Fetching dynamically updated connection string from app.config in VB.Net

Question

I have a connection string as follows in app.config

<add name="CONN" connectionString="SERVER=SERVER\SQLEXPRESS;DATABASE=TRIAL_LINK;uid=sa;pwd=trial"
        providerName="System.Data.SqlClient" />

I have a form called DBLinker where i am giving an option to the user to select some other server and database. For instance i am selecting Server name as "MAILSERVER" and database as "Actual". I am overwriting the app.config file using the following code.

Dim config As System.Configuration.Configuration = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None)

Dim mySection As ConnectionStringsSection = DirectCast(config.GetSection("CONN"),ConnectionStringsSection)
Dim conStr As String = "SERVER=MAILSERVER;DATABASE=Actual;uid=sa;pwd=trial"

config.ConnectionStrings.ConnectionStrings("CONN").ConnectionString = conStr
config.Save(ConfigurationSaveMode.Full)


ConfigurationManager.RefreshSection(config.AppSettings.SectionInformation.Name)

After this code i am trying to open a login form for the application. But when i am trying to access connection string here, it is fetching the former string instead of the updated one.

Answer 1

How to programmatically override web.config settings

It looks like you can't alter web.config at Runtime and have it take effect while the application is running. You can get around this by maybe having a setting be the base part of the string and then use the user selection to build the rest. You can always save the new string in Session, cookie or a Db to keep it handy when you need it, depending on your needs.

Hope this helps.