Exploring What’s New in .NET 9: A Comprehensive Guide With Example

.NET 9 brings a plethora of enhancements aimed at optimizing performance, bolstering security, and improving developer productivity. In this blog, we’ll dive deep into the most significant features and updates introduced in this latest release. From dynamic performance enhancements to innovative tools for multi-platform development, .NET 9 sets a new benchmark in software development. Let’s explore these updates in detail.

Performance Enhancements

Dynamic Adaptation to Application Sizes (DATAS)

One of the standout features in .NET 9 is the introduction of DATAS, a mechanism for the garbage collector to dynamically adjust to application memory requirements. This feature is particularly beneficial for applications with unpredictable workloads.

• Adaptive Garbage Collection: By dynamically tuning its behavior based on runtime analysis, the garbage collector optimizes memory usage, reduces latency, and prevents unnecessary pauses.
• Impact on Cloud Applications: Applications hosted in environments with fluctuating memory demands, such as cloud-native applications, can benefit significantly from this feature.

Example: Consider an e-commerce platform experiencing spikes in traffic during sales events. The DATAS feature enables the garbage collector to efficiently manage memory, ensuring seamless user experience even under heavy load.

Source Code:

using System;
using System.Diagnostics;
class Program
{
    static void Main()
    {
        Console.WriteLine("Simulating workload...");
        for (int i = 0; i < 10000; i++)
        {
            var temp = new byte[1024 * 1024]; // Allocate memory dynamically
        }
        Console.WriteLine("Workload simulation complete.");
        GC.Collect(); // Trigger garbage collection manually to observe behavior
    }
}

Enhanced Arm64 Support

.NET 9 includes improvements that enhance performance on Arm64 processors, which are becoming increasingly prevalent in cloud, edge, and IoT devices.

• Better Vectorization: Enhanced code generation leads to faster execution of computational tasks.
• Cross-Platform Edge Computing: These updates make .NET a stronger choice for edge computing scenarios, where Arm64 devices are often used.

Example: A machine learning inference application running on an Arm64-based edge device processes image data 20% faster due to improved vectorization in .NET 9.

Source Code:

using System;
using System.Numerics;

class Program
{
    static void Main()
    {
        var vector1 = new Vector<float>(new float[] {1.0f, 2.0f, 3.0f, 4.0f});
        var vector2 = new Vector<float>(new float[] {5.0f, 6.0f, 7.0f, 8.0f});
        var result = Vector.Multiply(vector1, vector2);
        Console.WriteLine("Vector multiplication result: " + result);
    }
}

ASP.NET Core Improvements

Static Asset Handling

Efficient management of static files is crucial for web applications, and .NET 9 introduces the MapStaticAssets feature to streamline this process.

• Automated Compression: Assets are automatically compressed for faster delivery.
• Cache Optimization: Built-in caching ensures that frequently accessed assets load quickly, improving user experience.
• Versioning Support: Simplifies cache invalidation for updated assets.

Example: A single-page application can now use MapStaticAssets to ensure all JavaScript and CSS files are minified and cached, significantly improving load times for end users.

Source Code:

using Microsoft.AspNetCore.Builder;
using Microsoft.Extensions.Hosting;

var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();

app.MapStaticAssets(); // Enable static asset handling
app.Run();

Blazor Enhancements

Blazor, the framework for building interactive web UIs, receives several notable updates:

• Runtime Component State API: Developers can now query and manipulate the state of Blazor components during runtime, enabling more dynamic and interactive user experiences.
• Static Server-Side Rendering Improvements: The [ExcludeFromInteractiveRouting] attribute allows developers to mark specific components for static rendering, enhancing load times for server-side Blazor apps.

Example: A Blazor application uses the Runtime Component State API to track user interactions, such as form completion status, and dynamically adjust the UI to guide users through the process.

Source Code:

@code {
    private bool IsFormComplete { get; set; } = false;
    private void CheckFormCompletion()
      {
          // Simulate form completion logic
          IsFormComplete = true;
      }
}
@if (!IsFormComplete)
{
    <button @onclick="CheckFormCompletion">Complete Form</button>
}
else
{
    <p>Form completed!</p>
}

SignalR Updates

SignalR, the library for real-time communication, is more powerful in .NET 9:

• Polymorphic Hub Method Arguments: Supports passing complex object hierarchies as arguments to hub methods.
• Enhanced Activity Tracking: Improved diagnostics provide insights into connection health and message flows, aiding in debugging and performance tuning.

Example: A chat application leverages polymorphic hub arguments to handle various message types — text, images, and files — with a single SignalR method.

Source Code:

using Microsoft.AspNetCore.SignalR;
public class ChatHub : Hub
{
    public async Task SendMessage(object message)
    {
        await Clients.All.SendAsync("ReceiveMessage", message);
    }
}
// Client-side JS example
// connection.on('ReceiveMessage', message => console.log(message));

.NET MAUI (Multi-platform App UI) Updates

HybridWebView Control

.NET 9 introduces the HybridWebView control, a versatile addition to the MAUI toolkit:

• Web Content Embedding: Developers can seamlessly embed web-based content within native applications.
• Hybrid App Development: This control bridges the gap between native and web app development, making it easier to create hybrid applications.

Example: A financial app uses the HybridWebView to display interactive stock charts from a web-based analytics service, blending native navigation with web content.

Source Code:

using Microsoft.Maui.Controls;
public class MainPage : ContentPage
{
    public MainPage()
    {
        var webView = new HybridWebView
        {
            Source = "https://example.com/charts"
        };
        Content = webView;
    }
}

System.Text.Json Enhancements

JSON Schema Generation

With the new capability to generate JSON schemas from .NET classes, developers can:

• Simplify API Documentation: Automatically produce schemas for RESTful API documentation.
• Ensure Data Validation: Validate incoming JSON payloads against predefined schemas.

Example: A payment gateway API uses JSON schema generation to validate transaction requests, reducing the risk of invalid data causing errors.

Source Code:

using System.Text.Json;
using System.Text.Json.Serialization;

public class PaymentRequest
{
    public string CardNumber { get; set; }
    public decimal Amount { get; set; }
}
var options = new JsonSerializerOptions
{
    WriteIndented = true
};
var schema = JsonSchemaGenerator.GenerateSchema(typeof(PaymentRequest));
Console.WriteLine(schema);

Conclusion

.NET 9 represents a significant step forward, offering tools and features that address modern development challenges. Whether you’re building cloud-native applications, optimizing for edge computing, or developing cross-platform apps, .NET 9 equips you with the capabilities to succeed.

With performance enhancements, security improvements, and developer-centric updates, it’s an exciting time to be a .NET developer. Dive into .NET 9 today and explore how these features can elevate your projects.