i have web.config that have more than value like this

i can read this like this

Here's how you can add a key:

    Dim FileLocation As String = "C:\Inetpub\wwwroot\YourProject\web.config"
    Dim NodeLocation As String = "configuration/appSettings"

    'Adds a key and value to the configuration file
    Public Function AddKey(ByVal strKey As String, ByVal strValue As String) As Boolean
        Dim xmlDoc As New XmlDocument
        'Change this to the location of your configuration file
        xmlDoc.Load(FileLocation)
        'Change this if node is different
        Dim appSettingsNode As XmlNode = xmlDoc.SelectSingleNode(NodeLocation)
        Try
            'Check if the node exists before adding it
            If (KeyExists(strKey)) Then
                Throw New ArgumentException("Key name: <" + strKey + "> already exists in the configuration.")
            End If
            'You must have at least one key that can be empty
            Dim newChild As XmlNode = appSettingsNode.FirstChild.Clone
            newChild.Attributes("key").Value = strKey
            newChild.Attributes("value").Value = strValue
            appSettingsNode.AppendChild(newChild)
            xmlDoc.Save(FileLocation )
            Return True
        Catch ex As Exception
            Return False
        End Try
    End Function

    'Determines if a key exists
    Public Function KeyExists(ByVal strKey As String) As Boolean
        Dim xmlDoc As New XmlDocument
        xmlDoc.Load(FileLocation )
        Dim appSettingsNode As XmlNode = xmlDoc.SelectSingleNode(NodeLocation)
        Dim childNode As XmlNode
        For Each childNode In appSettingsNode
            If (childNode.Attributes("key").Value = strKey) Then
                Return True
            End If
        Next
        Return False
    End Function

hi i am tried your concept,but it arise error when execute save  line

 error is;Access to the path is denied

help me

hajaworld@yahoo.co.in 

This may help

Use configSource attribute to manage Web.Config sections in ASP.Net 2.0

http://rizwanshah.blogspot.com/2007/10/use-configsource-attribute-to-manage.html

Here is my web.config file that i'm trying to update dynamically using Hannous code and I receive null as XmlNode. But this works only if i remove xmlns from the web.config. Could you please help me out as it is very urgent for me.

<?xml version="1.0"?>
<configuration xmlns="http://schemas.microsoft.com/.NetConfiguration/v2.0">
  <configSections>
   
  <appSettings>
    <!-- point to the database you want to use-->
    <add key="ConnStr" value="Server=servername; database=databasename;Integrated Security=SSPI;Connect Timeout=0" />
    <!-- specify the full path of the rolespace.xml-->
    <add key="ROLESPACE" value="E:\webroot\OAWebService\oaweb.xml" />
    <add key="TOCLevelDepth" value="3" />
    <add key="SearchMax" value="500" />
  </appSettings>
 
</configuration>

Thanks!!!

To care for the namespace, add the following:

After:

xmlDoc.Load(FileLocation)

Add:

Dim XmlNamespaceManager As System.Xml.XmlNamespaceManager = New System.Xml.XmlNamespaceManager(xmlDoc.NameTable)
XmlNamespaceManager.AddNamespace("ns", "http://schemas.microsoft.com/.NetConfiguration/v2.0")

Hi Thanks for your prompt response. But It did not worked still the value is giving null for appsettingsNode.

In the web.config file the namespace prefix is xmlns(which is reserve key word) and in the code we are using 'ns' as the prefix. Hope coz of this it failed.

Kindly, let me know where i'm going wrong.

Hi,

No that's not the problem. Actually I forgot to tell you that you should add NameSpaceManager to SelectSingleNode, therefore changing:

Dim appSettingsNode As XmlNode = xmlDoc.SelectSingleNode(NodeLocation)

to:

Dim appSettingsNode As XmlNode = xmlDoc.SelectSingleNode(NodeLocation, XmlNamespaceManager)

Hi hannous, I am still not able to succeed and kindly help me to succeed with this problem. Here is my code and xml file.

Imports System.Xml

Dim FileLocation As String = "C:\webroot\web.config"

Dim NodeLocation As String = "configuration/appSettings"

If (x) Then

Else

End If

End Sub

Public Function AddKey(ByVal strKey As String, ByVal strValue As String) As Boolean

'Change this to the location of your configuration file

XmlNamespaceManager.AddNamespace("ns", "http://schemas.microsoft.com/.NetConfiguration/v2.0")

'Change this if node is different

Try

'Check if the node exists before adding it

If (KeyExists(strKey)) Then

End If

'You must have at least one key that can be empty

newChild.Attributes("key").Value = strKey

Return True

Return False

End Try

End Function

'Determines if a key exists

Public Function KeyExists(ByVal strKey As String) As Boolean

Dim childNode As XmlNode

If (childNode.Attributes("key").Value = strKey) Then

Return True

End If

Next

Return False

End Module

 Here is the XML file code:

<?xml version="1.0"?>
<configuration xmlns="http://schemas.microsoft.com/.NetConfiguration/v2.0">

   
  <appSettings>
    <!-- point to the database you want to use-->
    <add key="ConnStr" value="Server=servername; database=databasename;Integrated Security=SSPI;Connect Timeout=0" />
    <!-- specify the full path of the rolespace.xml-->
    <add key="ROLESPACE" value="E:\webroot\OAWebService\oaweb.xml" />
    <add key="TOCLevelDepth" value="3" />
    <add key="SearchMax" value="500" />
  </appSettings>
 
</configuration>

-----------

I am receiving nothing as the value for appsettingsNode variable. Kindly, let me know where i'm going wrong and help me out.

Your problem is that the node "configuration/appSettings" is not being recognized because of the namespace. What you need to do is first go the node "configuration" then go to "appSettings". To do so, set the NodeLocation first to "configuration" (without /appSettings), then, after this line:

Dim appSettingsNode As XmlNode = xmlDoc.SelectSingleNode(NodeLocation, XmlNamespaceManager)

try:

appSettingsNode = appSettingsNode.FirstChild

Then keep the rest of the code as it is. As long as appSettings is the first child node under the configuration node (normal situation), this should work.

Hi hannous. Thanks for your time.

This did not work. Is there any alternative. I'm also trying with System.Configuration namespace but i'm facing the same problem there. Need ur help. Also,let me know when u'll be online (Your gmail/yahoo account) so that we can both work at same time to resolve this issue

I'm sorry you still have one more thing to do, add //ns: before NodeLocation on that previous line, so you'll have:

NodeLocationDim appSettingsNode As XmlNode = xmlDoc.SelectSingleNode("//ns:" + NodeLocation, XmlNamespaceManager)
appSettingsNode = appSettingsNode.FirstChild

I tried your code with this and it worked.