DirectoryInfo.GetFiles() multiple file extensions

[MadHatter]

namespace PathSearch {
    public class FileSearch {
        ArrayList _extensions;
        bool _recursive;
        public ArrayList SearchExtensions {
            get { return _extensions; }
        }
        public bool Recursive {
            get{return _recursive;}
            set{_recursive = value;}
        }
        public FileSearch(){
            _extensions = ArrayList.Synchronized(new ArrayList());
            _recursive = true;
        }
        public FileInfo[] Search(string path) {   
            DirectoryInfo root = new DirectoryInfo(path);
            ArrayList subFiles = new ArrayList();
            foreach(FileInfo file in root.GetFiles()) {
                if(_extensions.Contains( file.Extension )) {
                    subFiles.Add(file);
                }
            }
            if(_recursive) {
                foreach(DirectoryInfo directory in root.GetDirectories()) {
                    subFiles.AddRange( Search(directory.FullName) );
                }
            }
            return (FileInfo[])subFiles.ToArray(typeof(FileInfo));
        }
    }
}

usage:

FileSearch searcher = new FileSearch();
searcher.SearchExtensions.Add(".dll");
searcher.SearchExtensions.AddRange( new string[] {".txt", ".asp", ".exe"} );

FileInfo[] files = searcher.Search("C:\\");