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Reflection in .NET

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9 Feb 2010CPOL12 min read 481.7K   5.3K   289   60
.NET Framework’s Reflection API allows you to fetch type (assembly) information at runtime.

Contents

Introduction

In this article, I have tried to cover all the topics from .NET Reflection with examples. I have stated with the definition of .NET Reflection and its road map, a list of mostly used classes the System.Reflection namespace provides, and the importance of the Type class in .NET Reflection. You will also learn how to get the type information using different ways. Use of properties and methods of the Type class in .NET Reflection, with examples, are explained in this article. You will also see advanced Reflection topics like dynamically loading an assembly and late binding, at the end of this article.

What is .NET Reflection?

.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. At runtime, the Reflection mechanism uses the PE file to read information about the assembly. Reflection enables you to use code that is not available at compile time. .NET Reflection allows an application to collect information about itself and also to manipulate on itself. It can be used effectively to find all types in an assembly and/or dynamically invoke methods in an assembly. This includes information about the type, properties, methods, and events of an object. With Reflection, we can dynamically create an instance of a type, bind the type to an existing object, or get the type from an existing object and invoke its methods or access its fields and properties. We can also access attribute information using Reflection.

Using Reflection, you can get any kind of information which you can see in a class viewer; for example, information on the methods, properties, fields, and events of an object.

Image 1

The System.Reflection namespace and the System.Type class plays a very important role in .NET Reflection. These two work together and allow you to reflect over many other aspects of a type.

Road Map

The System.Reflection Namespace

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:

ClassDescription
AssemblyRepresents 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.
ModulePerforms Reflection on a module. This class allows you to access a given module within a multi-file assembly.
AssemblyNameThis 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
EventInfoThis class holds information for a given event. Use the EventInfo class to inspect events and to bind to event handlers.
FieldInfoThis 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.
MemberInfoThe 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).
MethodInfoThis class contains information for a given method.
ParameterInfoThis class holds information for a given parameter.
PropertyInfoThis class holds information for a given property.

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

In order to continue with all the examples given in this article, I am using a Car class as an example. It will look like this:

C#
// ICar.cs - Interface 
using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Text; 

namespace Reflection 
{ 
    interface ICar 
    { 
        bool IsMoving(); 
    } 
}

// Car.cs - Class 
using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Text; 

namespace Reflection 
{ 
    internal class Car 
    { 
        //public variables 
        public string Color; 

        //private variables 
        //String licensePlate; // e.g. "Californi 111 222" 
        //double maxSpeed;     // in kilometers per hour 
        //int startMiles; // Stating odometer reading 
        //int endMiles; // Ending odometer reading 
        //double gallons; // Gallons of gas used between the readings  

        //private vaiables 
        private int _speed; 

        //Speed - read-only property to return the speed 
        public int Speed 
        { 
            get { return _speed; } 
        } 

        //Accelerate - add mph to the speed 
        public void Accelerate(int accelerateBy) 
        { 
            //Adjust the speed 
            _speed += accelerateBy; 
        } 

        //IsMoving - is the car moving? 
        public bool IsMoving() 
        { 
            //Is the car's speed zero? 
            if (Speed == 0) 
            { 
                return false; 
            } 
            else 
            { 
                return true; 
            } 
        } 

        //Constructor 
        public Car() 
        { 
            //Set the default values 
            Color = "White"; 
            _speed = 0; 
        } 

        //Over loaded constructor 
        public Car(string color, int speed) 
        { 
            Color = color; 
            _speed = speed; 
        } 

        //methods 
        public double calculateMPG(int startMiles, int endMiles, double gallons) 
        { 
            return (endMiles - startMiles) / gallons; 
        }  
    }
}

// SportsCar.cs - Class 
using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Text; 

namespace Reflection 
{ 
    internal class SportsCar : Car 
    { 
        //Constructor 
        public SportsCar() 
        { 
            //Change the default values 
            Color = "Green"; 
        } 
    }
}

The System.Type Class

The System.Type class is the main class for the .NET Reflection functionality and is the primary way to access metadata. The System.Type class is an abstract class and represents a type in the Common Type System (CLS).

It represents type declarations: class types, interface types, array types, value types, enumeration types, type parameters, generic type definitions, and open or closed constructed generic types.

