Public Shared Function IsPublishingWeb ( _
    web As SPWeb _
) As Boolean

Dim web As SPWeb
Dim returnValue As Boolean

returnValue = PublishingWeb.IsPublishingWeb(web)

public static bool IsPublishingWeb (
    SPWeb web
)

using SPContentTypeId = Microsoft.SharePoint.SPContentTypeId;
using SPContentType = Microsoft.SharePoint.SPContentType;
using SPSite = Microsoft.SharePoint.SPSite;
using SPFile = Microsoft.SharePoint.SPFile;
using SPWeb = Microsoft.SharePoint.SPWeb;
using PublishingSite = Microsoft.SharePoint.Publishing.PublishingSite;
using PublishingWeb = Microsoft.SharePoint.Publishing.PublishingWeb;
using PageLayoutCollection = Microsoft.SharePoint.Publishing.PageLayoutCollection;
using PageLayout = Microsoft.SharePoint.Publishing.PageLayout;

namespace Microsoft.SDK.SharePointServer.Samples
{
    public static class PublishingWebCodeSamples
    {
        public static void SetPublishingWebProperties(SPWeb web, System.Guid defaultPageFileId)
        {
            // TODO: Replace these variable values and input parameters
            // with your own values.
            string newTitle = "your Title";                     // new PublishingWeb.Title value
            string newDescription = "your Description";         // new PublishingWeb.Description value
            bool resetInheritPageLayouts = true;                // new PublishingWeb.IsInheritingAvailablePageLayouts value
            bool resetInheritWebTemplates = true;               // new PublishingWeb.IsInheritingAvailableWebTemplates value

            // Validate the input parameters.
            if (null == web)
            {
                throw new System.ArgumentNullException("web");
            }

            // Get the PublishingWeb wrapper for the SPWeb 
            // that was passed in.
            PublishingWeb publishingWeb = null;
            if (PublishingWeb.IsPublishingWeb(web))
            {
                publishingWeb = PublishingWeb.GetPublishingWeb(web);
            }
            else
            {
                throw new System.ArgumentException("The SPWeb must be a PublishingWeb", "web");
            }

            //  Retrieve the SPFile.
            SPFile newDefaultPageFile = publishingWeb.Web.GetFile(defaultPageFileId);
            if( (null == newDefaultPageFile) ||
                !newDefaultPageFile.Exists )
            {
                throw new System.ArgumentException(
                    "The Guid does not match an SPFile on the SPWeb",
                    "defaultPageFileId");
            }

            // Set new values on the PublishingWeb.
            publishingWeb.Title = newTitle;
            publishingWeb.Description = newDescription;
            publishingWeb.DefaultPage = newDefaultPageFile;
            if( resetInheritPageLayouts && 
                !publishingWeb.IsInheritingAvailablePageLayouts  &&
                !publishingWeb.IsRoot)
            {
                publishingWeb.InheritAvailablePageLayouts();
                System.Diagnostics.Debug.Assert(publishingWeb.IsInheritingAvailablePageLayouts);
            }
            if (resetInheritWebTemplates && 
                !publishingWeb.IsInheritingAvailableWebTemplates &&
                !publishingWeb.IsRoot)
            {
                publishingWeb.InheritAvailableWebTemplates();
                System.Diagnostics.Debug.Assert(publishingWeb.IsInheritingAvailableWebTemplates);
            }

            // Save the new values on the PublishingWeb.
            publishingWeb.Update();
        }
    }
}