CODEWITHSUNDEEP
c#arrayslinqdirectoryinfo
pwquigle
pwquigle

Reputation: 47

How do I return a DirectoryInfo object consisting of numeric folder names?

I'm trying to query a folder and return only folders with a numeric folder name. The catch is that I need it in a DirectoryInfo[] object.

I could do it like this (and it works):

List<string> subDirList = Directory.GetDirectories(rootPath, "*", SearchOption.TopDirectoryOnly)
                           .Where(f => Regex.IsMatch(f, @"[\\/]\d+$")).ToList();

But I really need something like this:

DirectoryInfo[] subDirs = Directory.GetDirectories(rootPath, "*", SearchOption.TopDirectoryOnly)
                                   .Where(f => Regex.IsMatch(f, @"[\\/]\d+$"));

Any suggestions?

Upvotes: 2

Views: 267

Answers (2)

willeM_ Van Onsem
willeM_ Van Onsem

Reputation: 476750

You can use a .Select(..) to map it to DirectoryInfo and then use ToArray():

DirectoryInfo[] subDirs = Directory.GetDirectories(rootPath, "*", SearchOption.TopDirectoryOnly)
                                   .Where(f => Regex.IsMatch(f, @"[\\/]\d+$"))
                                   .Select(x => new DirectoryInfo(x)) //convert it to a DirectoryInfo
                                   .ToArray(); // make the result an Array

Upvotes: 5

Mong Zhu
Mong Zhu

Reputation: 23732

Instantiate an object of type DirectoryInfo and then make your query. The method DirectoryInfo.GetDirectories will return the desired array of type DirectoryInfo

DirectoryInfo dirInfo = new DirectoryInfo(yourpath);

DirectoryInfo[] subDirs = dirInfo.GetDirectories("*", SearchOption.TopDirectoryOnly)
                         .Where(f => Regex.IsMatch(f.FullName, @"[\\/]\d+$")).ToArray();

EDIT:

In C# 7 you could avoid using regex with a simple int.TryParse:

DirectoryInfo[] subDirs = dirInfo.GetDirectories("*", SearchOption.TopDirectoryOnly)
                      .Where(f => int.TryParse(f.Name, out _)).ToArray();

below C# 7 you would need an extra variable of type int for the out value

Upvotes: 2

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