Use the members of Type to get information about a type declaration, such as the constructors, methods, fields, properties, and events of a class, as well as the module and the assembly in which the class is deployed.

There are tree ways to obtain a Type reference:

Image 2

Using System.Object.GetType()

This method returns a Type object that represents the type of an instance. Obviously, this approach will only work if you have compile-time knowledge of the type.

C#
// ObjectGetTypeDemo.cs 
using System; 
namespace Reflection 
{ 
    class ObjectGetTypeDemo 
    { 
        static void Main(string[] args) 
        { 
            Car c = new Car(); 
            Type t = c.GetType(); 
            Console.WriteLine(t.FullName); 
            Console.ReadLine(); 
        } 
    } 
}

Output

Reflection.Car

Using System.Type.GetType()

Another way of getting type information in a more flexible manner is the GetType() static method of the Type class which gets the type with the specified name, performing a case-sensitive search.

Type.GetType() is an overloaded method that accepts the following parameters:

  1. fully qualified string name of the type you are interested in examining
  2. exception that should be thrown if the type cannot be found
  3. establishes the case sensitivity of the string
C#
// TypeGetTypeDemo.cs 
using System; 
namespace Reflection 
{ 
    class TypeGetTypeDemo 
    { 
        static void Main(string[] args) 
        { 
            // Obtain type information using the static Type.GetType() method. 
            // (don't throw an exception if Car cannot be found and ignore case). 
            Type t = Type.GetType("Reflection.Car", false, true); 

            Console.WriteLine(t.FullName); 
            Console.ReadLine(); 
        } 
    } 
}

Output

Reflection.Car

Using the typeof () C# Operator

The final way to obtain type information is using the C# typeof operator. This operator takes the name of the type as a parameter.

C#
// TypeofDemo.cs 
using System; 
namespace Reflection 
{ 
    class TypeofDemo 
    { 
        static void Main(string[] args) 
        { 
            // Get the Type using typeof. 
            Type t = typeof(Car); 
            Console.WriteLine(t.FullName); 
            Console.ReadLine(); 
        } 
    } 
}

Output

Reflection.Car

Type Properties

The System.Type class defines a number of members that can be used to examine a type's metadata, a great number of which return types from the System.Reflection namespace.

You can split the properties implemented by Type into three categories:

  1. A number of properties retrieve the strings containing various names associated with the class, as shown in the following table:
  2. PropertyReturns
    NameThe name of the data type.
    FullNameThe fully qualified name of the data type (including the namespace name).
    NamespaceThe name of the namespace in which the data type is defined.
  3. It is also possible to retrieve references to further type objects that represent related classes, as shown in the following table:
  4. PropertyReturns Type Reference Corresponding To
    BaseTypeImmediate base type of this type.
    UnderlyingSystemTypeThe type that this type maps to in the .NET runtime (recall that certain .NET base types actually map to specific predefined types recognized by IL).
  5. A number of Boolean properties indicating whether this type is, for example, a class, an enum, and so on.
  6. TypeMeaning in Life
    • IsAbstract
    • IsArray
    • IsClass
    • IsCOMObject
    • IsEnum
    • IsGenericTypeDefinition
    • IsGenericParameter
    • IsInterface
    • IsPrimitive
    • IsPublic
    • IsNestedPrivate
    • IsNestedPublic
    • IsSealed
    • IsValueType
    • IsPointer
    These properties (among others) allow you to discover a number of basic traits about the type you are referring to.

Here is the example of displaying type information using the System.Type class properties:

C#
// TypePropertiesDemo.cs 
using System; 
using System.Text; 
using System.Reflection; 

namespace Reflection 
{ 
    class TypePropertiesDemo 
    { 
        static void Main() 
        { 
            // modify this line to retrieve details of any other data type 
            // Get name of type 
            Type t = typeof(Car); 
            GetTypeProperties(t); 
            Console.ReadLine(); 
        } 
        public static void GetTypeProperties(Type t) 
        { 
            StringBuilder OutputText = new StringBuilder(); 

            //properties retrieve the strings 
            OutputText.AppendLine("Analysis of type " + t.Name); 
            OutputText.AppendLine("Type Name: " + t.Name); 
            OutputText.AppendLine("Full Name: " + t.FullName); 
            OutputText.AppendLine("Namespace: " + t.Namespace); 

