Table of contents

1. Core
   1. Set ENV variable
2. MVC
   1. Set ENV variable
3. C#

---

Core

Set ENV variable

<aspNetCore processPath="%LAUNCHER_PATH%" arguments="%LAUNCHER_ARGS%" stdoutLogEnabled="false" stdoutLogFile=".\logs\stdout"
            forwardWindowsAuthToken="false">
    <environmentVariables>
        <environmentVariable name="ASPNETCORE_ENVIRONMENT" value="QA"/>
        <environmentVariable name="AnotherVariable" value="My Value"/>
    </environmentVariables>
</aspNetCore>

or

set in launchSettings.json

{
  "https": {
    "commandName": "Project",
    "dotnetRunMessages": true,
    "launchBrowser": true,
    "launchUrl": "swagger",
    "applicationUrl": "https://localhost:7278;http://localhost:5277",
    "environmentVariables": {
      "ASPNETCORE_ENVIRONMENT": "Development",
      "GOOGLE_APPLICATION_CREDENTIALS": "C:\\Users\\bp01232023\\source\\repos\\GoogleCloudLogging\\application_default_credentials.json"
    }
  }
}

MVC

Set ENV variable

set in Web.config

<appSettings>
    <add key="ENV" value="DEV"/>
</appSettings>

C#

public class EnvironmentService
    {

        string GetAppSettingValue(string key)
        {
            return ConfigurationManager.AppSettings[key];
        }

        public bool SetEnvironmentVariableFromAppSetting(string envVariableName)
        {
            var envSet = !string.IsNullOrWhiteSpace(Environment.GetEnvironmentVariable(envVariableName));

            if (!envSet)
            {
                var envValue = GetAppSettingValue(envVariableName);
                envSet = !string.IsNullOrWhiteSpace(envValue);

                if (envSet)
                {
                    Environment.SetEnvironmentVariable(envVariableName, envValue);
                    return envSet;
                }
            }

            return envSet;
        }

    }