Multiple file-extensions searchPattern for System.IO.Directory.GetFiles
I like this method, because it is readable and avoids multiple iterations of the directory:
var allowedExtensions = new [] {".doc", ".docx", ".pdf", ".ppt", ".pptx", ".xls", ".xslx"};
var files = Directory
.GetFiles(folder)
.Where(file => allowedExtensions.Any(file.ToLower().EndsWith))
.ToList();
var filteredFiles = Directory
.GetFiles(path, "*.*")
.Where(file => file.ToLower().EndsWith("aspx") || file.ToLower().EndsWith("ascx"))
.ToList();
Edit 2014-07-23
You can do this in .NET 4.5 for a faster enumeration:
var filteredFiles = Directory
.EnumerateFiles(path) //<--- .NET 4.5
.Where(file => file.ToLower().EndsWith("aspx") || file.ToLower().EndsWith("ascx"))
.ToList();
Directory.EnumerateFiles in MSDN
I believe there is no "out of the box" solution, that's a limitation of the Directory.GetFiles method.
It's fairly easy to write your own method though, here is an example.
The code could be:
/// <summary> /// Returns file names from given folder that comply to given filters /// </summary> /// <param name="SourceFolder">Folder with files to retrieve</param> /// <param name="Filter">Multiple file filters separated by | character</param> /// <param name="searchOption">File.IO.SearchOption, /// could be AllDirectories or TopDirectoryOnly</param> /// <returns>Array of FileInfo objects that presents collection of file names that /// meet given filter</returns> public string[] getFiles(string SourceFolder, string Filter, System.IO.SearchOption searchOption) { // ArrayList will hold all file names ArrayList alFiles = new ArrayList(); // Create an array of filter string string[] MultipleFilters = Filter.Split('|'); // for each filter find mathing file names foreach (string FileFilter in MultipleFilters) { // add found file names to array list alFiles.AddRange(Directory.GetFiles(SourceFolder, FileFilter, searchOption)); } // returns string array of relevant file names return (string[])alFiles.ToArray(typeof(string)); }