            //properties retrieve references        
            Type tBase = t.BaseType; 

            if (tBase != null) 
            { 
                OutputText.AppendLine("Base Type: " + tBase.Name); 
            } 

            Type tUnderlyingSystem = t.UnderlyingSystemType; 

            if (tUnderlyingSystem != null) 
            { 
                OutputText.AppendLine("UnderlyingSystem Type: " +
                    tUnderlyingSystem.Name); 
                //OutputText.AppendLine("UnderlyingSystem Type Assembly: " +
                //    tUnderlyingSystem.Assembly); 
            } 

            //properties retrieve boolean         
            OutputText.AppendLine("Is Abstract Class: " + t.IsAbstract); 
            OutputText.AppendLine("Is an Arry: " + t.IsArray); 
            OutputText.AppendLine("Is a Class: " + t.IsClass); 
            OutputText.AppendLine("Is a COM Object : " + t.IsCOMObject); 

            OutputText.AppendLine("\nPUBLIC MEMBERS:"); 
            MemberInfo[] Members = t.GetMembers(); 

            foreach (MemberInfo NextMember in Members) 
            { 
                OutputText.AppendLine(NextMember.DeclaringType + " " + 
                NextMember.MemberType + "  " + NextMember.Name); 
            } 
            Console.WriteLine(OutputText); 
        } 
    } 
}

Output

Analysis of type Car 
Type Name: Car 
Full Name: Reflection.Car 
Namespace: Reflection 
Base Type: Object 
UnderlyingSystem Type: Car 
Is Abstract Class: False 
Is an Arry: False 
Is a Class: True 
Is a COM Object : False

Public members

Reflection.Car Method  get_Speed 
Reflection.Car Method  Accelerate 
Reflection.Car Method  IsMoving 
Reflection.Car Method  calculateMPG 
System.Object Method  ToString 
System.Object Method  Equals 
System.Object Method  GetHashCode 
System.Object Method  GetType 
Reflection.Car Constructor  .ctor 
Reflection.Car Constructor  .ctor 
Reflection.Car Property  Speed 
Reflection.Car Field  Color

Type Methods

Most of the methods of System.Type are used to obtain details of the members of the corresponding data type - the constructors, properties, methods, events, and so on. Quite a large number of methods exist, but they all follow the same pattern.

Returned TypeMethods (the method with the plural name returns an Array)Description
ConstructorInfoGetConstructor(), GetConstructors()These methods allow you to obtain an array representing the items (interface, method, property, etc.) you are interested in. Each method returns a related array (e.g., GetFields() returns a FieldInfo array, GetMethods() returns a MethodInfo array, etc.). Be aware that each of these methods has a singular form (e.g., GetMethod(), GetProperty(), etc.) that allows you to retrieve a specific item by name, rather than an array of all related items.
EventInfoGetEvent(), GetEvents()
FieldInfoGetField(), GetFields()
InterfaceInfoGetInterface(), GetInterfaces()
MemberInfoGetMember(), GetMembers()
MethodInfoGetMethod(), GetMethods()
PropertyInfoGetProperty(), GetProperties()
 FindMembers()This method returns an array of MemberInfo types based on a search criteria.
TypeGetType()This static method returns a Type instance given a string name.
 InvokeMember()This method allows late binding to a given item.

For example, two methods retrieve details of the methods of the data type: GetMethod() and GetMethods().

C#
Type t = typeof(Car); 
MethodInfo[] methods = t.GetMethods(); 
foreach (MethodInfo nextMethod in methods) 
{ 
                // etc. 
}

Reflecting on Methods

GetMethod() returns a reference to a System.Reflection.MethodInfo object, which contains details of a method. Searches for the public method with the specified name.

GetMethods() returns an array of such references. The difference is that GetMethods() returns details of all the methods, whereas GetMethod() returns details of just one method with a specified parameter list.

Both methods have overloads that take an extra parameter, a BindingFlags enumerated value that indicates which members should be returned - for example, whether to return public members, instance members, static members, and so on.

MethodInfo is derived from the abstract class MethodBase, which inherits MemberInfo. Thus, the properties and methods defined by all three of these classes are available for your use.

