Protection from reverse engineering of a .NET application

As Nishant Said, There is not any absolute way to protect your program. you can only make your code difficult and more difficult.

Everyone worries about this. The odds that you've created something so groundbreaking that people will be trying to steal it, are low, but if that's really the case, then there's no real protection. You'd be better off to use C++, if you're that worried.

My answer is just same like the given answers you need to use Obfuscator because some protection is much better than no protection. so if you worry about protection of your code then you should use strong programming against reverse engineering you need to use Encryption,code splitting,multiple level of protection like Symbol renaming,string encryption,control flow which can make provide protection of your code.
you can navigate this link[^] having same question with some solution which embedding some perfect links like this one[Protecting .net code with SLPS][^]
you can also take a look on CP article. have go there[Protect your Code from Prying Eyes and Theft]
[^]

EazFuscator

Brilliant product totally customizable.

possible to decompile but near impossible to figure out what the code does.

It encrypts, clear text string it can merge assemblies, embed you assemblies all in one go.

and the best part it is 100% free and easy to use. but plz donate software like this needs support

You need to obfuscate your .net assemblies to prevent this.

Use Crypto Obfuscator - good protections, easy to use and has advanced features like msbuild support, resigning, etc.

I would recommend using AuthGuru as it encrypts the exe code and is much better than using obfuscation.

UNPROTECTED http://i.stack.imgur.com/hI15Y.png

PROTECTED http://i.stack.imgur.com/dbVui.png