Main function looping based on file called in a different class

Question

Rookie here so please be nice!! I have had so much fun learning to program and gotten some great help along the way when google failed me. But alas, I'm stuck again.

I have a C# program that looks like this (It's MWS if anyone is familiar)

I've tried so many different ways to get this to effectively loop through a list of values in a text file. The problem I'm having is that the Main function is where I have to set the loop, but the BuildClass is where I need to cycle through the values in the text file (sentinel). I've included some stuff that probably isn't necessary just in case it is messing my code up and I don't realize it.

• Here's what I've tried:

  1. setting the loop inside the BuildClass - didn't expect it to work but it threw an exception before getting to the sentinel.
  2. Reference the sentinel within the main function by changing the "using" or "var" in the main function sentinel to public - turned EVERYTHING red in visual studio
  3. moving the string sentinel outside the main function so that the function and the BuildClass would recognize it - main function did not recognize it anymore.
  4. I've tried so many other things unsuccessfully. I've gotten it to loop with the same sentinel value passed from BuildClass to the function over and over again but that's about it.

• What I think I need:

  1. A destructive version of streamReader that will remove the value from the text file when reading it. I'll put this inside the BuildClass, so that the next loop of the main function, the next value will be read and passed into the main function until the file is empty, terminating the loop.
  2. an understanding of why changing sentinel to public destroys the code so badly. I have a decent understanding of why the other attempts wouldn't work.

---

namespace MainSpace
{
    public class MainClass
    {
        int i;
        public static void Main(string[] args)
        {         
            ClientClass client = new ClientInterface(appName, appVersion, password, config);

            MainClass sample = new MainClass(client);
            string sentinel;
            using (var streamReader = new StreamReader(@"sample.txt", true))
                while((sentinel = streamReader.ReadLine()) != null)
                {
                    try
                    {
                    //stuff
                    response = sample.InvokeBuild();
                    Console.WriteLine("Response Stuff");
                    string responseXml = response.ToXML();
                    Console.WriteLine(responseXml);
                    StreamWriter FileWrite = new StreamWriter("FileTest.xml", true);
                    FileWrite.WriteLine(responseXml);
                    FileWrite.Close();
                }
                catch (ExceptionsClass)
                {
                    // Exception stuff
                    throw ex;
                }

                }
        }
        private readonly ClientInterface client;

        public MainClass(ClientInterface client)
        {
            this.client = client;
        }

        public BuildClass InvokeBuild()
        {
            {
                using (var streamReader = new StreamReader("sample.txt", true))
                {
                    string sentinel = streamReader.ReadLine();
                    Thread.Sleep(6000);
                    i++;
                    Console.WriteLine("attempt " + i);
                    // Create a request.
            RequestClass request = new RequestClass();
            //Password Stuff 
            request.IdType = idType;
            IdListType idList = new IdListType();
            idList.Id.Add(sentinel);
            request.IdList = idList;
            return this.client.RequestClass(request);
            }

            }
        }



    }