.NET Base Class Library (BCL)
The .NET Base Class Library (BCL) is a collection of fundamental types and classes that are available to all .NET developers. It provides a rich set of pre-built functionalities for common programming tasks, enabling rapid application development.
The BCL is organized into namespaces, which group related types and functionalities. Understanding the BCL is crucial for effectively leveraging the power of the .NET platform.
Key Features of the BCL
- Collections: Provides generic and non-generic collection types for managing data structures like lists, dictionaries, queues, and stacks.
- Input/Output (I/O): Offers classes for working with files, streams, directories, and network connections.
- String Manipulation: Includes powerful classes for manipulating strings, such as
string,StringBuilder, and formatting options. - Networking: Provides types for building network applications, including HTTP clients, sockets, and IP addresses.
- Threading: Supports multithreaded programming with classes for creating, managing, and synchronizing threads.
- Serialization: Enables the conversion of objects into a format that can be stored or transmitted, and vice versa.
- Reflection: Allows you to inspect and manipulate metadata of types and assemblies at runtime.
Commonly Used Namespaces
Some of the most frequently used BCL namespaces include:
System: The root namespace for fundamental types, including basic data types, exceptions, and core runtime services.System.Collections: Contains interfaces and classes that define various collections of objects.System.Collections.Generic: Provides generic collection types that offer type safety and better performance.System.IO: Contains types for reading and writing files and data streams.System.Text: Includes classes for manipulating strings and encoding/decoding text.System.Net: Provides classes for network programming.System.Threading: Offers classes for multithreaded programming.
Example: Working with Collections
Here's a simple example demonstrating the use of the List<T> generic collection:
using System;
using System.Collections.Generic;
public class Example
{
public static void Main(string[] args)
{
List<string> fruits = new List<string>();
fruits.Add("Apple");
fruits.Add("Banana");
fruits.Add("Cherry");
Console.WriteLine("Fruits in the list:");
foreach (string fruit in fruits)
{
Console.WriteLine($"- {fruit}");
}
Console.WriteLine($"\nTotal fruits: {fruits.Count}");
}
}Key Classes and Concepts
System.Object
public class Object
The ultimate base class for all types in the .NET Framework, providing default implementations for common operations.
System.String
public sealed class String
Represents a sequence of characters. Strings are immutable in .NET.
Common Methods:
string.Length: Gets the number of characters in the string.
string.Contains(string value): Determines whether the specified string contains a specified character.
string.ToUpper(): Converts the current string to uppercase.
System.Console
public static class Console
Represents the standard input, output, and error streams for console applications.
Common Methods:
Console.WriteLine(string value): Writes the specified string value to the standard output stream.
Console.ReadLine(): Reads the next line of characters from the standard input stream.
System.Exception
public class Exception
The base class for all exceptions in the .NET Framework. Used to signal errors.