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Why automatic recompile doesn't work for C# classes in Visual Studio asp.net core mvc project?

I have an ASP.Net Core MVC simple project. When I start it without debugging (Ctrl + F5) and change any .cs File (Controller, for example), save it, and update the page in browser nothing happens. But it should automatically recompile and show changes, that was said in the book that I read.
Why can this happen?
I use Visual Studio 2019, .Net core 2.1.
If I manually close the page, and press start without debugging again it recompile and show changes in browser.
If I change .cshtml files (View) it takes effect as soon as I update the browser Page. So it is problem only with C# classes.
UPD dotnet watch works just fine for that purpose, but author of the book (A.Freeman, Pro ASP.Net core MVC 2 7th edition, chapter 6) did not use it:
Visual Studio supports detecting changes as soon as an HTTP request is received from the browser and recompiling classes automatically. To
see how this works, select Start Without Debugging. Once the browser
displays the application data, make the changes to the Home
controller. Save the changes to the controller class file and reload
the browser window without stopping or restarting the application in
Visual Studio. The HTTP request from the browser will trigger the
compilation process, and the application will be restarted using the
modified controller class
Why does this not work for me?

The book was written for Visual Studio 2017. It works as the book describes in VS 2017.
However, according to this, the auto-rebuild feature has not yet been added to Visual Studio 2019.
Original answer: (which applies when that feature is not available):
The difference is that .cs files are compiled into your project's DLL at compile time. For any new code to take effect, the DLL needs to be updated, which will only happen if you specifically tell it to recompile. This is why, when you deploy your project, you copy over the .dll file and not the .cs files.
However, views (.cshtml files) stay as plain text files and are compiled when you use them. If you edit a .cshtml, it's recompiled the next time the view is used. This is why, when you deploy your project, you do need to copy the .cshtml files.
Visual Studio does have a feature to let you modify .cs files while debugging and have it take effect immediately, but it doesn't support ASP.NET projects. It's called Edit and Continue.
However, you can setup dotnet watch to detect file changes and restart your application. There are instructions on how to do that here: Develop ASP.NET Core apps using a file watcher

ASP.NET Application won't notice changes on a .cs-File

I'm developing an asp.net application atm and it will be used to insert some data in a database.
Yesterday, I noticed that I've written the wrong table name in one of my insert statements. Ofc I changed it then, but..!
After getting the same "Unknown Column" exception again and again, I opened the SQL Profiler today and looked at the statement. The statement still tries to insert into the wrong table, but not in the "new" right one, which I've actually written in the code.
Why is the application not noticing changes? I tried to load the website without cache by hitting STRG+F5 for like 125392 times. I also deleted the cache folder, also without success.
Thanks in advance!
Edit: U may want to know that this application is running on a server. Therefore I need to edit the .cs-Files with Notepad because there is no Visual Studio installed on this server.

Are you sure this is running as a website project and not a web application?
If it's running as a website project then editing the .cs files should be picked up. The quickest way to check this would be to introduce a deliberate syntax error to prevent a class from compiling.
Web application projects are compiled before deployment. If there's a .cs file in the web folder for that then it's been deployed by a quick copy-paste rather than a proper publish from Visual Studio and, while the site should work just fine, changes to the .cs files will be ignored. As that's a compiled project you'd need to make the changes somewhere that has access to a compiler (ideally VS on your usual dev machine but I think you could use the command line compiler), then deploy those changes - ideally via a publish to leave the project in a clearer state for the next maintainer :-) If you have to do it manually for whatever reason though, remember you need the .aspx/.ashx etc or .cshtml / .vhbtml files and the DLLs.

.cs files need to be compiled for changes to be added to running library. It is not recommended to edit files directly on the server.

Browser Not Refreshing Without Rebuilding Project ASP.NET 5.0

I am trying out ASP.NET 5.0 Visual Studio Community 2015.
I have a standard Web Application and just going through the tutorial to get familiar with ASP.NET 5.0
The tutorial states
"Save the file and, without rebuilding the project, refresh your web browser. You should see the updated text. ASP.NET 5 no longer requires that you manually build your server-side logic before viewing it, making small updates much faster to inspect during development."
http://docs.asp.net/en/latest/tutorials/your-first-aspnet-application.html
I tried it and it is not working for me. I noticed when I save the file the break points are now disabled. When I reload the page it does not show the change. Is there a setting or configuration that I am missing to allow this to happen?

Make sure you start the project without debugging (Ctrl + F5 in VS instead of F5). The compile on the fly doesn't work with a debugger attached

Web project Debugging & Coding in Visual Studio 2012

I have a web project in Visual Studio.
When at work i can start the project in debug mode (F5), and set break points. Edit the Code Behind or asp controls. When pressing F5, this will refresh and my new code will be represented.
At my home computer i can edit, i can press F5, but my changes will not be shown. And the debugger will step through the code like it does not realize that it has come some new code.
Has anyone experienced this before? This is not the first time I have seen this, but i cant for the life of me figure out how to make it refresh....
Any pointers will be welcome :)
Edit:
Could this by any chance have something to do about the project type? Or the compilation of the web project?

I figured out why this worked as it did.
The project type i had chosen for my project was ASP.NET WEb Forms Application. This implies that the project will compile and be run from an DLL file.
To rebuild this everytime there is made a change is not possible, so it doesn't.
I changed the project type and buildt a Web Site instead. This kind of project does not compile into a DLL, but is rather run on the fly from the files that i code. Because of this i can make changes to my files, hit f5 and it will automatically reload with the new content.

Do I need the bin\debug\appName.vshost.exe and appName.vshost.manifest in my SVN code repository?

I am building an application which is based on a sample application,
written in C# on .NET 2, and is built on VS2008. This application is mostly a wrapper for a COM application.
However I compile it in .NET 3.5.
The sample application came with the following files in it's bin\debug:
appName.vshost.exe
appName.vshost.exe.manifest
I noticed that I can delete the files and VS re-builds vshost.exe, and the vshost.manifest file appears with modification date the same as the deleted file as if VS has copied in from somewhere.
My question is, should I put this files in my SVN code repository?

Those two files you list implement the Visual Studio "hosting process". It is a hosted version of the CLR, designed to improve the debugging experience. It takes care of some security issues, the most visible side-effect is that it redirects output written with Console.WriteLine() in a GUI app to the Output window.
These files are not part of your project and do not get deleted when you use Build + Clean. In fact, you cannot delete the .exe file, it is always running while you've got the project opened in Visual Studio. You can disable the hosting process feature with Project + Properties, Debug, scroll down, "Enable the Visual Studio Hosting process" tick. There's no compelling reason to do so.
There's no need to check these in, Visual Studio re-generates them when you check-in a project and load it in VS. In general, you never need to check anything in from the bin subdirectory, its content is always re-created by building your project.

Everything in the debug (or release) folder is generated. Everything that's generated shouldn't be checked in.
When in doubt, just make a fresh checkout to some other folder (or even machine), and try to build from that. If something is missing, this will find it.

I do not think you should. They are for VS use only.

Here are the files I ignore when creating C# projects. You really only want to store the source code in the repository and not the outputs. Similarly you probably do not want to store the user based information that goes along with VS solutions.
*.csproj.user
*.suo
bin (folder)
obj (folder)