Sorting Files By Name same as windows in C#

Question

Possible Duplicate:
Natural Sort Order in C#

i have been looking around for some code to sort my files by name the same as windows,

My dir contains files "SD-Patch-1.sql", "SD-Patch-2.sql" ..., "SD-Patch-10.sql" this is how windows formats them but in my application when sorting by name it sorts them

SD-Patch-1.sql
SD-Patch-10.sql
... to 19
SD-Patch-2.sql

how do I get the same sort as windows to get the above im using

FileInfo[] files = dirInfo.GetFiles();
Array.Sort(files, (f1, f2) => f1.Name.CompareTo(f2.Name));

Who else read this question and thought 'Easy bit of linq should do the job' then got here to find it was more complex? — Lloyd Powell, May 14 '12 at 11:53
http://stackoverflow.com/questions/248603/natural-sort-order-in-c-sharp — Tim Schmelter, May 14 '12 at 11:53
http://stackoverflow.com/questions/1012985/how-would-i-sort-a-list-of-files-by-name-to-match-how-windows-explorer-displays — bjornruysen, May 14 '12 at 11:54
personally i rename my files to have the leading zeros in them, but surely a nifty comparer could do the trick. — ericosg, May 14 '12 at 11:54
http://www.codeproject.com/Articles/11016/Numeric-String-Sort-in-C — Nikhil Agrawal, May 14 '12 at 11:59
is there no way though Linq do i have to all the Windows API to sort them i thought there would be a way though Linq that i jsut could not think off? — HotHeadMartin, May 14 '12 at 12:03
A very simple (but brittle) approach is to do: `var files = dirInfo.EnumerateFiles().OrderBy(x => int.Parse(x.Name.Replace("SD-Patch-", ""))).ToList();` — nawfal, Jun 28 '14 at 19:26

choppy · Answer 1 · 2012-05-15T04:48:19.987

You should use custom comparer in the sort parameter

list.Sort(new customComparer());

the Comparer should look something like this:

class customComparer: IComparer<Object>
{
  public int Compare(Object obj1, Object obj2)
  {
    //implament your own code for sorting any way you want
  }
}

One example of code for your case could be as fallow.

Create dictionary mapping each later to a corresponding number, something like this:

//Mapping between file name characters and their corresponding number of choice
Dictionary<char, int> alphaNumDict = new Dictionary<char, int>()
                                                  {
                                                      {'a',1},
                                                      {'b',2},
                                                      {'c',3},
                                                      {'d',4},
                                                      {'e',5}
                                                      ...
                                                  };

Then you can use a simple method to change string to a number and compare the strings' values:

//iterate over the string and convert it to a corresponding number
double sum =0;
for (int i = 0; i < myString.Length; i++)
{
    sum += alphaDict[myString[i]] * Math.Pow(10, i);
}

Now all you need to do is compare the number you get and return which is bigger

That's obvious thing. He has to create his custom comparer. What matters is what should be written here (`//implement your own code for sorting any way you want`) and what you write. — Nikhil Agrawal, May 14 '12 at 12:06

Sorting Files By Name same as windows in C#

1 Answers1