Changing C# on the fly (without stopping the debugger) in an ASP .NET vNext web application with Visual Studio 14 CTP3

The roslyn compiler found in Visual Studio 14 enables us, to adjust C# code during runtime, by compiling the new C# code in-memory. Now we can edit the UI part (HTML, CSS, JavaScript) of a single page app, including the backend C# ASP .NET Web Api service dynamically in runtime.

 

On of the things, that disrupts my workflow, when creating a single page app with AngularJS, backed by a web api C# service in Visual Studio 2013, is the fact that, when I find a bug in my C# code while testing the UI, I have to stop the debugger, adjust the web api C# code, re-compile, re-run and then recreating state in the web app before I can resume testing the UI.

This pain will go away, when using Visual Studio 14

 

Download and install Visual Studio 14 CTP 3 from http://msdn.microsoft.com/en-US/subscriptions/downloads/

Open Visual Studio, choose File > New > Project …

 

image

 

image

 

Start the web application by pressing CTRL + F5 (so don’t start the debugger).

 

image

 

Click on the Contact page in the browser:

You will see the text “Your contact page”.

image

 

Now go to the Controllers\HomeController.cs

image

 

Adjust the the C# code: ViewBag.Message = "Your contact page.";

to

ViewBag.Message = "My contact page.";

 

image

 

Save the file and in the browser press F5, you might see a short delay, because the roslyn compiler is now dynamically compiling the code.

 

The C# code is changed without disrupting my workflow.

 

image

One Comment

  1. Sasquatch

    What ever happened to this. Now that we are with .Net Core, this workflow would be highly desirable… but seems to still be lacking in VS 2017

Leave a Reply

Your email address will not be published. Required fields are marked *