ASP.NET和VB.NET配置文件

Question

I am trying to share a DLL between an ASP.NET application and a VB.NET (Forms) application. The client application uses a configuration file to store settings eg connection strings and so does the ASP.NET application.

The ASP.NET application uses the System.Web.Configuration namespace whilst the VB.NET application uses the System.Configuration namespace. I notice that they inherit from the Object class. I was expecting them both to inherit from a common class so that I could perhaps use Polymorphism to create an instance of the appropriate type in the DLL.

What is the best practice for using config files for DLLs that are shared across ASP.NET and VB.NET applications. I have researched this and I read somewhere that you should use System.Configuration in the ASP.NET application and I read somewhere else that you should not do this because you cannot write to the web.config if you use System.Configuration in the ASP.NET application. I do not need to write to the web.config; I need to read it. What is the best practice?

Update 13/07/2012 The DLL contains one class. The class currently has one constructor, which looks like this:

private connectionString As Sub
Public Sub New()
connectionString = WebConfigurationManager.ConnectionStrings("TestConnection").ConnectionString
End Sub

I am now thinking about creating another constructor in the class for the none web clients to call ie :

private connectionString As Sub
Public Sub New()
connectionString = connectionString2
End Sub

Answer 1

我建议从宿主应用程序传递你的DLL函数的参数，并从dll中完全删除配置文件依赖项。

Answer 2

What has worked well for us in this case is we put entries in using:

<configuration>
  <appSettings>
    <add key="AccessServer" value="\\apollo\all_access_anon\northwind.mdb" />
    ...

And then we access it using:

NameValueCollection appSettings = ConfigurationManager.AppSettings;
string str = appSettings["AccessServer"];

That is common to both config files.