Image 3

For example, the simplest overload of GetMethods() takes no parameters:

C#
// GetMethodsDemo.cs 
using System; 
using System.Reflection; 

namespace Reflection 
{ 
    class GetMethodsDemo 
    { 
        static void Main() 
        { 
            // Get name of type 
            Type t = typeof(Car); 
            GetMethod(t); 
            GetMethods(t); 

            Console.ReadLine(); 
        } 

        // Display method names of type. 
        public static void GetMethods(Type t) 
        { 
            Console.WriteLine("***** Methods *****"); 
            MethodInfo[] mi = t.GetMethods(); 
            foreach (MethodInfo m in mi) 
                Console.WriteLine("->{0}", m.Name); 
            Console.WriteLine(""); 
        } 

        // Display method name of type. 
        public static void GetMethod(Type t) 
        { 
            Console.WriteLine("***** Method *****"); 
            //This searches for name is case-sensitive. 
            //The search includes public static and public instance methods. 
            MethodInfo mi = t.GetMethod("IsMoving"); 
            Console.WriteLine("->{0}", mi.Name); 
            Console.WriteLine(""); 
        } 
    } 
}

Output

***** Method ***** 
->IsMoving 
***** Methods ***** 

->get_Speed 
->Accelerate 
->IsMoving 
->calculateMPG 
->ToString 
->Equals 
->GetHashCode 
->GetType

Here, you are simply printing the name of the method using the MethodInfo.Name property. As you might guess, MethodInfo has many additional members that allow you to determine if the method is static, virtual, or abstract. Also, the MethodInfo type allows you to obtain the method's return value and parameter set.

A Second Form of GetMethods( )

A second form of GetMethods( ) lets you specify various flags that filter the methods that are retrieved. It has this general form:

C#
MethodInfo[ ] GetMethods(BindingFlags flags)

This version obtains only those methods that match the criteria that you specify. BindingFlags is an enumeration. Here are several commonly used values:

ValueMeaning
DeclaredOnlyRetrieves only those methods defined by the specified class. Inherited methods are not included.
InstanceRetrieves instance methods.
NonPublicRetrieves non-public methods.
PublicRetrieves public methods.
StaticRetrieves static methods.

You can OR together two or more flags. In fact, minimally, you must include either Instance or Static with Public or NonPublic. Failure to do so will result in no methods being retrieved.

One of the main uses of the BindingFlags form of GetMethods( ) is to enable you to obtain a list of the methods defined by a class without also retrieving the inherited methods. This is especially useful for preventing the methods defined by an object from being obtained. For example, try substituting this call to GetMethods( ) into the preceding program:

C#
// Now, only methods declared by MyClass are obtained. 

MethodInfo[] mi = t.GetMethods(BindingFlags.DeclaredOnly | 
                               BindingFlags.Instance |
                               BindingFlags.Public);

Reflecting on Fields and Properties

The behavior of Type.GetField() and Type.GetFields() is exactly similar to the above two methods, except Type.GetField() returns a reference of System.Reflection.MethodInfo and Type.GetFields() returns a reference of a System.Reflection.MethodInfo array. Similarly, Type.GetProperty() and Type.GetProperties() too.

The logic to display a type's properties is similar:

C#
// GetFieldsPropertiesDemo.cs 
using System; 
using System.Reflection; 

namespace Reflection 
{ 
    class GetFieldsPropertiesDemo 
    { 
        static void Main() 
        { 
            // Get name of type 
            Type t = typeof(Car); 
            GetFields(t); 
            GetProperties(t); 

            Console.ReadLine(); 
        } 

        // Display field names of type. 
        public static void GetFields(Type t) 
        { 
            Console.WriteLine("***** Fields *****"); 
            FieldInfo[] fi = t.GetFields(); 
            foreach (FieldInfo field in fi) 
                Console.WriteLine("->{0}", field.Name); 
            Console.WriteLine(""); 
        } 

        // Display property names of type. 
        public static void GetProperties(Type t) 
        { 
            Console.WriteLine("***** Properties *****"); 
            PropertyInfo[] pi = t.GetProperties(); 
            foreach (PropertyInfo prop in pi) 
                Console.WriteLine("->{0}", prop.Name); 
            Console.WriteLine(""); 
        } 
    }
}

