What is .NET Reflection? why and when we use it ?

.NET Framework's Reflection API allows you to fetch type (assembly) information at runtime programmatically. We can also achieve late binding by using .NET Reflection.
Assemblies contain modules, modules contain types, and types contain members.

At runtime, the Reflection mechanism uses the PE file to read information about the assembly.


The System.Reflection namespace contains the classes and interfaces that provide a managed view of loaded types, methods, and fields, with the ability to dynamically create and invoke types; this process is known as Reflection in .NET framework. We will take a look at some of the commonly used classed here:

Class	Description
Assembly	Represents an assembly, which is a reusable, versionable, and self-describing building block of a Common Language Runtime application. This class contains a number of methods that allow you to load, investigate, and manipulate an assembly.
Module	Performs Reflection on a module. This class allows you to access a given module within a multi-file assembly.
AssemblyName	This class allows you to discover numerous details behind an assembly's identity. An assembly's identity consists of the following: Simple name Version number Cryptographic key pair Supported culture
EventInfo	This class holds information for a given event. Use the EventInfo class to inspect events and to bind to event handlers.
FieldInfo	This class holds information for a given field. Fields are variables defined in the class. FieldInfo provides access to the metadata for a field within a class, and provides dynamic set and get functionality for the field. The class is not loaded into memory until Invoke or get is called on the object.
MemberInfo	The MemberInfo class is the abstract base class for classes used to obtain information about all members of a class (constructors, events, fields, methods, and properties).
MethodInfo	This class contains information for a given method.
ParameterInfo	This class holds information for a given parameter.
PropertyInfo	This class holds information for a given property.

Before we start using Reflection, it is necessary to understand the System.Type class.