SharePoint 2010 - Programmatically create a folder in document libraries and lists

Maybe this was easy for everyone else but I have to admit that this wasn’t easy for me. As you may know I have developed a tool for SharePoint 2010 Site Provisioning in order to enhance the SharePoint development process which wasn’t able to programmatically create folders and subfolder in a document library or list.

So while I tried to change this I had a lot of trouble to achieve my goal.

Programmatically create a folder in a document library

This is the desired result:

I was able to successfully create a folder in a document library using this code:

SPList list = web.Lists.TryGetList("ListTitle");

SPFolderCollection folderColl = list.RootFolder.SubFolders;
SPFolder newFolder = folderColl.Add(FolderUrl);

FolderUrl means one of the following:

• "/Document Library/Folder1"
  Creates a folder named “Folder1” under “Document Library”…
• "/Document Library/Folder1/Folder11"
  Creates a folder named “Folder11” under “Folder1” in “Document Library”…
• "/Subsite/Document Library/Folder1"
  Creates a folder named “Folder1” under “Document Library” in a sub site…
• "/Subsite/Document Library/Folder1/Folder11"
  Creates a folder named “Folder11” under “Folder1” in “Document Library” in a sub site…

You need to use an URL including the name of the new folder which is different to creating a folder in a list.

Programmatically create a folder in a list

So after we can create a folder in a SharePoint document library we now can create them in SharePoint lists.

This is the desired result:

I was able to successfully create a folder in a SharePoint list using this code:

SPList list = web.Lists.TryGetList("ListTitle");

SPListItem newFolderItem = list.Items.Add(completeFolderUrl, SPFileSystemObjectType.Folder);
newFolderItem["Title"] = "TitleOfTheFolder";
newFolderItem.Update();

completeFolderUrl means one of the following:

• "/lists/Custom List"
  The folder is created under “Custom List”…
• "/lists/Custom List/Folder1"
  The folder is created under “Folder1” in “Custom List”…
• "/aboutus/lists/Custom List"
  The folder is created under “Custom List” in a sub site…
• "/aboutus/lists/Custom List/Folder1"
  The folder is created under “Folder1” in “Custom List” in a sub site…

Important: The folder didn’t create for me when my “completeFolderUrl” ended with a slash ‘/’.

Summary

I don’t know if I’m the only one who had problems to programmatically create folders and subfolder in a document library or list but I hope this helps someone else before you bang your head against the wall or table.

Hope you like it...