LINQ - GetDirectories that contain specific files

1 May 2009 7:04 PM

Scott Rymer

I'm currently loading a treeview with a directory tree which excludes user
defined paths:

Private Sub AddFolders(ByVal ParentNode As TreeNode)

    'Load the Folders to exclude from the listview
    Dim xFolders = From f In
XDocument.Parse(My.Resources.ExludeFolders).Descendants("FolderPath") _
                             Select f.Value

    'Get the folders under the ParentNode
    Dim folders = From folder In New
DirectoryInfo(ParentNode.Tag).GetDirectories() _
                         Where Not xFolders.Contains(folder.FullName) _
                          Select folder

     'Add them to the Directory tree
     For Each folder In folders
         Dim N = ParentNode.Nodes.Add(folder.Name)
         N.Tag = folder.FullName
     Next

End Sub

What I would also now like to do is only include folders which contains
specific file types (*.dft) - or exclude ones that don't. I'm trying the
code below but I'm getting warning "Runtime errors might occur when
converting 'System.Collections.Generic.IEnumerable(Of String)' to 'String'"

Dim folders = From folder In New
DirectoryInfo(ParentNode.Tag).GetDirectories() _
                      Where folder.FullName.Contains(From d In
folder.GetFiles("*.dft", SearchOption.TopDirectoryOnly) Select d.FullName) _
                      And Not xFolders.Contains(folder.FullName) _
                      Select folder

Any suggestions?

17 May 2009 8:00 AM

Alexander Mueller

Scott Rymer schrieb:

Show quoteHide quote

> What I would also now like to do is only include folders which contains
> specific file types (*.dft) - or exclude ones that don't. I'm trying
> the code below but I'm getting warning "Runtime errors might occur when
> converting 'System.Collections.Generic.IEnumerable(Of String)' to 'String'"
>
> Dim folders = From folder In New
> DirectoryInfo(ParentNode.Tag).GetDirectories() _
>                      Where folder.FullName.Contains(From d In
> folder.GetFiles("*.dft", SearchOption.TopDirectoryOnly) Select
> d.FullName) _
>                      And Not xFolders.Contains(folder.FullName) _
>                      Select folder
>
> Any suggestions?

"FullName.Contains()" expects a string as its argument.
Your LINQ-subquery "From d In
folder.GetFiles("*.dft", SearchOption.TopDirectoryOnly"
provides an IEnumerable Of string. So that won't work.

If you only want the directories returned that contain *.dft
Any() is a pretty good extension method to do the test:

Dim folders = From folder In _
     New DirectoryInfo(ParentNode.Tag).GetDirectories() _
     Where (From f In folder.GetFiles("*.dft", _
     SearchOption.TopDirectoryOnly)).Any() _
     And Not xFolders.Contains(folder.FullName _
     Select folder

MfG,
Alex