Output

***** Fields ***** 
->Color 
***** Properties ***** 
->Speed

Reflecting on Implemented Interfaces

GetInterfaces() returns an array of System.Types! This should make sense given that interfaces are, indeed, types:

C#
// GetInterfacesDemo.cs 
using System; 
using System.Reflection; 

namespace Reflection 
{ 
    class GetInterfacesDemo 
    { 
        static void Main() 
        { 
            // Get name of type 
            Type t = typeof(Car); 
            GetInterfaces(t); 

            Console.ReadLine(); 
        } 

        // Display implemented interfaces. 
        public static void GetInterfaces(Type t) 
        { 
            Console.WriteLine("***** Interfaces *****"); 
            Type[] ifaces = t.GetInterfaces(); 
            foreach (Type i in ifaces) 
                Console.WriteLine("->{0}", i.Name); 
        } 
    } 
}

Output

***** Interfaces ***** 
->ICar

Reflecting on Method Parameters and Return Values

To play with method parameters and return types, we first need to build a MethodInfo[] array using the GetMethods() function.

The MethodInfo type provides the ReturnType property and the GetParameters() method for these very tasks.

C#
using System; 
using System.Reflection; 
using System.Text; 

namespace Reflection 
{ 
    class GetParameterInfoDemo 
    { 
        static void Main() 
        { 
            // Get name of type 
            Type t = typeof(Car); 
            GetParametersInfo(t); 

            Console.ReadLine(); 
        } 

        //Display Method return Type and paralmeters list 
        public static void GetParametersInfo(Type t) 
        { 
            Console.WriteLine("***** GetParametersInfo *****"); 
            MethodInfo[] mi = t.GetMethods(); 
            foreach (MethodInfo m in mi) 
            { 
                // Get return value. 
                string retVal = m.ReturnType.FullName; 
                StringBuilder paramInfo = new StringBuilder(); 
                paramInfo.Append("("); 

                // Get params. 
                foreach (ParameterInfo pi in m.GetParameters()) 
                { 
                    paramInfo.Append(string.Format("{0} {1} ", pi.ParameterType,
                        pi.Name)); 
                } 
                paramInfo.Append(")"); 

                // Now display the basic method sig. 
                Console.WriteLine("->{0} {1} {2}", retVal, m.Name, paramInfo); 
            } 
            Console.WriteLine(""); 
        } 
    } 
}

Output

***** GetParametersInfo ***** 
->System.Int32 get_Speed () 
->System.Void Accelerate (System.Int32 accelerateBy ) 
->System.Boolean IsMoving () 
->System.Double calculateMPG (System.Int32 startMiles System.Int32 endMiles Syst 
em.Double gallons ) 
->System.String ToString () 
->System.Boolean Equals (System.Object obj ) 
->System.Int32 GetHashCode () 
->System.Type GetType ()

Reflecting on Constructor

The GetConstractors() function returns an array of ConstractorInfo elements which we can use to get more class constructor information.

C#
// GetConstractorInfoDemo.cs 
using System; 
using System.Reflection; 

namespace Reflection 
{ 
    class GetConstractorInfoDemo 
    { 
        static void Main() 
        { 
            // Get name of type 
            Type t = typeof(Car); 
            GetConstructorsInfo(t); 

            Console.ReadLine(); 
        } 

        // Display method names of type. 
        public static void GetConstructorsInfo(Type t) 
        { 
            Console.WriteLine("***** ConstructorsInfo *****"); 
            ConstructorInfo[] ci = t.GetConstructors (); 
            foreach (ConstructorInfo  c in ci) 
                Console.WriteLine(c.ToString () ); 
            Console.WriteLine(""); 
        } 
    } 
}

Output

***** ConstructorsInfo ***** 
Void .ctor() 
Void .ctor(System.String, Int32)

Assembly Class

The System.Reflection namespace provides a class called Assembly. We can use this Assembly class to fetch information about the assembly and manipulate the provided assembly; this class allows us to load modules and assemblies at run time. The Assembly class contacts the PE file to fetch the metadata information about the assembly at runtime. Once we load the assembly using this Assembly class, we can search the type information within the assembly. It is also possible to create instances of types returned by the Assembly class.

