textwriter.close deletes my data

hey,

i got this weird problem.
i am making a little textediting program and somehow when i have written a txt file and close it via:

tc.Close();

the text file goes blank. nothing left.

the code ( sorry if it looks like rubbish. i just started programming in C#) :

Code:

---

static void opentxtfile(string input)
        {
            Console.Clear();
            if (input == " ")
            {
                Console.WriteLine("TEXTEDITOR \n \nGive the name of the text file, or 1 to exit\n\n");
                Console.Write("file:  ");
                string input2 = Console.ReadLine();
                Thread.Sleep(1);
                if (input2 == "1" )
                {
                    txtedit();
                    return;
                }
                else
                opentxtfile(input2);
                return;
            }
            else
            Thread.Sleep(1);
            if (!File.Exists(MAINDIR + "\\documents\\text\\" + input + ".txt"))
            {
                Console.WriteLine("text file does not exist.");
                txtedit();
                return;
            }
            TextReader tw = new StreamReader(MAINDIR + "\\documents\\text\\" + input + ".txt");
            Int32 NumberOfLines = 1;
           


         
            Thread.Sleep(1);
            using (StreamReader r = new StreamReader(MAINDIR + "\\documents\\text\\" + input + ".txt"))
            {
                int i = 0;
                while (r.ReadLine() != null) { i++; }
                NumberOfLines = i + 1;
               
            }
         
            string[] ListLines = new string[NumberOfLines+1];
            for (int i = 1; i < NumberOfLines; i++)
            {
                ListLines[i] = tw.ReadLine();
            }
           
            Console.Clear();
            for (int y = 1; y < NumberOfLines; y++)
            {
                Console.WriteLine(ListLines[y]);
            }
            tw.Close();
            Thread.Sleep(1);
            string newline = Console.ReadLine();

            TextWriter tc = new StreamWriter (MAINDIR + "\\documents\\text\\" + input + ".txt");

            if (newline != "/quit")
            {

                Thread.Sleep(5);
                int a;
                for (a = 1; a < NumberOfLines; a++)
                {
                    tc.WriteLine(ListLines[a]);
                }
                Thread.Sleep(5);
                ListLines[NumberOfLines] = newline;
                tc.WriteLine(ListLines[NumberOfLines]);
                tc.Close();
                Thread.Sleep(5);
                opentxtfile(input);
                return;
            }
            else
            tc.Close(); //  right here
            Thread.Sleep(500);
            txtedit();
            return;
           
        }

---

Hi there. It's difficult to fully understand the purpose of your program because the txtedit() function is missing, but I am guessing you want to:

• get a valid filename
• read that file
• output the contents to the console
• allow the user to enter additional lines of text which will be appended to the end of the file.
• stop adding new lines when they type /quit

Since you've clearly made an effort to do this for yourself, I don't see the harm in offering you another perspective on solving this task. So assuming I've correctly identified the requirements for your program, this is what I'd do:

Code:

---

static void Main(string[] args)
{
    String filename = String.Empty;

    while (true) // find a file
    {
        Console.Write("enter filename: ");
        filename = Console.ReadLine();

        if (File.Exists(filename))
            break; // filename is valid, let's move on
        else Console.WriteLine("file not found");
    }

    using (StreamReader reader = File.OpenText(filename)) // open the file
        while (!reader.EndOfStream) // read to the end of the file
            Console.WriteLine(reader.ReadLine()); // print the next line from the file

    using (StreamWriter writer = File.AppendText(filename)) // write to the file
    {
        while (true)
        {
            String str = Console.ReadLine();

            if (str == "/quit")
                break; // we are done adding more

            writer.WriteLine(str); // add next line to the file
        }
    }
}

---

I'm not entirely sure why your version didn't work. Maybe it's because you have a TextReader and a StreamReader open to the file at the same time. (By the way, you don't appear to use the TextReader at all.) Maybe TextWriters don't allow appending. I've never used them before. Perhaps that is something you could investigate.

Hope this helps.

Quote:

---

Originally Posted by theoobe

Maybe it's because you have a TextReader and a StreamReader open to the file at the same time.

---

According to the msdn (TextWriter Class (System.IO)) TextWriter is not thread safe, and I see in his example that he's got Thread() stuff happening. I don't know enough C# to follow everything happening here, but it's a point to check on maybe.


Quzah.