I have a problem which concerns hiding content types in the "Add new item"-Ribbon-Button.
In Visual Studio, I defined 2 custom content types (derived from the default folder content type) and a custom list (in that list I added the 2 custom content types). When I deploy the project, I can open the list in SharePoint and with the help of the "Add new item"-Ribbon-Button, I am able to create folder-items which are defined by the 2 custom content types mentioned before. When I create a folder-item, I can go "into" that folder and create another folder-item. So I get a list of nested folders (first-level-folders, second-level-folders, etc.).
But: within the first-level folder, I want to allow only the creation of folder-items defined by ONE of the two custom content types. That means on the "Add new item"-Ribbon-Button, only ONE custom type should appear.
I can do that manually by going into the context-menu of the titel of the first-level-folder, then I choose "Change Content Type Order" (if that is the right translation ... I have a German SharePoint, there it's called "Reihenfolge der neuen Schaltflächen ändern"), and there, by unchecking the respective checkbox, I am able to change the visibility ot the content types which are shown in the "Add new item"-Ribbon Button.
But how can I do that programmatically? I can't find any propierties in the XML of the content type definition. Isn't there any property which says: "By default, only allow the creation of a specific content type within a folder of THIS content type"? The problem is that in the first level of the list I will have about 900 entries, and I don't want to do the changes manually 900 times.
Mayby someone of you could point me to the right direction?
Thank you! Mike