c# - How to change hardcoded variables basing on publish configuration?

Question

I have to publish multiple versions of the same .NET Core 3.1 based console applications, these versions are identical, the only difference between these versions is an hardcoded server address to which they need to connect.

My question is, how I can change the value of an hardcoded variable at compilation time basing on .NET publish configuration?

Answer 1

I agree with the comments that you should use configuration files or environment variables If you still insist to hard code all your values you could do something like that.

Hard code your variables.

public const string UrlDev = "";
public const string UrlProd = "";

and when you are about to use the url you can do like in your app

var url = Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT") == "Development" ? UrlDev : UrlProd

The Environment variables can be passed to your application on publish like this

dotnet publish /p:Configuration=Release /p:EnvironmentName=Development

The line above will create the following snippet in the csproj file

    <environmentVariables>
      <environmentVariable name="ASPNETCORE_ENVIRONMENT" value="Staging" />
    </environmentVariables>

So you publish with Environment vairables already attached on the application and then you make a decision which url to use on this variable.