获取文件夹的根目录+1

Question

How can i get the root directory of a folder +1?

Example: Input: C:\\Level1\\Level2\\level3 output should be:

Level1

If input is Level1 output should be Level1

if input is C:\\ output should be empty string

Is there is a .Net function handles this?

Directory.GetDirectoryRoot will always returns C:\\

Answer 1

You can use the Path -class + Substring + Split to remove the root and get the top-folder.

// your directory:
string dir = @"C:\Level1\Level2\level3";     

// C:\  
string root = Path.GetPathRoot(dir); 

// Level1\Level2\level3:
string pathWithoutRoot = dir.Substring(root.Length);       

// Level1
string firstFolder = pathWithoutRoot.Split(Path.DirectorySeparatorChar).First(); 

Another way is using the DirectoryInfo class and it's Parent property:

DirectoryInfo directory = new DirectoryInfo(@"C:\Level1\Level2\level3");
string firstFolder = directory.Name;
while (directory.Parent != null && directory.Parent.Name != directory.Root.Name)
{
    firstFolder = directory.Parent.Name;
    directory = directory.Parent;
}

However, i would prefer the "lightweight" string methods.

Answer 2

string dir = @"C:\foo\bar\woah";
var dirSegments = dir.Split(new char[] { Path.DirectorySeparatorChar }, 
                            StringSplitOptions.RemoveEmptyEntries);
if (dirSegments.Length == 1)
{
    return string.Empty;
}
else
{
    return dirSegments[0] + Path.DirectorySeparatorChar + dirSegments[1];
}

Answer 3

Not sure whether this is the correct way but you do:

string s = @"C:\Level1\Level2\Level3";
string foo = s.split(@"\")[1];

Not sure whether DirectoryInfo object can get this in a cleaner manner..

DirectoryInfo di = new DirectoryInfo(@"C:\Level1\Level2\Level3");
di.Root;

Answer 4

You could use DirectoryInfo and a while loop.

DirectoryInfo info = new DirectoryInfo(path);
while (info.Parent != null && info.Parent.Parent != null)
    info = info.Parent;
string result = info.FullName;

Answer 5

One possible solution, but may not be the best, is to find the position of @"\\", and do some manual processing yourself. Below code is not fully tested, just snippet:

//var positions = inputString.IndexOfAny(new [] {'\'});  //Original one
//Updated, thanks to Snixtor's implementation 
var positions = inputString.IndexOfAny(new [] {Path.DirectorySeparatorChar}); 
int n=positions.Length;
if(n>=1)
{
     var pos = positions[1];  //The 2nd '\';
     return inputString.SubString(0, pos);
}
return null;

Of course, this only works if we are sure we want chop substrings after the 2nd '\\'.

Answer 6

You could loop up using the directory info class using the following structure by adding the code section below into a method

string path = "C:\Level1\Level2\level3";
DirectoryInfo d = new DirectoryInfo(path);
while (d.Parent.FullName != Path.GetPathRoot(path))
{
    d = d.Parent;
}
return d.FullName;

Answer 7

一个快乐的linq one liner：

string level1_2 = Directory.GetDirectoryRoot(path) + path.Split(Path.DirectorySeparatorChar).Skip(1).Take(1).DefaultIfEmpty("").First();

Answer 8

  var di = new System.IO.DirectoryInfo(@"C:\a\b\c");
  Func<DirectoryInfo, DirectoryInfo> root = null;
  root = (info) => info.Parent.FullName.EndsWith("\\") ? info : root(info.Parent);
  var rootName = root(di).Name; //#a

Answer 9

Why not just use System.IO.Path to retrieve the name?

MessageBox.Show(System.IO.Path.GetFileName(
    System.IO.Path.GetDirectoryName(
        System.IO.Path.GetDirectoryName(@"C:\Level1\Level2\Level3")
    )
));

This returns Level 1 .

MessageBox.Show(System.IO.Path.GetFileName(
    System.IO.Path.GetDirectoryName(
        System.IO.Path.GetDirectoryName(@"C:\")
    )
));

This returns empty string.