Dynamically Loading an Assembly

The Assembly class provides the following methods to load an assembly at runtime:

  • Load(): This static overloaded method takes the assembly name as input parameter and searches the given assembly name in the system.
  • LoadFrom(): This static overloaded method takes the complete path of an assembly, it will directly look into that particular location instead of searching in the system.
  • GetExecutingAssembly(): The Assembly class also provides another method to obtain the currently running assembly information using the GetExecutingAssembly() methods. This method is not overloaded.
  • GetTypes(): The Assembly class also provides a nice feature called the GetTypes method which allows you to obtain the details of all the types that are defined in the corresponding assembly.
  • GetCustomAttributes(): This static overloaded method gets the attributes attached to the assembly. You can also call GetCustomAttributes(), specifying a second parameter, which is a Type object that indicates the attribute class in which you are interested.
C#
// AssemblyDemo.cs 
class AssemblyDemo 
{ 
    static void Main() 
    { 
        Assembly objAssembly; 

        // You must supply a valid fully qualified assembly name here.
        objAssembly = Assembly.Load("mscorlib,2.0.0.0,Neutral,b77a5c561934e089"); 

        // Loads an assembly using its file name   
        //objAssembly = Assembly.LoadFrom(
        //    @"C:\Windows\Microsoft.NET\Framework\v1.1.4322\caspol.exe"); 

        //this loads currnly running process assembly 
        // objAssembly = Assembly.GetExecutingAssembly(); 

        Type[] Types = objAssembly.GetTypes(); 

        // Display all the types contained in the specified assembly. 
        foreach (Type objType in Types) 
        { 
            Console.WriteLine(objType.Name.ToString()); 
        } 

        //fetching custom attributes within an assembly 
        Attribute[] arrayAttributes = 
        Attribute.GetCustomAttributes(objAssembly); 

        // assembly1 is an Assembly object 
        foreach (Attribute attrib in arrayAttributes) 
        { 
            Console.WriteLine(attrib.TypeId ); 
        } 

        Console.ReadLine(); 
    }
}

Image 4

Late Binding

Late binding is a powerful technology in .NET Reflection which allows you to create an instance of a given type and invoke its members at runtime without having compile-time knowledge of its existence; this technique is also called dynamic invocation. This technique is useful only when working with an object which is not available at compile time. In this technique, it is the developer's responsibility to pass the correct signature of the methods before invoking; otherwise, it will throw an error, whereas in early binding, the compiler verifies the method signature before calling the method. It is very important to take the right decision when to call and use and when not to use this because of performance issues. Using this technique has an impact on the performance of your application.

C#
// LateBindingDemo.cs 
using System; 
using System.Reflection; 

namespace Reflection 
{ 
    class LateBindingDemo 
    { 
        static void Main() 
        { 
            Assembly objAssembly; 
            // Loads an assembly  
            objAssembly = Assembly.GetExecutingAssembly(); 

            //get the class type information in which late bindig applied 
            Type classType = objAssembly.GetType("Reflection.Car");

            //create the instance of class using System.Activator class 
            object  obj  =  Activator.CreateInstance(classType); 

            //get the method information 
            MethodInfo mi = classType.GetMethod("IsMoving"); 

            //Late Binding using Invoke method without parameters 
            bool isCarMoving; 
            isCarMoving= (bool) mi.Invoke(obj, null); 
            if (isCarMoving) 
            { 
                Console.WriteLine("Car Moving Status is : Moving"); 
            } 
            else 
            { 
                Console.WriteLine("Car Moving Status is : Not Moving"); 
            } 

            //Late Binding with parameters 
            object[] parameters = new object[3]; 
            parameters[0] = 32456;//parameter 1 startMiles 
            parameters[1] = 32810;//parameter 2 end Miles 
            parameters[2] = 10.6;//parameter 3 gallons 
            mi = classType.GetMethod("calculateMPG"); 
            double MilesPerGallon; 
            MilesPerGallon= (double ) mi.Invoke(obj, parameters); 
            Console.WriteLine("Miles per gallon is : " + MilesPerGallon); 

            Console.ReadLine(); 
        } 
    } 
}

Output

Car Moving Status is : Not Moving 
Miles per gallon is : 33.3962264150943

Reflection Emit

Reflection emit supports dynamic creation of new types at runtime. You can define an assembly to run dynamically or to save itself to disk, and you can define modules and new types with methods that you can then invoke.

