet run

Expected Output

The program will connect to Redis, perform basic key-value operations, and validate key expiration. You should see output like this,

Install the StackExchange.Redis package for Redis connectivity.
dotnet add package StackExchange.Redis

How Redis Works with .NET Core?

Here’s what the application does step by step,

1. Connects to the Redis server using ConnectionMultiplexer, which manages connection pooling and server communication.
2. Performs basic commands.
   • StringSetAsync: Sets a key-value pair in Redis.
   • StringGetAsync: Gets the value of a key.
   • KeyExpireAsync: Sets an expiration time for a key.
   • KeyExistsAsync: Checks if a key exists.
3. Handles temporary in-memory storage of data with expiration.

If you’re working in a Windows environment and prefer not to install a native Redis instance or use Docker, you can use a Redis-compatible server as an alternative.

Setting Up a Redis-Compatible Server

• Install a Redis-compatible server for Windows.
• Once installed, the server typically runs on localhost:6379 by default, similar to Redis.
• Your application does not require any code changes to work with a Redis-compatible server.

Using a Redis-compatible server allows Redis functionality to run natively on Windows without relying on containers or virtualized environments.

Advantages of Using Redis in .NET Core

1. Performance: Redis operates fully in memory, enabling extremely low latency.
2. Ease of Use: Simplified API for common key-value needs, with additional data structures like lists, sets, and hashes.
3. Flexibility: Redis serves multiple purposes (e.g., caching, message queues, pub/sub).
4. Scalability: Redis supports clustering and high availability for scaling with demand.

Conclusion

Integrating Redis into your .NET Core application allows you to build high-quality, performant systems that can handle demanding workloads. With the StackExchange.Redis library, you can interact with Redis seamlessly.

Start by implementing Redis for simple caching or session management, and expand its usage to pub/sub and real-time data needs in your distributed .NET Core applications.

Happy coding and scaling!

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How to Begin Using OpenCV in .NET?

One well-known open-source framework for image processing, computer vision, and machine learning is called OpenCV (Open Source Computer Vision Library). Although OpenCV has its origins in C++, OpenCvSharp, a.NET wrapper for the OpenCV library, offers bindings that enable it to be used with ease in.NET applications.

This article is a beginner-friendly guide to getting OpenCV up and running in your .NET environment, demonstrating a basic example: loading an image and converting it to grayscale.

Prerequisites

Before diving into code, ensure you have the following set up.

1. Visual Studio (or any C# IDE of your choice).
2. .NET 5, .NET 6, or higher installed on your system.
3. Basic familiarity with C# and .NET projects.

1. Set Up OpenCvSharp in Your .NET Project

To use OpenCV in .NET, we'll install the OpenCvSharp NuGet package. This provides high-level bindings to OpenCV's functionality within a .NET application.

Steps to Install OpenCvSharp

1. Create a New .NET Project: Create a new console application named OpenCVExample.
2. Install the OpenCvSharp NuGet Packages: Run the following in your terminal or Package Manager Console in Visual Studio.

   dotnet add package OpenCvSharp4
   dotnet add package OpenCvSharp4.runtime.win  # For runtime support on Windows

2. Load an Image and Convert It to Grayscale

Now that OpenCvSharp is installed, let’s write a simple program that.

1. Loads an image.
2. Converts the image to grayscale.
3. Displays the original and grayscale images.

Here’s the complete example.

Program Code

using System;
using OpenCvSharp;

class Program
{
    static void Main(string[] args)
    {
        // Path to the image file (change this to the path of your image file)
        string imagePath = "sample.jpg";
        // Step 1: Load the image
        Mat inputImage = Cv2.ImRead(imagePath, ImreadModes.Color);
        if (inputImage.Empty())
        {
            Console.WriteLine("Failed to load the image. Check the file path.");
            return;
        }
        Console.WriteLine("Image loaded successfully!");
        // Step 2: Convert the image to grayscale
        Mat grayImage = new Mat();  // Create a new matrix to store the grayscale image
        Cv2.CvtColor(inputImage, grayImage, ColorConversionCodes.BGR2GRAY);
        Console.WriteLine("Image converted to grayscale.");
        // Step 3: Display both images (original and grayscale)
        Cv2.ImShow("Original Image", inputImage);
        Cv2.ImShow("Grayscale Image", grayImage);
        // Wait for a key press before closing the image display windows
        Console.WriteLine("Press any key to close the image windows.");
        Cv2.WaitKey();
        Cv2.DestroyAllWindows();
    }
}

3. Run the Application

Steps

1. Add the Image File: Place the image (sample.jpg) in the bin\Debug\net8.0 project folder, or specify the absolute path to your image file.
2. Build and Run the Code: Press Ctrl + F5 in Visual Studio or run from the terminal.
3. Result
   • Two separate windows will open.
     • One shows the original image.
     • One shows the grayscale version.
   • The console will display messages about the image processing status.

