How to sort a text file using c#

First, load the text file. Then, create a list of strings by using line breaks as the delimiter. Next, sort the lines using Linq, splitting after the | character. Finally, write the strings to file, putting each on a new line.

string contents = File.ReadAllText(@"D:\Test.tx");
var lines = contents.Split(Environment.NewLine).ToList();
var sorted = lines.OrderBy(l => l.Split("|")[1]).ToList();
// To update the content of the file:
File.WriteAllText(@"D:\Out.tx", string.Join(Environment.NewLine, sorted));

  void SortFile()
        {
            DirectoryInfo d = new DirectoryInfo(@"D:\Test");//Assuming Test is your Folder
            FileInfo[] Files = d.GetFiles("*.txt"); //Getting Text files
            string str = "";
            foreach (FileInfo file in Files)
            {
                int fileNo = Convert.ToInt32(file.Name.Split('|')[1]);
                for (int i = 0; i < Files.Length; i++)
                {
                    if (fileNo < Convert.ToInt32((Files[i].Name.Split('|')[1])))
                    {
                        //Add it to list or something
                    }
                }
            }
        }