Conclusion

Reflection in .NET is huge. Covering an entire API is not possible in this article. However, learning one part of it will give you a complete understanding of Reflection in .NET.

Thanks for reading my article. I hope you enjoyed it very much.

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)



Comments and Discussions

 
GeneralMy vote of 5 Pin
W Balboos, GHB16-Sep-16 6:55
W Balboos, GHB16-Sep-16 6:55 
PraiseWonderful article, very good! Make Reflection much easier to be understood. Pin
xuanguang13-Sep-16 20:44
xuanguang13-Sep-16 20:44 
GeneralGreat Article Pin
AndaROM26-Jun-15 9:40
AndaROM26-Jun-15 9:40 
QuestionGreat article Pin
GuyThiebaut13-May-15 0:53
professionalGuyThiebaut13-May-15 0:53 
GeneralMy vote of 5 Pin
khurram ali lashari24-Jan-15 17:41
professionalkhurram ali lashari24-Jan-15 17:41 
GeneralMy vote of 4 Pin
Ashish Rathod-.Net Developer4-Aug-14 4:10
professionalAshish Rathod-.Net Developer4-Aug-14 4:10 
Generalsay tks you very much Pin
thangpdtt5-May-14 20:02
thangpdtt5-May-14 20:02 
GeneralMy vote of 5 Pin
thangpdtt5-May-14 19:59
thangpdtt5-May-14 19:59 
QuestionBest One Pin
Member 101992864-Feb-14 2:05
professionalMember 101992864-Feb-14 2:05 
QuestionInvoking method from dll using Reflection Pin
Prabhu S M9-Jan-14 23:31
Prabhu S M9-Jan-14 23:31 
Questionabout Type.GetMethod(string methodName, Type[] types) Pin
Dude76Fr29-Nov-13 2:25
Dude76Fr29-Nov-13 2:25 
GeneralMy vote of 5 Pin
ashok rathod3-Jul-13 17:52
professionalashok rathod3-Jul-13 17:52 
GeneralExcellent article Pin
Ivan Podvezanec14-Jun-13 2:08
Ivan Podvezanec14-Jun-13 2:08 
QuestionReflection Article Pin
ravi kewat3-Jun-13 0:41
ravi kewat3-Jun-13 0:41 
GeneralMy vote of 5 Pin
Manuj Chugh12-May-13 20:35
Manuj Chugh12-May-13 20:35 
GeneralMy vote of 4 Pin
Nani Babu2-May-13 4:29
Nani Babu2-May-13 4:29 
GeneralMy vote of 5 Pin
Bejay Waddell2-May-13 1:06
Bejay Waddell2-May-13 1:06 
GeneralMy vote of 5 Pin
Cindy Meister30-Apr-13 10:45
Cindy Meister30-Apr-13 10:45 
GeneralMy vote of 5 Pin
angshumandash1-Mar-13 18:14
angshumandash1-Mar-13 18:14 
QuestionGood Article Pin
angshumandash1-Mar-13 18:13
angshumandash1-Mar-13 18:13 
Questionrelated to reflection Pin
Member 97888271-Mar-13 17:06
Member 97888271-Mar-13 17:06 
QuestionCorrection? Pin
yudhoahmad12-Oct-12 13:34
yudhoahmad12-Oct-12 13:34 
Best Article!
Just under "Reflecting on Fields and Properties" section, there is a paragraph stating that GetField() returns MethodInfo type of object and GetFields() returns array of MethodInfo objects.
I think it should be FieldInfo and array of FieldInfo objects respectively?
Am I right, or wrong?
GeneralMy vote of 5 Pin
Member 935574013-Aug-12 18:46
Member 935574013-Aug-12 18:46 
GeneralMy vote of 4 Pin
OChristiaanse25-Jun-12 4:25
OChristiaanse25-Jun-12 4:25 
QuestionAre u sure thats correct? Pin
FrazMann24-Jun-12 9:52
FrazMann24-Jun-12 9:52 

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