4. Key Methods and Concepts

Let’s break down some essential parts of the code.

(i) CV2.ImRead(): Load an Image

• Loads the image from the path specified.
• The second parameter specifies the color mode.
  • ImreadModes.Color (default): Loads in color (BGR format).
  • ImreadModes.Grayscale: Directly loads the image as grayscale.

(ii) Cv2.CvtColor(): Color Conversion

• Converts an image from one format to another.
• In our example, we convert the original image (in BGR format) to grayscale.

  Cv2.CvtColor(inputImage, grayImage, ColorConversionCodes.BGR2GRAY);

(iii) CV2.ImShow(): Display an Image

• Creates a window and displays the image.
• Parameters
  • Window Name: Unique name for the display window.
  • Image: The Mat object (photo) to display.

(iv) CV2.WaitKey() and Cv2.DestroyAllWindows()

• Cv2.WaitKey() pauses the execution and keeps the image windows open until a key is pressed.
• Cv2.DestroyAllWindows() closes all image display windows once you're done.

5. Next Steps

Now that you've successfully loaded and processed your first image with OpenCV in .NET, the possibilities are endless! Here are some recommended next steps.

Step 1. Try with Other Image Processing Functions.

Explore methods such as blurring, edge detection, and thresholding. Examples include,

• Cv2.GaussianBlur(): Apply a Gaussian blur to an image.
• Cv2.Canny(): Perform edge detection.

Example of detecting edges in a grayscale image.

Mat edges = new Mat();
// Edge detection with thresholds
Cv2.Canny(grayImage, edges, 100, 200);
Cv2.ImShow("Edge Detection", edges);

Step 2. Handle Videos.

Use VideoCapture from OpenCV to process video files or webcam streams.

Step 3. Explore Image Manipulations.

• Cropping
• Rotating
• Resizing images

Step 4. Utilize Object Detection Filters.

Explore advanced topics such as object detection, face recognition, or feature extraction.

Conclusion

Congratulations! You’ve taken your first steps in using OpenCV with .NET through OpenCvSharp. Loading an image and converting it to grayscale is a foundational exercise, setting the stage for more advanced operations, such as image enhancements, object detection, or deep learning integrations.

By adding OpenCV to your software development toolkit, you unlock a world of possibilities for building applications in image processing, computer vision, and beyond. So, keep experimenting and take your application development to the next level!

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SQL Server Integration in Aspire Applications: .NET Aspire Integrations

Databases, caches, message brokers, APIs, telemetry systems, and other supporting technologies are all essential to modern cloud-native applications. Writing business logic is only one aspect of creating such an application; another is carefully connecting these services in a scalable, observable, and maintainable manner. By providing a strong application model that makes it simple for developers to create, set up, and maintain service dependencies,.NET Aspire reduces this complexity.

What do Aspire Integrations bring to the Table?

When you add an integration to an Aspire project, you get.

• Typed configuration and DI setup: Auto-wiring of client libraries with configuration via strongly typed options.
• Health checks: Automatic inclusion of health checks for critical dependencies.
• Connection string propagation: Seamless sharing of connection strings across projects using Aspire's service discovery.
• Dashboard visibility: Integrated resources are visible and traceable through the Aspire Dashboard.
• Simplified Dev Experience: You don’t have to manually set up service bindings or write boilerplate configuration.

These integrations promote a cloud-native design, while also making local development and testing smoother and more predictable.

Common Integrations in .NET Aspire

.NET Aspire comes with official and community-supported packages that make integrating third-party services a breeze. Below is a curated list of popular tools and services across different categories that work seamlessly with Aspire.

