Language Interoperability in .Net
In this article I have explained What is Language Interoperability and How it works in .Net. With the help of Language Interoperability you can interact with all Other Languages of .Net.With Interoperability you can interact with all the Languages in .Net .We can Save the Time instead of Generating the same Code Again and Again
What is .Net ?
1).Net is a Platform Independent Language which is used for developing various applications like Windows Applications,Web Applications ,Mobile Applications .
2).Net is a collection of more than 20 languages.Among them mostly used languages are C#.Net,VB.Net.
Though,.Net is collection of several languages Every language has its own compiler. VB.Net uses VB Compilier and C# uses C# compiler for Compilation.Every .Net Language after Compilation generates CIL Code.
What is CIL ?
CIL is the Common Intermediate Language which is generated after the Compilation of the Code.
After Compiling Vb.net code with its VB Compiler we get CIL Code.
After compiling C# code with its C# Compiler we get CIL Code.
CIL is the Intermediate Code which we get After the Compilation of the Source Code
What is Machine Code ?
Each Machine whether it is Windows or Unix consists of its own Software and Hardware . It consists of its own MicroProcessor. Every Machine will have some Instructions which can be understood by its own MicroProcessor .Those Instructions are nothing but Machine code(Machine Instructions)
What is CLR ?
Machine cannot Understand CIL Code which we get after the Compilation of a Program
CLR is used for converting the CIL Code into Corresponding Machine Code (Machine Instructions) which can be understand by its own MicroProcessor
What is Language Interoperability ?
Code which is written in any .NET Language can be consumed in other .NET Language.This is called as Language Interoperability .
Every .Net Language after Compiling generates CIL Code which can be used by any other .Net Language i.e within .Net Each Langauage can perform Operations with other language with the help of CIL. This feature of.Net is nothing but Interoperability.
For Example , the CIL code which we get after compiling C# Language can be used by VB Language and the CIL Code which we get after compilation of VB code can be used by C#
How is this Possible ?
Though .Net is a collection of languages ,Every language has its own Data Types.C# has its own Data Types and VB.Net has its own Data Types but their sizes are same .After compilation any .Net language CIL Code will be generated which can be used by other Languages of .Net
Examples: After Compiling VB Code, Data Types in that Language will be Converted into CIL Type and it can be used C# and Vice-Versa
VB Datatypes converts to CIL which can be used by C#
VB --------> CIL --------> C#
Integer --> Int32 --------> int
Single --> Single --------> float
Boolean --> Boolean --------> bool
C# Datatypes converts to CIL which can be used by VB
C# ----> CIL --------> VB
Int --> Int32 --------> integer
Float --> Single --------> single
Bool --> Boolean --------> boolean
Language Interoperability is possible because even though DataTypes names are Different in Different .Net Languages their Sizes are same for all .Net Languages but after Compiling they will generate same CIL Code which can be used by any other .Net Languages
Every .Net Language after Compiling Generates CIL Code which can be used in other .Net Langauges
----Proof----
1)Take a New Project
2)Select Language as Visual Basic
3)Select Class Library Template
4)Save it as VB CODE
Why Class Library?
The code which is written in Class Library can't be used for execution but it can used be consumed in other classes.We must build the Class Library so that a dll file will be Generated.
Write the following code
Public Class Class1
Public Sub hitocsharp()
Console.WriteLine("Hi C# ")
End Sub
Public Function ADD(ByVal x As Integer, ByVal y As Integer) As Integer
Return x + y
End Function
End Class
These are important Points
Since we cannot execute the code in Class Library, convert it into an Assembly
1)Open Solution Explorer
2)Right Click on Project i.e VBCODE
3)Select Build
How to use above VBCODE
1)Right Click on VBCODE
2)Select New Project
3)select Visual C#
3)Name it as CSHARPCODE
Right Click on Csharpcode and add a Class csharp 
Now Add the Reference of VBCODE.dll which we have generated before
How to Add Reference files
1)Right Click on the Csharpcode
2)Select Add Reference
3)Browse VBCODE.dll in the VBCODE Project
4)Add VBCODE.dll to your Project
To access the VBCode we must add one statement i.e using VBCODE; because Now it is another Project
Write the Following Code
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using VBCODE;
namespace CHARPCODE
{
class Csharp
{
static void Main()
{
Class1 obj = new Class1();
obj.hitocsharp();
Console.WriteLine( obj.ADD(1,3));
Console.ReadLine();
}
}
}
Now Execute the Csharp.cs 
Observe that you will get the Output of the Class Library
Like this you can Perform Inter Operations between all the Languages in .Net.
Advantage Of Interoperability
With Interoperability you can interact with all the Languages in .Net
We can Save the Time instead of Generating the same Code Again and Again
Note that Language Interoperability can be possible only with the help of CLS(Common Language Specifications) and CLR(Common Language Runtime) of .Net
Hi Reddy,
Thanks for posting such a nice article about Interopability