using System;

using System.IO;

using System.Linq;

using System.Text.RegularExpressions;

​

string[] GetTheFileName(string[] a)

{

    return new [] {

        @"c:\path\to\1109093-A2 (85806S).pdf",

        @"c:\path\to\1109093-A3 (85806S).pdf",

        @"c:\path\to\1109092-A1 (85806S).pdf",

        @"c:\path\to\1109092-A2 (85806S).pdf", 

        @"c:\path\to\1107359 - A02 (2-Pin-Konnektor).pdf",

        @"c:\path\to\1107359-A01 (2-Pin-Konnektor).pdf",

        @"c:\path\to\1107359-A03 (2-Pin-Konnektor).pdf",

        @"c:\path\to\1109042 - A02 (E7927).PDF",

        @"c:\path\to\1109042 - A03 (E7927).pdf",

        @"c:\path\to\1109102 - A01 (85915S hellblau).pdf",

        @"c:\path\to\1109102 - A06 (85915S hellblau).PDF",

    };

}

​

string[] SortFileName(string []TemP)

{

    var paths = GetTheFileName(TemP);

    return paths.Select(x => {

        string filename = Path.GetFileName(x);

        var match = Regex.Match(filename, @"(?<ItemsNumber>\d+)\s*-\s*(?<Revision>\w+)\s+\((?<EndItemNumber>\w.*?)\).[p|P][d|D][f|F]");

        if (match.Success)

        {

            return new { ItemNumber = match.Groups[1].Value, Revision = match.Groups[2].Value, EndItemNumber = match.Groups[3].Value, Path = x };

        }

        else {

            return new { ItemNumber = "", Revision = "", EndItemNumber = "", Path = x };

        }

    })

    .GroupBy(x => x.ItemNumber)

    .Select(x => x.OrderByDescending(y => y.Revision).First())

    .Select(x => x.Path.ToString())

    .ToArray();

}

​

​

var a = new string[0];

foreach (var p in SortFileName(a))

{

    Console.WriteLine(p);

}

​

​