Databases

Service	Integration Package	Notes
SQL Server	Aspire.Hosting.SqlServer	Connection string, health check, and discovery are handled automatically.
PostgreSQL	Microsoft.Extensions.Hosting.PostgreSql	Community-supported; connection string injection.
MySQL	Microsoft.Extensions.Hosting.MySql	Similar benefits to PostgreSQL.

Caching & Data Store

Service	Integration Package	Notes
Redis	Microsoft.Extensions.Caching.StackExchangeRedis.Aspire	Adds Redis as a resource, injects connection string, auto configures.
MongoDB	MongoDB.Driver.Aspire (community)	Mongo client setup via Aspire DI.

Messaging & Eventing

Service	Integration Package	Notes
RabbitMQ	Tye.Hosting.RabbitMQ.Aspire (community)	Easy messaging setup.
Azure Service Bus	Microsoft.Azure.ServiceBus.Aspire (planned)	Advanced integration expected in future releases.

Observability & Monitoring

Tool	Integration Package	Notes
OpenTelemetry	Microsoft.Extensions.Telemetry.Aspire	Auto-wires tracing/metrics.
Grafana + Prometheus	Community Templates	Can export Aspire metrics here.

External Services & APIs

Type	Example	Aspire Support Notes
HTTP APIs	REST, GraphQL, gRPC APIs	Use .WithEndpoint() to define upstream APIs.
Cloud SDKs	Azure, AWS	Aspire config + DI bindings are supported manually.

.NET Aspire SQL Server integration

Let’s see in action how to get an Aspire Integrations with SQL Server.

When building distributed applications, a database is often a critical component.

.NET Aspire simplifies integrating SQL Server into your project by providing first-class support through its Aspire.Hosting.SqlServer package.

This integration focuses on,

• Spinning up SQL Server instances (locally or containerized) during development.
• Managing connection strings automatically.
• Sharing database endpoints across your application components.
• Adding health checks for SQL Server availability.
• Visualizing the SQL Server resource in the Aspire Dashboard.

Setting Up SQL Server Integration

Step 1. Install the SQL Server Aspire Package.

In your AppHost project, run.

dotnet add package Aspire.Hosting.SqlServer

Or simply visit to manage NuGet Packages and “Aspire.Hosting.SQLServer” in App Host.

This package brings in the AddSqlServer extension method that makes adding SQL easy.

Step 2. Define the SQL Server Resource.
In your Program.cs inside the AppHost project.

Here is what this code does.

1. Define a parameter for the SQL Server password.

   IResourceBuilder<ParameterResource>? dbPassword =
       builder.AddParameter("dbPassword", true);

Key Points in This Setup

• AddParameter("dbPassword", true): Securely prompts for the database password if it's not already configured.
• AddSqlServer("sql", dbPassword, 1455): Adds a SQL Server resource running on custom port 1455 and uses the provided password.
• .WithLifetime(ContainerLifetime.Persistent): Ensures the SQL Server container persists between runs.
• AddDatabase("database"): Defines a database inside SQL Server for use by the application.
• .WithReference(db) and .WithReference(MyAPI): Links services together by passing resources like connection strings automatically.

Step 3. Configure Parameters Securely.

Instead of hardcoding sensitive information like database passwords in your code, Aspire encourages you to use Parameters.

In your appsettings.json, define the SQL Server password under the Parameters section.

• dbPassword is injected at runtime into the SQL Server resource.
• You can also override it using environment variables or secret managers for production.
• This keeps your applications secure, configurable, and environment-agnostic.

Important. If the “dbPassword” is not found in your settings or environment, Aspire will prompt you to enter it at startup (because of the true flag in AddParameter("dbPassword", true)).

Pro Tip. Managing Sensitive Parameters in .NET Aspire Applications.

• Never hardcode secrets like passwords directly in code files.
• Prefer appsettings.json for local development, but move to secret managers like Azure Key Vault or environment variables in production.
• Use AddParameter with isSecret: true to ensure Aspire handles the value securely, and prompts when missing.
• Do not commit real secrets into your source control repositories (e.g., GitHub).
• Leverage dotnet user-secrets for development.

  dotnet user-secrets set "Parameters:dbPassword" "YourSecurePassword"

• Configure deployment environments to provide required parameters securely during CI/CD pipeline runs.

Aspire Dashboard View

When you run the application, the Aspire Dashboard will show your SQL Server alongside your services, making the architecture and dependencies crystal clear.

