文件遍历的二个算法

1.递归算法：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Diagnostics;

namespace TreeViewTest
{
    public partial class Form1 : Form
    {
        //rootPath as property

        public Form1()
        {
            InitializeComponent();
        }

        private void PopulateTreeView(String rootPath)
        {
            this.treeView1.Nodes.Clear();

            Stopwatch sw = new Stopwatch();
            sw.Start();

            TreeNode rootNode;
            DirectoryInfo dirInfo = new DirectoryInfo(rootPath);

            if (dirInfo.Exists)
            {
                rootNode = new TreeNode(dirInfo.Name,0,1);
                rootNode.Tag = dirInfo;
                GetDirectories(dirInfo.GetDirectories(), rootNode);
                treeView1.Nodes.Add(rootNode);
            }

            label1.Text = sw.Elapsed.ToString();
        }

        private void GetDirectories(DirectoryInfo[] subDirInfos,TreeNode subNode)
        {            
            TreeNode subSubNode;

            foreach (DirectoryInfo subSubDirInfo in subDirInfos)
            {
                subSubNode = new TreeNode(subSubDirInfo.Name,0,1);
                subSubNode.Tag = subSubDirInfo;
                try
                {
                    if (subSubDirInfo.GetDirectories().Length != 0)
                    {
                        GetDirectories(subSubDirInfo.GetDirectories(), subSubNode);
                    }
                }
                catch (UnauthorizedAccessException)
                {
                    continue;
                }
                getFiles(subSubNode);
                subNode.Nodes.Add(subSubNode);                
            }
            getFiles(subNode);
        }

        private void getFiles(TreeNode dirNode)
        {
            TreeNode fileNode;
            DirectoryInfo fileDir = (DirectoryInfo)dirNode.Tag;
            try
            {
                foreach (FileInfo finfo in fileDir.GetFiles())
                {
                    fileNode = new TreeNode(finfo.Name, 2, 3);
                    fileNode.Tag = finfo;
                    dirNode.Nodes.Add(fileNode);
                }
            }
            catch (UnauthorizedAccessException)
            { }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            if (this.folderBrowserDialog1.ShowDialog() != DialogResult.Cancel)
            {
                PopulateTreeView(folderBrowserDialog1.SelectedPath);
            }
            //treeView1.ExpandAll();
        }
    }
}

2.非递归算法：

using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Forms;
using System.Drawing;
using System.IO;
using System.Diagnostics;

namespace WindowsApplication3
{
    class DirTreeAdvance : TreeView
    {
        private int fileCount;
        private int directoryCount;
        private ImageList imageList1;
        private System.ComponentModel.IContainer components;
        private TimeSpan ellapsedTime;

        public DirTreeAdvance()
        {
            InitializeComponent();
            this.ImageList = imageList1;
        }

        public TimeSpan EllapsedTime
        {
            get { return ellapsedTime; }
        }

        public int FileCount
        {
            get { return fileCount; }
        }

        public int DirectoryCount
        {
            get { return directoryCount; }
        }

        public void TraverseFolder(string rootDir)
        {
            Stopwatch sw = new Stopwatch();
            sw.Start();

            //BeginUpdate();
            this.Nodes.Clear();

            Stack<TreeNode> directoryNodeStack = new Stack<TreeNode>();

            DirectoryInfo directoryInfo = new DirectoryInfo(rootDir);
            TreeNode node = new TreeNode(rootDir, 0, 1);
            node.Tag = directoryInfo;
            this.Nodes.Add(node);
            //push into stack
            directoryNodeStack.Push(node);

            while (directoryNodeStack.Count > 0)
            {
                TreeNode currentDirNode = directoryNodeStack.Pop();
                directoryInfo = currentDirNode.Tag as DirectoryInfo;

                try
                {
                    foreach (FileSystemInfo childFileSystem in directoryInfo.GetFileSystemInfos())
                    {
                        node = new TreeNode(childFileSystem.Name);
                        node.Tag = childFileSystem;
                        if (childFileSystem is FileInfo)
                        {
                            node.ImageIndex = 2;
                            node.SelectedImageIndex = 3;
                            fileCount++;
                        }
                        else
                        {
                            node.ImageIndex = 0;
                            node.SelectedImageIndex = 1;
                            directoryCount++;
                            //push into stack
                            directoryNodeStack.Push(node);
                        }
                        currentDirNode.Nodes.Add(node);
                    }
                }
                catch (UnauthorizedAccessException)
                {
                    continue;
                }
            }
            //EndUpdate();

            ellapsedTime = sw.Elapsed;
        }

        private void InitializeComponent()
        {
            this.components = new System.ComponentModel.Container();
            System.ComponentModel.ComponentResourceManager resources = new System.ComponentModel.ComponentResourceManager(typeof(DirTreeAdvance));
            this.imageList1 = new System.Windows.Forms.ImageList(this.components);
            this.SuspendLayout();
            // 
            // imageList1
            // 
            this.imageList1.ImageStream = ((System.Windows.Forms.ImageListStreamer)(resources.GetObject("imageList1.ImageStream")));
            this.imageList1.TransparentColor = System.Drawing.Color.Transparent;
            this.imageList1.Images.SetKeyName(0, "CLOSED.BMP");
            this.imageList1.Images.SetKeyName(1, "OPEN.BMP");
            this.imageList1.Images.SetKeyName(2, "doc.ico");
            this.imageList1.Images.SetKeyName(3, "folder.ico");
            this.ResumeLayout(false);

        }
    }
}