Automatically run code on referenced assembly during startup?? What is this called?

Question

In .NET, there is something that can automatically run a piece of code in a referenced assembly when the assembly is loaded.

For example, you can have a class decorated with a sort of attribute that lives in project Foo(A Class Library). And project Bar(A Web App) simply references project Foo. When Bar loads, that decorated code in Foo gets run somehow. I believe this is a newer feature.

Can someone tell what this feature is called??

Update: Thanks Shiva! Not Module Initialize. Although it lead me to the right answer. PreApplicationStartMethod and it's supported in .NET! Thanks all!!

That's what I'm trying to figure out. I've come across it twice in the last year and thought it was really cool. Now for the life of me I can't recall or google this. — Levitikon, Nov 04 '13 at 19:36
but are you sure this exist? I don't think so it exit(atleast in c#). I did some research some time back. Can't get anything. — Sriram Sakthivel, Nov 04 '13 at 19:38
Be ware - this can cause problems with loader locks. I think that may be part of the reason it is not widely supported. You are better off writing some simple reflection code to look for a class with an attribute and instantiate that in a model similar to what the nunit framework does. — Neil, Nov 04 '13 at 19:44
Good to read you've found it, you might want to add it as an answer so we can vote for it. — Jos Vinke, Nov 04 '13 at 19:58
Since it turns out this was actually an ASP.NET question and that the answer was not module initializers I'm voting to reopen this. — J..., Nov 05 '13 at 11:25

score 8 · Accepted Answer · answered Nov 04 '13 at 20:02

8

Turns out I was looking for PreApplicationStartMethod! Thanks all!

answered Nov 04 '13 at 20:02

Levitikon

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If this is specific for ASP.NET then I'll suggest you to add appropriate tag and some text in your question. That will hep google to find this page(is what I believe). – Sriram Sakthivel Nov 04 '13 at 20:04
The link for PreApplicationStartMethod above no longer exists. However, a simple google search will yield some good results. – David Nov 03 '20 at 13:07

score 3 · Answer 2 · edited May 23 '17 at 12:22

3

Do you, by chance, mean Module Initializer? They are capable of things you describe, but it seems that they are not supported in C#. They are a part of CLR yes, but not a part of C# language itself.

Some links with further information and research:

http://blogs.msdn.com/b/junfeng/archive/2005/11/19/494914.aspx

Module initializers in C#

.Net: Running code when assembly is loaded - thanks to J... for pointing out this link

edited May 23 '17 at 12:22

Community

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answered Nov 04 '13 at 19:41

Ondrej Janacek

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This is basically Hans's answer from here : http://stackoverflow.com/questions/505237/net-running-code-when-assembly-is-loaded – J... Nov 04 '13 at 19:47
Turns out I was looking for PreApplicationStartMethod! Thanks though! – Levitikon Nov 04 '13 at 19:58

score 3 · Answer 3 · answered Nov 04 '13 at 19:50

You might have also have a look at Fody. Fody is "an Extensible tool for weaving .net assemblies" which you can install as a nuget package. There is an add-in for fody called Module Initializers. Which under the hood uses the, in other answers already mentioned module initializers, but takes away the plumping.

From the documentation:

What it does: Finds a class, in the target assembly, named ModuleInitializer with the following form:

public static class ModuleInitializer
{
    public static void Initialize()
    {
        //Init code
    }
}

It then Injects the following code into the module initializer of the target assembly. This code will be called when the assembly is loaded into memory

static <Module>()
{
    ModuleInitializer.Initialize();
}

Turns out I was looking for PreApplicationStartMethod! Thanks though! — Levitikon, Nov 04 '13 at 20:01

score 2 · Answer 4 · answered Nov 04 '13 at 19:42

2

If am not wrong then you're looking for "Module Initializer". Check this out

answered Nov 04 '13 at 19:42

Sriram Sakthivel

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Turns out I was looking for PreApplicationStartMethod! Thanks though! – Levitikon Nov 04 '13 at 20:00

score 1 · Answer 5 · answered Nov 04 '13 at 19:42

1

Are you looking for Module Initializers?

answered Nov 04 '13 at 19:42

Shiva

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Turns out I was looking for PreApplicationStartMethod! Thanks though! – Levitikon Nov 04 '13 at 19:59

Automatically run code on referenced assembly during startup?? What is this called?

5 Answers5