写入排序的文本文件

Question

I am unsure of what I am doing wrong here. It compiles and runs, and acts ok, but it is not writing the line into the text file. I have my FileStream and read on MSDN to try and figure this out on my own. When I did get something to work, it overwrote the entire file with what I put into it. So I am hoping maybe a programmer who has done this for more than 4 months (such as me) can explain. Here is a piece of my code that I think is relevant.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;

namespace ConsoleApplication33
{
class Program
{
    static void Main(string[] args)
    {
        FileStream FireBall = new FileStream("Students.txt", FileMode.Open, FileAccess.Read);
        StreamReader inFile = new StreamReader(FireBall);
        string inValue;
        string[] values;
        double GPA;
        double total = 0;
        double counter = 0;
        double count = 0;
        double counti = 0;
        double counterr = 0;
        List<string> Anderson = new List<string>(); //Anderson
        List<string> gpa = new List<string>(); //GPA
        List<string> noemail = new List<string>(); // email
        List<string> lines = new List<string>();


        string newLastName = "'Constant";
        string newRecord = "(LIST (LIST 'Constant 'Malachi 'D ) '1234567890 'mdconstant@mail.usi.edu 4.000000 )";
        string line;
        string lastName;
        bool insertionPointFound = false;

        for (int i = 0; i < lines.Count && !insertionPointFound; i++)
        {

            line = lines[i];
            if (line.StartsWith("(LIST (LIST "))
            {
                values = line.Split(" ".ToCharArray());
                lastName = values[2];
                if (newLastName.CompareTo(lastName) < 0)
                {
                    lines.Insert(i, newRecord);
                    insertionPointFound = true;
                }
            }
        }
        if (!insertionPointFound)
        {

            lines.Add(newRecord);
        } 

Answer 1

You don't do any writing here. Note that you are using FileAccess.Read in

FileStream FireBall = new FileStream("Students.txt", FileMode.Open, FileAccess.Read);

It should be replaced with FileAccess.ReadWrite

You can use StreamWrite to write to the file. And you can read and write easily with File.ReadAllText and File.WriteAllText

Answer 2

What I don't see is any code that writes to the file itself. If you are reading the contents of the file into the lines List , writing to that list is not the same as writing to the actual file.

So you need to explicitly write to the file, with something like a StreamWriter . See here: http://msdn.microsoft.com/en-us/library/6ka1wd3w.aspx