C# Recursive traversal folder example

/// <summary>
/// Recursively obtain files in the folder directory
/// </summary>
/// <param name="pathName">Folders that need to be recursively traversed</param>
/// <param name="fileRule">Transaction rule "Delegation"</param>
public static void LoopFolder(string pathName, Action<FileInfo> fileRule)
{
if ((pathName))
throw new ArgumentNullException(pathName);

Queue<string> _pathQueue = new Queue<string>();
_pathQueue.Enqueue(pathName);
while (_pathQueue.Count > 0)
{
string _path = _pathQueue.Dequeue();
DirectorySecurity _pathSecurity = new DirectorySecurity(_path, );
if (!_pathSecurity.AreAccessRulesProtected)//Is the folder permission accessible?
{
DirectoryInfo _directoryInfo = new DirectoryInfo(_path);
foreach (DirectoryInfo diChild in _directoryInfo.GetDirectories())
{
_pathQueue.Enqueue();
}
foreach (FileInfo file in _directoryInfo.GetFiles())
{
fileRule(file);
}
}
}
}