Append to a text file using WriteAllLines

Question

I am using the following code to write in a text file. My problem is that every time the following code is executed it empties the txt file and creates a new one. Is there a way to append to this txt file?

string[] lines = {DateTime.Now.Date.ToShortDateString(),DateTime.Now.TimeOfDay.ToString(), message, type, module };
System.IO.File.WriteAllLines(HttpContext.Current.Server.MapPath("~/logger.txt"), lines);

score 21 · Accepted Answer · edited Apr 01 '15 at 13:57

21

File.AppendAllLines should help you:

string[] lines = {DateTime.Now.Date.ToShortDateString(),DateTime.Now.TimeOfDay.ToString(), message, type, module };
System.IO.File.AppendAllLines(HttpContext.Current.Server.MapPath("~/logger.txt"), lines);

edited Apr 01 '15 at 13:57

Rory McCrossan

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answered Mar 13 '13 at 07:26

Shrivallabh

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AppendAllText does not accept a String Array as the second parameter. The correct answer should be one of those below using the AppendAllLines method. – pierce.jason Mar 27 '15 at 22:44
Just a note, this will not clear existing items in text file. – Kurkula Feb 10 '17 at 20:11

score 9 · Answer 2 · answered Mar 13 '13 at 07:22

9

Use File.AppendAllLines. That should do it

System.IO.File.AppendAllLines(
       HttpContext.Current.Server.MapPath("~/logger.txt"), 
       lines);

answered Mar 13 '13 at 07:22

nunespascal

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score 3 · Answer 3 · answered Mar 13 '13 at 07:38

You could use StreamWriter; if the file exists, it can be either overwritten or appended to. If the file does not exist, this constructor creates a new file.

string[] lines = { DateTime.Now.Date.ToShortDateString(), DateTime.Now.TimeOfDay.ToString(), message, type, module };

using(StreamWriter streamWriter = new StreamWriter(HttpContext.Current.Server.MapPath("~/logger.txt"), true))
{
    streamWriter.WriteLine(lines);
}

score 2 · Answer 4 · answered Mar 13 '13 at 07:26

2

Do something like this :

string[] lines = {DateTime.Now.Date.ToShortDateString(),DateTime.Now.TimeOfDay.ToString(), message, type, module };
          if (!File.Exists(HttpContext.Current.Server.MapPath("~/logger.txt")))
          {
              System.IO.File.WriteAllLines(HttpContext.Current.Server.MapPath("~/logger.txt"), lines);
          }
          else
          {
              System.IO.File.AppendAllLines(HttpContext.Current.Server.MapPath("~/logger.txt"), lines);
          }

So if file is not exists it will create and write in file and if file exists it will append on file.

answered Mar 13 '13 at 07:26

CodeGuru

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5

Not required. AppendAllLines will create the file if it doesn't exist. – nunespascal Mar 13 '13 at 07:28
There is no append lines in System.IO.File – user1292656 Mar 13 '13 at 07:31
@user1292656 : Please check on net AppendAllLines method is there and and you are talking about AppendLines, god knows what it is. – CodeGuru Mar 13 '13 at 08:58

score 1 · Answer 5 · answered Mar 13 '13 at 07:30

1

Use

public static void AppendAllLines( string path, IEnumerable contents )

answered Mar 13 '13 at 07:30

Roman.Potapkin

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3

score 0 · Answer 6 · answered Mar 13 '13 at 07:28

0

three function are available ..File.AppendAllLine ,FileAppendAllText and FileAppendtext..you can try as u like...

answered Mar 13 '13 at 07:28

j.s.banger

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score 0 · Answer 7 · answered Feb 10 '17 at 20:13

0

In all the above cases I prefer to use using to make sure that open and close file options will be taken care of.

answered Feb 10 '17 at 20:13

Kurkula

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Append to a text file using WriteAllLines

7 Answers7

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