C# .NET API Documentation

Core .NET Libraries

The foundational libraries that power all .NET applications.

System namespace: Contains fundamental classes for representing data types, handling exceptions, and performing basic operations.

// Example: Working with strings string message = "Hello, .NET!"; Console.WriteLine(message.ToUpper());

System.Collections namespace: Provides interfaces and classes for common collection types like lists, dictionaries, and queues.

// Example: Using a List List<string> names = new List<string> { "Alice", "Bob", "Charlie" }; names.Add("David"); foreach (var name in names) { Console.WriteLine(name); }

System.IO namespace: Enables reading from and writing to various data sources, including files, streams, and console.

// Example: Reading from a file using (StreamReader reader = new StreamReader("myFile.txt")) { string line; while ((line = reader.ReadLine()) != null) { Console.WriteLine(line); } }

Web Development (ASP.NET Core)

Build modern, cloud-ready, internet-connected applications with ASP.NET Core.

Microsoft.AspNetCore.Mvc: Classes for building Model-View-Controller (MVC) web applications.

ControllerBase.Ok(Object result): Returns an OK response (200) with a JSON serialized body.

Microsoft.AspNetCore.Http: Classes for handling HTTP requests and responses.

// Example: Accessing request headers var userAgent = HttpContext.Request.Headers["User-Agent"]; Console.WriteLine($"User Agent: {userAgent}");

Data Access (Entity Framework Core)

A modern object-relational mapper (ORM) for .NET.

Microsoft.EntityFrameworkCore: Core classes for defining entities and DbContext.

// Example: Querying data using (var context = new MyDbContext()) { var products = await context.Products.Where(p => p.Price > 100).ToListAsync(); foreach (var product in products) { Console.WriteLine($"{product.Name}: {product.Price}"); } }

Windows Desktop Development

Create rich desktop experiences on Windows.

System.Windows.Controls (WPF): UI elements for WPF applications.

// Example: Creating a Button in WPF (XAML) // <Button Content="Click Me" Click="Button_Click" />

System.Windows.Forms (WinForms): Classes for building Windows Forms applications.

// Example: Handling a button click in WinForms // private void button1_Click(object sender, EventArgs e) { // MessageBox.Show("Button clicked!"); // }

Cloud & Azure Integration

Leverage .NET to build and deploy applications on cloud platforms, especially Azure.

Microsoft.Azure.Storage.Blob: APIs for interacting with Azure Blob Storage.

// Example: Uploading a blob // var blobClient = storageAccount.CreateCloudBlobClient(); // var container = blobClient.GetContainerReference("mycontainer"); // var blockBlob = container.GetBlockBlobReference("myblob.txt"); // await blockBlob.UploadTextAsync("This is the blob content.");

Machine Learning with ML.NET

A cross-platform, open-source machine learning framework for .NET developers.

Microsoft.ML: Core classes for building ML models.

// Example: Training a sentiment analysis model // var mlContext = new MLContext(); // var dataView = mlContext.Data.LoadFromTextFile<SentimentData>(dataPath, hasHeader: true); // var pipeline = mlContext.Transforms.Text.FeaturizeText("Features", "Text") // .Append(mlContext.Transforms.Concatenate("Features", "Features")) // .Append(mlContext.BinaryClassification.Trainers.SdcaLogisticRegression(labelColumnName: "Label", featureColumnName: "Features")); // var model = pipeline.Fit(dataView);

Networking APIs

Classes for network communication.

System.Net.Http: For making HTTP requests.

System.Net.Sockets: For low-level network socket programming.

Security

APIs for cryptography, authentication, and authorization.

System.Security.Cryptography: Hashing, encryption, digital signatures.

System.Security.Claims: Working with identity and claims.

Performance & Diagnostics

Tools and APIs for profiling and optimizing applications.

System.Diagnostics: Tracing, performance counters, process management.

Serialization

Converting objects to and from various formats like JSON, XML.

System.Text.Json: High-performance JSON serializer/deserializer.

System.Xml.Serialization: XML serialization.