/// <summary>
/// 访问者模式相关
/// </summary>
/// <param name="visitor"></param>
public void Accept(IFileVisitor visitor)
{
foreach (var item in this._childList)
{
item.Accept(visitor);
}
visitor.Visit(this);
}
/// <summary>
/// Walk through a directory tree start with a root file, and performs <see cref="IFileVisitor.Visit"/> on each walked file
/// </summary>
/// <param name="fileSystemInfo">the root file</param>
/// <param name="visitor">a visitor pattern</param>
/// <exception cref="DirectoryNotFoundException"></exception>
/// <exception cref="SecurityException"></exception>
/// <exception cref="UnauthorizedAccessException"></exception>
public static void WalkFileTree(this FileSystemInfo fileSystemInfo, IFileVisitor visitor)
{
switch (fileSystemInfo)
{
case FileInfo file:
visitor.Visit(file);
return;
case DirectoryInfo directoryInfo:
{
// walk thru directories
var dirRemains = new Stack <DirectoryInfo>();
if (!directoryInfo.Exists)
{
throw new DirectoryNotFoundException(directoryInfo.FullName);
}
dirRemains.Push(directoryInfo);
while (dirRemains.Any())
{
var toWalk = dirRemains.Pop();
foreach (var fileInfo in toWalk.GetFiles())
{
visitor.Visit(fileInfo);
}
foreach (var subDirectory in toWalk.GetDirectories())
{
dirRemains.Push(subDirectory);
}
}
return;
}
default:
throw new ArgumentException($"parameter {nameof(fileSystemInfo)} must be one of {{{nameof(FileInfo)}, {nameof(DirectoryInfo)}}}");
}
}
public static IFileVisitor Walk(string root, IFileVisitor visitor)
{
if (root == null)
{
throw new ArgumentNullException(nameof(root));
}
if (visitor == null)
{
throw new ArgumentNullException(nameof(visitor));
}
if (!System.IO.Directory.Exists(root))
{
throw new ArgumentException($"");
}
var nodes = new Stack <Node>(20);
nodes.Push(new Node(root));
VisitResult result;
while (nodes.Count > 0)
{
Node currentNode = nodes.Peek();
if (currentNode.IsFinished)
{
nodes.Pop();
result = visitor.PostDirectoryVisit(currentNode.Directory);
if (VisitResult.Terminate == result)
{
return(visitor);
}
}
currentNode.IsFinished = true;
bool skipSubDirectories = false;
bool skipFiles = false;
result = visitor.PreDirectoryVisit(currentNode.Directory);
switch (result)
{
case VisitResult.Terminate:
visitor.PostDirectoryVisit(currentNode.Directory);
return(visitor);
case VisitResult.Return:
skipSubDirectories = true;
skipFiles = true;
break;
case VisitResult.SkipDirectories:
skipSubDirectories = true;
break;
case VisitResult.SkipFiles:
skipFiles = true;
break;
}
if (!skipFiles)
{
string[] files = System.IO.Directory.GetFiles(currentNode.Directory);
for (int i = 0; i < files.Length && !skipFiles; ++i)
{
result = visitor.VisitFile(files[i]);
switch (result)
{
case VisitResult.Terminate:
visitor.PostDirectoryVisit(currentNode.Directory);
return(visitor);
case VisitResult.Return:
skipSubDirectories = true;
skipFiles = true;
break;
case VisitResult.SkipDirectories:
skipSubDirectories = true;
break;
case VisitResult.SkipFiles:
skipFiles = true;
break;
}
}
}
if (!skipSubDirectories)
{
string[] subDirs = System.IO.Directory.GetDirectories(currentNode.Directory);
foreach (var subDir in subDirs)
{
nodes.Push(new Node(subDir));
}
}
}
return(visitor);
}
/// <summary>
/// 访问者模式相关
/// </summary>
/// <param name="visitor"></param>
public void Accept(IFileVisitor visitor)
{
visitor.Visit(this);
}
