how to avoid unauthorized access exception?

Question

The following is my code.

 //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();                    
            }         

so what im doing is taking a list of music and movies and placing there properties into a sql data base but i want it to search all the directory's in the user file. due to the appdata im getting a

System.UnauthorizedAccessException was unhandled.

how can i avoid this? the error is where it is pulling all files from the user folder Josh.

Answer 1

Some files are system files (such as the ones in User folder as in your case like AppData etc). you can either request permission or ignore them

        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);
        }

i suggest you to take a look at 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