LINQ：字符串[]中的字典

Question

I have to create a dictionary for use in a DropDownListFor based on absolute paths retrieved in a string[]. I want ot know if there's a way to have the key be just the folder name and the value be the full path?

Here's what I have so far:

// read available content folders from FTP upload root
var path = HttpContext.Server.MapPath(System.Configuration.ConfigurationManager.AppSettings["ResearchArticleFTPUploadRoot"]);
var subfolders = System.IO.Directory.GetDirectories(path).ToDictionary(r => r, v => v);           
ViewBag.BodyFolderChoices = new SelectList(subfolders, "Key", "Key");

I tried:

var subfolders = System.IO.Directory.GetDirectories(path).ToDictionary(r => r, v => new { v.Substring(v.LastIndexOf("/"), v.Length-v.LastIndexOf("/"))});

Thinking that grab after the last "/" in the path for the folder name as the Key... doesn't work... Ideas?

Answer 1

using System.IO; // to avoid quoting the namespace everywhere it's used

var subfolderPaths = Directory.GetDirectories(path);
var dictionary = subfolderPath.ToDictionary(p => Path.GetFileName(p), p => p);

Note that GetFileName in this context will return the folder name if you give it a full path to a folder.

Answer 2

You could use DirectoryInfo to do that:

var subfolders = Directory
    .GetDirectories(path)
    .ToDictionary(r => r, v => new DirectoryInfo(v).Name);

EDIT

I am aware that the Key -Properties will be the full path in this case. I did this to make sure you do not have to worry about duplicate keys when changing the operation to search for directories recursively:

var subfolders = Directory
    .GetDirectories(path, "*", SearchOption.AllDirectories)
    .ToDictionary(r => r, v => new DirectoryInfo(v).Name);

which could cause issues if a folder two folders contain a equally named sub folder. If this is not a concern, you can switch the parameters of ToDictionary :

var subfolders = Directory
    .GetDirectories(path)
    .ToDictionary(v => new DirectoryInfo(v).Name, r => r);

Answer 3

坚持使用您的方法，以下工作：

var subfolders = System.IO.Directory.GetDirectories(path).ToDictionary(r => r, v => v.Substring(v.LastIndexOf("\\")+1, v.Length - v.LastIndexOf("\\")-1));