Is there any way to initialize the web.config in C# interactive?

Question

I have a ASP.NET MVC project which I am currently working on. I want to try some code in C# interactive, I click on "Initialize interactive with project." I can see the variables, classes and other thing in c# interactive.

Now one thing is broken is static variable that is defined through web.config is throwing exception.

If I paste the code (in interactive window) that is using web.config variable is not working. Anyway to fix this issue.

I check the answer by SeM and I check the appsettings it's have nothing

update 2:

I setup the code on github with reading appsettings as given in answer, still didn't work, code is here https://github.com/anirugu/CsharpInteractiveTesting

What prevents you to define your static variable inside the code? Also, what exception it throws? — SᴇM, Apr 27 '18 at 05:23
If I execute the code, it's saying "The type initializer for 'abc.Globals' threw an exception." — Anirudha Gupta, Apr 27 '18 at 05:40

score 5 · Answer 1 · answered Apr 27 '18 at 08:10

C# interactive itself runs as a separate application with separate application configuration file. If you run this in C# interactive:

AppDomain.CurrentDomain.SetupInformation.ConfigurationFile

You will see something like:

"<path to VS>\\CommonExtensions\\Microsoft\\ManagedLanguages\\VBCSharp\\InteractiveComponents\\InteractiveHost.exe.Config"

So that's the config file being used. Of course it does not contain your variables, so code trying to do ConfigurationManager.AppSettings["foo"].ToString() fails.

Usual way to set config file at runtime is:

AppDomain.CurrentDomain.SetData("APP_CONFIG_FILE", fullPathToYourConfig);

However, this should be done before any access to configuration file. When first access is made - file is being cached and subsequent changes to path will have no effect. Unfortunately, before giving you access to executing commands, C# interactive already works with that file.

There are various hacks with reflection to reset that cache. For example (copied verbatim from here):

public static void ChangeConfigTo(string path)
{
    AppDomain.CurrentDomain.SetData("APP_CONFIG_FILE", path);
    typeof(ConfigurationManager)
        .GetField("s_initState", BindingFlags.NonPublic |
            BindingFlags.Static)
        .SetValue(null, 0);

    typeof(ConfigurationManager)
        .GetField("s_configSystem", BindingFlags.NonPublic |
            BindingFlags.Static)
        .SetValue(null, null);

    typeof(ConfigurationManager)
        .Assembly.GetTypes()
        .Where(x => x.FullName ==
            "System.Configuration.ClientConfigPaths")
        .First()
        .GetField("s_current", BindingFlags.NonPublic |
            BindingFlags.Static)
        .SetValue(null, null);
}

With all that in mind, if you put that function in Program class in your sample on github and do this in C# interactive:

Program.ChangeConfigTo(Path.GetFullPath("app.config"));

Your code will work as you expect. You can put this hack in separate script (.csx) file and load it with "#load" if necessary.

SᴇM · Accepted Answer · 2018-04-27T06:35:44.860

2

For example, if you add your setting into config file

<appSettings>
    <add key="Test" value="Test"/>
</appSettings>

and try to read it by ConfigurationManager, it will throw exception of missing reference or

The name 'ConfigurationManager' does not exist in the current context

In C# interactive window you can reference assemblies with keyword #r

#r "System.Configuration"

and then you can get your value:

#r "System.Configuration"
var settings = ConfigurationManager.OpenExeConfiguration(@"bin\Debug\YourAppName.dll"); //You can use .exe files too
Console.WriteLine(settings.AppSettings.Settings["Test"].Value);

Also! You can add project's all references by right click to your project -> Initialize Interactive with Projcet and VS will do all for you.

Update

For your example:

using System.Configuration;
var settings = ConfigurationManager.OpenExeConfiguration(@"D:\TestProjects\CsharpInteractiveTesting-master\CsharpInteractiveTesting-master\CsharpInteractiveTesting\bin\Debug\CsharpInteractiveTesting.exe");
Console.WriteLine(settings.AppSettings.Settings["foo"].Value);

edited Apr 27 '18 at 06:35

answered Apr 27 '18 at 05:40

SᴇM

7,024
3
24
41

In ASP.NET MVC 5 I tried initializing the interactive, When I am reading the value it's throwing an exception "The type initializer for 'abc.Globals' threw an exception." – Anirudha Gupta Apr 27 '18 at 05:41
Please check the `InnerException` property of the `TypeInitializationException`, it will tell more about your exception. – SᴇM Apr 27 '18 at 05:44
I update the question with an image, It looks like nothing has been initialized from web.config Is there anyway to get those value in c# interactive or I am missing a part to get this thing done. – Anirudha Gupta Apr 27 '18 at 05:45
1

@Adrian please post text, not image. – SᴇM Apr 27 '18 at 05:45
@Adrian I update the question with github link, still not working. – Anirudha Gupta Apr 27 '18 at 06:00
@Adrian I've updated the answer, please try this method too. – SᴇM Apr 27 '18 at 06:04
It's inaccessible due to protection level. I will try it soon. give me sometime. thanks for help – Anirudha Gupta Apr 27 '18 at 06:38

Is there any way to initialize the web.config in C# interactive?

2 Answers2

Update