返回与部分字符串匹配的目录（文件夹）名称列表

Question

I need someone to point me in the right direction.

Goal:
Return a list of Folder Names in a path that contain a string in their name. For example: The Path has a Directory named Pictures_New and Videos_New. The string I am searching with is "Pictures_" and "Videos_".

It all works with one string parameter being passed as a search string. My problem is getting it to work with multiple filters. I know it is easily done with file names and extensions.

This is being passed to GetFolders() :

string[] filterStrings = { "Pictures_", "Videos_" }

Rest of my code:

public IEnumerable<string> GetFolders(string path, string[] filterStrings, SearchOption searchOption = SearchOption.AllDirectories)
{
    IEnumerable<string> folders = Directory.EnumerateDirectories(path, "Pictures_*.*", searchOption);
    var resultFolders = new List<string>();

    if(filterStrings.Length > 0)
    {
        foreach (var foldername in folders)
        {
            string folderName = Path.GetFileName(Path.GetDirectoryName(foldername));

            if (string.IsNullOrEmpty(folderName) || Array.IndexOf(filterStrings, "*" + folderName) < 0)
            {
                // This leaves us only with the Directory names. No paths.
                var b = (foldername.Substring(foldername.LastIndexOf(@"\") + 1));
                resultFolders.Add(b);
            }
        }
    }
    return resultFolders;
}

Answer 1

You can use Linq SelectMany to parse your list of filters and return a list of the results with Directory.GetDirectories();
It will of course return all the Sub Directories that match the filter. Use just "*".

public IEnumerable<string> GetFolders(string path, string[] filterStrings, SearchOption searchOption = SearchOption.AllDirectories)
{
    List<string> resultFolders = filterStrings
                 .SelectMany(flt => Directory.GetDirectories(path, flt, searchOption))
                 .ToList();
    return resultFolders;
}

Answer 2

try:

var patterns = new[] { "Pictures_*", "Videos_*" };
var dirsFound = new List<string>();
foreach (var dir in patterns.Select(pattern => Directory.GetDirectories(@"my path", pattern).ToArray()))
{
    dirsFound.AddRange(dir);
}

Answer 3

Looks like you're not looping through each of your filter strings:

var folders = new List<string>();
foreach (var filterString in filterStrings)
{
    folders.AddRange(Directory.EnumerateDirectories(path, filterString, searchOption););
}