Can not Modify web.config file

[pasam]

Hi
I am creating installer for asp.net

i am using this code for to modify web.config file
but i cant whats wrong this code

' Get configuration.
        Dim config As Configuration = WebConfigurationManager.OpenWebConfiguration(System.Web.Hosting.HostingEnvironment.ApplicationVirtualPath)

        ' Find app setting to change
        Dim element As KeyValueConfigurationElement = CType(config.AppSettings.Settings("ConnectString"), KeyValueConfigurationElement)
        If Not element Is Nothing Then
            element.Value = strCon
        End If
        config.Save()

[tlhintoq]

What error message are you getting?

[pasam]

I didnt get any eroor message　when i instaling.

but no modification in web.config file.

[Frinavale]

You need to load the web.config into memory before you can modify it.
It's probably a good idea load it as an XmlDocument so that you can parse it easily and edit the key that you want to.

For example:

'The webConfigLocation variable should be the path to the web.config file.
  Dim webConfigLocation As String = "C:\MyWebAppPath\web.config"
  Dim webConfigDoc As New XmlDocument
  webConfigDoc.Load(webConfigLocation)
  Dim appConfigList As XmlNodeList = webConfigDoc.GetElementsByTagName("add")

   For Each appConfigElement As XmlNode In appConfigList
      Dim key As String
      If Not appConfigElement.Attributes("key") Is Nothing Then
         key = appConfigElement.Attributes("key").Value

'Where "DatabaseConnection" is the name of the key for your Connection String
         If String.Compare(key, "DatabaseConnection", True) = 0 Then
            appConfigElement.Attributes("value").Value = "Some Edited Value"
            Exit For
         End If
      End If
   Next
   webConfigDoc.PreserveWhitespace = True
   webConfigDoc.Save(webConfigLocation)

[pasam]

Thnaks for your code

I will try this