SharePoint - Set custom publishing page layout custom field programatically

Question

I have a custom publishing page content type, based on the Publishing Article Page content type. On this content type, I have a custom field named "PageContentCategory". In my code to create new pages, I tried this:

PublishingPage newPublishingPage = this.currentPublishingWeb.GetPublishingPages().Add(pageName, newPageSelectedLayout);

if (pageContent.IsEmpty())
{
 pageContent = Properties.Resources.EAWorldArticleHandler_CreateNewArticlePage_DefaultPageContent;
}

newPublishingPage.ListItem[new Guid("{93496B35-7EC3-4132-B0D0-3BDC5606F5EF}")] = pageContentCategory;
newPublishingPage.ListItem[FieldId.PublishingPageContent] = pageContent;
newPublishingPage.Title = pageTitle;
newPublishingPage.Update();

I have also tried to set it by the field name:

PublishingPage newPublishingPage = this.currentPublishingWeb.GetPublishingPages().Add(pageName, newPageSelectedLayout);

if (pageContent.IsEmpty())
{
 pageContent = Properties.Resources.EAWorldArticleHandler_CreateNewArticlePage_DefaultPageContent;
}

newPublishingPage.ListItem["PageContentCategory"] = pageContentCategory;
newPublishingPage.ListItem[FieldId.PublishingPageContent] = pageContent;
newPublishingPage.Title = pageTitle;
newPublishingPage.Update();

Both of these methods throw an error. Is there any way for me to set my custom field's value in code like this?

Answer 1

So, the solution to my problem was that I had to programmatically add the content type to the pages list instead of letting it be added automatically the first time a page with that content type was added. Apparently if you let SharePoint automatically add the content type to the pages list then it somehow doesn't get bound properly. So adding the content type first solved my problem.

Answer 2

Try calling the Update method on newPublishingPage.Listitem not on newPublishingPage itself. Like this:

newPublishingPage.ListItem["PageContentCategory"] = pageContentCategory;
newPublishingPage.ListItem.Update();

and then you maybe also need some of these lines, depending in the configuration of your page library

newPublishingPage.Checkin();
newPublishingPage.Publish();
newPublishingPage.Approve();