C# Output text to file on a new line

Question

I have some code which outputs data from the FileSystemWatcher class, although each times to outputs a line to test.txt, it overwrites the previous entry, is there a way to stop this happening?

Code in question:

static void FileWatcher_Created(object sender, FileSystemEventArgs e)
{

    using (StreamWriter fileWriter = new StreamWriter("test3.txt"))
    {
        var data = true;
        fileWriter.Write("C:\\" + e.Name + Environment.NewLine);
    }

Full Code:

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

namespace FileWatcherr
{
class Program
{    
    static void Main(string[] args)
    {
        string dirPath = "C:\\";
        FileSystemWatcher fileWatcher = new FileSystemWatcher(dirPath); 
        fileWatcher.IncludeSubdirectories = true;  
        fileWatcher.Filter = "*.exe";    
        // fileWatcher.Filter = "C:\\$Recycle.Bin";   
        //  fileWatcher.Changed += new FileSystemEventHandler(FileWatcher_Changed);   
        fileWatcher.Created += new FileSystemEventHandler(FileWatcher_Created);    
        //  fileWatcher.Deleted += new FileSystemEventHandler(FileWatcher_Deleted);  
        //  fileWatcher.Renamed += new RenamedEventHandler(FileWatcher_Renamed);    
        fileWatcher.EnableRaisingEvents = true;      

        // updated code


        Console.ReadKey(); 
    }



        static void FileWatcher_Renamed(object sender, RenamedEventArgs e)
        {
            Console.WriteLine(e.OldName + " was renamed to " + e.Name);
        }

        static void FileWatcher_Deleted(object sender, FileSystemEventArgs e)

        {
            Console.WriteLine(e.Name + " was deleted");
        }

        static void FileWatcher_Created(object sender, FileSystemEventArgs e)
        {

            using (StreamWriter fileWriter = new StreamWriter("test3.txt"))
            {
                var data = true;
                fileWriter.Write("C:\\" + e.Name + Environment.NewLine);
            }

        }

        static void FileWatcher_Changed(object sender, FileSystemEventArgs e)
        {
            Console.WriteLine(e.Name + "");
        }
    }
}

As lots of people have suggested the same thing, you can assume that it is correct. Something else is a problem for you, so please add info of your new problem — Oskar Kjellin
– Oskar Kjellin, Commented May 20, 2011 at 19:44

Oskar Kjellin · Accepted Answer · 2011-05-20 19:49:08Z

3

Edit your code to be the below. The second parameter to the StreamWriter is if we should append or overwrite. Set to true to append and false to overwrite (default, thus your problem)

   using (StreamWriter fileWriter = new StreamWriter("test3.txt", true))
    {
        var data = true;
        fileWriter.WriteLine(Path.Combine("C:\\", e.Name));
    }

More info about this constructor can be found here http://msdn.microsoft.com/en-us/library/36b035cb.aspx

edited May 20, 2011 at 19:49

answered May 20, 2011 at 19:40

Oskar Kjellin

22k10 gold badges57 silver badges95 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Oskar Kjellin Over a year ago

@Michael what is the problem? I found a syntax error I fixed, try the current code

Bala R · Accepted Answer · 2011-05-20 19:40:58Z

0

Try

using (StreamWriter fileWriter = new StreamWriter("test3.txt", true))
{
...
}

answered May 20, 2011 at 19:40

Bala R

109k23 gold badges203 silver badges212 bronze badges

Comments

Adriano Carneiro · Accepted Answer · 2011-05-20 19:41:31Z

0

Replace

new StreamWriter("test3.txt")

by

new StreamWriter("test3.txt", true)

This will make the stream append to the file.

answered May 20, 2011 at 19:41

Adriano Carneiro

58.8k12 gold badges94 silver badges123 bronze badges

Comments

Alireza Maddah · Accepted Answer · 2011-05-20 19:45:12Z

0

Consider opening file to append:

    using (StreamWriter fileWriter = new StreamWriter("test3.txt", true))
    {
        var data = true;
        fileWriter.WriteLine("C:\\" + e.Name);
    }

Note that it is better to use WriteLine method.

edited May 20, 2011 at 19:45

answered May 20, 2011 at 19:40

Alireza Maddah

5,9252 gold badges23 silver badges29 bronze badges

2 Comments

Dariusz Tarczynski Over a year ago

Use string.format or with Concat function instead of concatenating strings your way

Oskar Kjellin Over a year ago

@dario Even though it is correct that you should not just add together strings, combining paths is usually recommended to be done with Path.Combine

Felix Martinez · Accepted Answer · 2011-05-20 19:47:38Z

0

The StreamWriter class has an overload constructor that takes a second bool parameter which specifies if you want to append to an existing file. More information here.

answered May 20, 2011 at 19:47

Felix Martinez

3,9783 gold badges33 silver badges32 bronze badges

Collectives™ on Stack Overflow

C# Output text to file on a new line

5 Answers 5

1 Comment

Comments

Comments

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

1 Comment

Comments

Comments

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related