.NET DLL Settings and Config when there's a Web Reference - whats going on?

.net configuration web-config app-config web-reference
codeulike picture codeulike · Oct 21, 2009 · Viewed 11.4k times · Source

My understanding is, that .NET doesn't really 'do' config files for DLLs - only the main Executable or Web App gets a config file, and all DLLs referenced by the Executable/Web App read from that.

But in VS2008, if you add a Web Reference to a Class Library (DLL) project, it adds a Settings.Settings file and an app.config file to the project. They contain the main URL for the Web Reference.

So what are these files for? There's no way for the DLL to read them unassisted, right?

edit: the contents of the app.config and Settings.Settings seem to make a difference though: changing (for example) the Web Reference URL in the DLL Project's app.config file on its own makes no difference, but if you edit the URL in the app.config and then open the Settings.Settings file, the changes you made in app.config then get copied into Settings.Settings. And then, the DLL picks up the new value at run time. How is it doing this?

edit: Part of my confusion here is because I'm not too clear on the difference between Settings.Settings and app.config and how they relate to each other, so maybe people can help out with that issue too.

Answer

Damien_The_Unbeliever picture Damien_The_Unbeliever · Oct 21, 2009

There's no way for the DLL to read them, but they're strong hints to a consumer of your DLL of what they might want to include in the real Settings/Config file

Edit

In response to the comment by OP - Whatever is last edited in the settings gets compiled into the code as a default to take if no setting of the correct name is present at runtime. So that's why that's working.

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