How to correctly order files based on the filename

Question

I use this function:

files = Directory.GetFiles(tbDirectory.Text).ToArray();

and my files saved in this order:

Text.txt
Text_10.txt
Text_2.txt
...
Text_9.txt

I want them to be sorted like windows does:

Text.txt
Text_2.txt
...
Text_9.txt
Text_10.txt

How I can do that?

see this http://stackoverflow.com/questions/34518/natural-sorting-algorithm or http://stackoverflow.com/questions/4389929/how-can-i-use-c-sharp-to-sort-values-numerically. even http://stackoverflow.com/questions/2217029/sort-string-list-with-numeric-values or http://stackoverflow.com/questions/4788227/sorting-a-list-of-strings-numerically-1-2-9-10-instead-of-1-10-2 — nawfal, Jul 03 '13 at 23:58
deleting my answer because I see it does not result in your natural order sort. — John Faulkner, Jul 04 '13 at 00:12

Andrey Shchekin · Answer 1 · 2013-07-04T00:07:57.063

3

If you want to sort them in the same way as Windows, you can use this function for comparison:

[DllImport("shlwapi.dll", CharSet = CharSet.Unicode)]
private static extern int StrCmpLogicalW(string psz1, string psz2);

You then can define your implementation of IComparer<string> that would use this function.

edited Jul 04 '13 at 00:07

answered Jul 03 '13 at 23:57

Andrey Shchekin

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Can you please tell me where to add this code? – biox Jul 04 '13 at 00:05
Normally P/Invoke functions are defined in an internal static class. As for calling it, the best way is to define your own `IComparer`. – Andrey Shchekin Jul 04 '13 at 00:07

score 2 · Accepted Answer · answered Jul 04 '13 at 00:35

2

Based on Andrey Shchekin answer you just need to make a class like this:

internal class FileNameComparer : IComparer<string>
{
    [DllImport("shlwapi.dll", CharSet = CharSet.Unicode)]
    public static extern int StrCmpLogicalW(string psz1, string psz2);

    public int Compare(string a, string b)
    {
        return StrCmpLogicalW(a, b);
    }
}

And then to use this comparer:

files = Directory.GetFiles(tbDirectory.Text).OrderBy(file => file, new FileNameComparer()).ToArray();

answered Jul 04 '13 at 00:35

biox

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All the above duplicates answers will not help beginners in C#, my code is clear and simple for everyone. – biox Jul 04 '13 at 00:37
You've chosen to use your own answer only because it's a copy/paste solution for you. The above answer is the same without providing unneeded information. You've only answered 2 questions, both are your own, and neither was a worthwhile answer. – Dec 02 '13 at 20:15

How to correctly order files based on the filename

2 Answers2