FileInfo因FileNotFoundExcpeption而失败

Question

当我尝试获取FileInfo（路径）时，我得到一个FileNotFoundException。具体路径为C：\ Windows \ System32 \ DbcSvc.exe。 C：\ Windows \ System32文件夹中的许多其他文件也会发生同样的异常。

起初我以为可能是Windows或System32文件夹被标记为System属性。奇怪的是，这些文件夹都没有标记为系统。

有趣的是，当我尝试使用Windows资源管理器查看文件属性时，我可以看到一切都很好。当我尝试从代码中获取FileInfo时，它失败了。

当我尝试获取DirectoryInfo时，我也在System32中的各种文件夹上获得AccessDenied异常。

我已经尝试使用FileInfo / Directory信息方法以及PInvoke方法GetFileAttributesEx。他们都以同样的方式失败。

Answer 1

您必须递归搜索文件夹以防止访问错误。如果不这样做，您将无法在首次访问异常后继续。见下面的代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
using System.Xml.Linq;
using System.IO;

namespace SAveDirectoriesXml
{
    class Program
    {
        const string FILENAME = @"c:\temp\test.xml";
        const string FOLDER = @"c:\temp";
        static XmlWriter writer = null;
        static void Main(string[] args)
        {
            XmlWriterSettings settings = new XmlWriterSettings();
            settings.Indent = true;

            writer = XmlWriter.Create(FILENAME, settings);
            writer.WriteStartDocument(true);

            DirectoryInfo info = new DirectoryInfo(FOLDER);
            WriteTree(info);

            writer.WriteEndDocument();
            writer.Flush();
            writer.Close();
            Console.WriteLine("Enter Return");
            Console.ReadLine();

        }
        static long WriteTree(DirectoryInfo info)
        {
            long size = 0;
            writer.WriteStartElement("Folder");
            try
            {
                writer.WriteAttributeString("name", info.Name);
                writer.WriteAttributeString("numberSubFolders", info.GetDirectories().Count().ToString());
                writer.WriteAttributeString("numberFiles", info.GetFiles().Count().ToString());
                writer.WriteAttributeString("date", info.LastWriteTime.ToString());


                foreach (DirectoryInfo childInfo in info.GetDirectories())
                {
                    size += WriteTree(childInfo);
                }

            }
            catch (Exception ex)
            {
                string errorMsg = string.Format("Exception Folder : {0}, Error : {1}", info.FullName, ex.Message);
                Console.WriteLine(errorMsg);
                writer.WriteElementString("Error", errorMsg);
            }

            FileInfo[] fileInfo = null;
            try
            {
                fileInfo = info.GetFiles();
            }
            catch (Exception ex)
            {
                string errorMsg = string.Format("Exception FileInfo : {0}, Error : {1}", info.FullName, ex.Message);
                Console.WriteLine(errorMsg);
                writer.WriteElementString("Error",errorMsg);
            }

            if (fileInfo != null)
            {
                foreach (FileInfo finfo in fileInfo)
                {
                    try
                    {
                        writer.WriteStartElement("File");
                        writer.WriteAttributeString("name", finfo.Name);
                        writer.WriteAttributeString("size", finfo.Length.ToString());
                        writer.WriteAttributeString("date", info.LastWriteTime.ToString());
                        writer.WriteEndElement();
                        size += finfo.Length;
                    }
                    catch (Exception ex)
                    {
                        string errorMsg = string.Format("Exception File : {0}, Error : {1}", finfo.FullName, ex.Message);
                        Console.WriteLine(errorMsg);
                        writer.WriteElementString("Error", errorMsg);
                    }
                }
            }

            writer.WriteElementString("size", size.ToString());
            writer.WriteEndElement();
            return size;

        }
    }
}