Example

[SQL Server] <--- connected to ---> [Web API]

Aspire Dashboard View

When you run the application, the Aspire Dashboard will show your SQL Server alongside your services, making the architecture and dependencies crystal clear.

Example

[SQL Server] <--- connected to ---> [Web API]

SQL

Step 1. SQL Server and Database Creation Verification.

• Open your application in the Aspire Dashboard (localhost:17010).
• In the Resources tab, you will see a list of services.
• Notice two services.
  • SQL (SQL Server): Running state with the source pointing to mcr.microsoft.com/mssql/server2022-latest.
  • Database: Running state.
    
    
    
• These were automatically created based on the definitions provided in your Program.cs file.
• The SQL Server service is configured to expose on tcp://localhost:1455, as per the given port number.

Step 2. Verifying API Environment Variables

• In the Aspire Dashboard, under Resources, locate the API service.
• Click the three dots (...) next to the API service.
• Select View details from the dropdown menu.
  
  
  

Step 3. Checking the Database Connection String.

• In the Project: API details view, scroll to the Environment Variables section.
• Look for the environment variable named: ConnectionStrings__database.
• You will find the database connection string, such as Server=127.0.0.1,1455;User ID=sa;Password=Nit1n5QL;
• This confirms that the API service has the database connection string injected correctly through environment variables.
  
  
  

Step 4. Aspire Action Reflected in Docker (Local).

You can see the side effects of Aspire's local work in Docker Desktop.

• Images: An image mcr.microsoft.com/mssql/server:2022-latest is pulled into Docker.
  
• Containers: A container sql-xxx is running, exposing the SQL Server on port 1455.
  
  
  

Result: Aspire used Docker to spin up the local SQL server dynamically for your app.

Area	Action by Aspire	Result Seen Where
Database Server	SQL Server container created on port 1455	Docker Desktop (Containers tab)
Database Resource	Database initialization or setup done	Aspire Dashboard - Resources
API Env Setup	Database connection string injected automatically	Aspire Dashboard - API - Environment Variables
Docker Image	MSSQL Image pulled if not present	Docker Desktop (Images tab)

Debugging the Connection String: Verify reading the environment variables

Let’s try reading the Connection string from the environment variables, As we have added the reference of SQL Server database to the Weather API Project from App host with Aspire Hosting.

To do that I have added a code to read the connection string from application configuration variables with the name “database” in my API Controller’s Get method “GetWeatherForecast”:

Run the solution and open API swagger to hit the API End Point for debugging the code with a breakpoint on the same line.

You can see the connection string is available for the API Project from the application configurations even though we don’t have any local parameter the name of “database”.

Here is the connection string we got.

Server=127.0.0.1,1455;User ID=sa;Password=Nit1n5QL;TrustServerCertificate=true;Initial Catalog=database

Testing in SSMS

If you want you can use the same connection string in the SQL Server Management Studio to check this Database and its table, which may help you inthe future.

Paste the same connection String in the last tab “Additional Connection Parameters” and hit connect.

I am sure you must be able to see the connected Server and Database in SSMS’s Object Explorer.

Why Use SQL Server Integration with Aspire?

Benefit	Description
Fast Setup	No manual container configuration is needed.
Secure Connection Management	Credentials and connection strings are injected safely.
Automatic Health Monitoring	Built-in health checks for SQL Server connectivity.
Easy Switching	Easily swap local dev SQL Server with Azure SQL for production.

Similarly, you can use Aspire Immigrations for Databases and other tools.

Windows Hosting Recommendation

HostForLIFEASP.NET receives Spotlight standing advantage award for providing recommended, cheap and fast ecommerce Hosting including the latest Magento. From the leading technology company, Microsoft. All the servers are equipped with the newest Windows Server 2022 R2, SQL Server 2022, ASP.NET Core 7.0.10 , ASP.NET MVC, Silverlight 5, WebMatrix and Visual Studio Lightswitch. Security and performance are at the core of their Magento hosting operations to confirm every website and/or application hosted on their servers is highly secured and performs at optimum level. mutually of the European ASP.NET hosting suppliers, HostForLIFE guarantees 99.9% uptime and fast loading speed. From €3.49/month , HostForLIFE provides you with unlimited disk space, unlimited domains, unlimited bandwidth,etc, for your website hosting needs.

 

Read More