How to get file names from Directory as it is it exist in C#? [duplicate]

Answer 1

The reason the order is "incorrect" is because the names are strings and therefore are ordered as strings. What you want is to order by the numeric part of it:

DirectoryInfo info = new DirectoryInfo("");
var files = info.GetFiles()
                .OrderBy(p => p.FullName.Split('_')[0])
                .ThenBy(p => int.Parse(p.FullName.Split('_')[1]));

If you are not sure the format is exactly like that (with a _ and then a valid number) then you can:

Func<string, int, int> parseIntOrDefault = (input, defaultValue) =>
{
    int value = defaultValue;
    int.TryParse(input, out value);
    return value;
};

var result = from file in info.GetFiles()
             let sections = file.FullName.Split('_')
             orderby sections[0], sections.Length == 2 ?
                 parseIntOrDefault(sections[1], int.MaxValue) : int.MaxValue
             select file;