Question

以下是我的代码。

 //string[] directories; 
        List<string> dirs = new List<string>(Directory.EnumerateDirectories("C:\\Users\\Josh"));
        //string[] Files;

        //directories = Directory.GetDirectories(@"C:\Users\Josh\", "*", SearchOption.AllDirectories);

        SqlConnection myConn = new SqlConnection("Server=Josh-PC;database=Music;User ID=Josh; Password=Climber94; Trusted_Connection=True;");

        string removeText = "Delete from Music.dbo.SongNamesAndInfo";
        SqlCommand RemoveEntry = new SqlCommand(removeText, myConn);

        myConn.Open();

        RemoveEntry.ExecuteNonQuery();

        myConn.Close();

        //for (int d = 0; d < directories.Length; d++)
        foreach (var dir in dirs)
        {                            
            List<string> files = new List<string>(Directory.EnumerateFiles(dir));

            foreach (var file in files)
            {

                FileInfo oFileInfo = new FileInfo(file);

                myConn.Open();

                string cmdText = "Insert INTO Music.dbo.SongNamesAndInfo " +
                        "(Name,dtCreationTime,Extension,Length,DirectoryName)" +
                        "VALUES(@Name,@dtCreationtime,@Extension,@Length,@DirectoryName)";

                SqlCommand addCmd = new SqlCommand(cmdText, myConn);                    
                DateTime dtCreationTime = oFileInfo.CreationTime;

                addCmd.Parameters.AddWithValue("@Name", oFileInfo.Name);                                       
                addCmd.Parameters.AddWithValue("@dtCreationtime", dtCreationTime);                    
                addCmd.Parameters.AddWithValue("@Extension", oFileInfo.Extension);                    
                addCmd.Parameters.AddWithValue("@Length", oFileInfo.Length.ToString());                    
                addCmd.Parameters.AddWithValue("@DirectoryName", oFileInfo.DirectoryName);

                if (oFileInfo.Extension.ToLower() == ".mp3" || oFileInfo.Extension.ToLower() == ".avi" ||                    
                    oFileInfo.Extension.ToLower() == ".mkv" || oFileInfo.Extension.ToLower() == ".m4a" ||                        
                    oFileInfo.Extension.ToLower() == ".aac" || oFileInfo.Extension.ToLower() == ".wav" ||                        
                    oFileInfo.Extension.ToLower() == ".mpa" || oFileInfo.Extension.ToLower() == ".wma" ||                        
                    oFileInfo.Extension.ToLower() == ".flv" || oFileInfo.Extension.ToLower() == ".m4v" ||                        
                    oFileInfo.Extension.ToLower() == ".mpg" || oFileInfo.Extension.ToLower() == ".mov" ||                        
                    oFileInfo.Extension.ToLower() == ".wmv" || oFileInfo.Extension.ToLower() == ".mp4")                        
                {                            
                    addCmd.ExecuteNonQuery();
                }

                myConn.Close();                    
            }

所以我正在做的是获取音乐和电影列表并将属性放入sql数据库但我希望它搜索用户文件中的所有目录。由于appdata我得到了

System.UnauthorizedAccessException未处理。

我怎么能避免这个？错误是从用户文件夹Josh中提取所有文件的地方。

Answer 1

某些文件是系统文件（例如在用户文件夹中的文件，如AppData等）。您可以请求权限或忽略它们

        FileIOPermission f = new FileIOPermission(PermissionState.Unrestricted);
        f.AllLocalFiles = FileIOPermissionAccess.Read;
        try
        {
            f.Demand();
            //your code for processing files
        }
        catch (SecurityException s)
        {
            //cannot get permissions for files.got exception
            Console.WriteLine(s.Message);
        }

我建议你看看Code Access Security https://msdn.microsoft.com/en-us/library/930b76w0(v=vs.85).aspx

https://msdn.microsoft.com/en-us/library/0d005ted(v=vs.90).aspx

Answer 2

使用Directory.EnumerateDirectories一次访问一个文件夹，忽略或记录引发异常的文件夹。这样你就可以得到尽可能多的东西。

如果您想知道如何获得目录的权限，那就是您的用户帐户的权限。

Answer 3

你应该使用枚举Environment.SpecialFolder 请将Environment.GetFolderPath(Environment.SpecialFolder.MyMusic )专门用于音乐文件夹或Environment.GetFolderPath(Environment.SpecialFolder.UserProfile ) + @"\Downloads";等。这是因为理想情况下，您无法访问用户文件夹中Windows资源管理器本身的所有文件夹和子文件夹。这就是抛出异常的地方所以你的代码就是这样的

        string[] directories;
        string[] Files;
        string folder = Environment.GetFolderPath(Environment.SpecialFolder.MyMusic ) ;
        directories = Directory.GetDirectories(folder);

如何避免未经授权的访问异常？

3 个答案: