how to update a single line of text file

[kashif73]

i have a text file which has a fixed length lines. How can I update a particular line (record ) basing on a record ID provided? below is my code which retrieves a particular line from the textfile & display it in xtboxes in my update form.:

If System.IO.File.Exists(FILE_NAME) = True Then
Dim fs As New FileStream(FILE_NAME, FileMode.Open, FileAccess.Read)
Dim sr As New StreamReader(fs)
Dim Contents As String = sr.ReadToEnd()
Dim strSearch As String = "^(.*?)" & Quest.Text & ""
Dim myRegex As New Regex(strSearch, RegexOptions.Multiline)
If myRegex.IsMatch(Contents) Then
Dim myMatch As Match = myRegex.Match(Contents)
Dim theFoundLine As String = myMatch.Groups(0).Value
'Display the found line
 
Dim splitText() As String = theFoundLine.Split(";")
OS01Rec.Text = splitText(0).Trim
os01a.Text = splitText(1).Trim
OS01b.Text = splitText(2).Trim
OS01c.Text = splitText(3).Trim
...................... so on

so basically this array holds each field in its respective textbox. Now how to overwrite the textfile???any idea?
Thanks.

[Curtis Rutland]

Basically you should do the same thing that you did reading from it, but using StreamWriter instead of StreamReader.

First of all, make sure you close all open streams when you are done with them, so close your FileStream and StreamReader objects (you should do this as soon as you are done reading from them). When you want to write, create the FileStream again, except with Write permissions instead of Read. Then, make a StreamWriter with that FileStream. Then, use the StreamWriter to write to the file.
Example

FileStream fs = new FileStream(@"c:\dev\test.txt",FileMode.Open, FileMode.Write);
StreamWriter sw = new StreamWriter(fs);
sw.WriteLine("Whatever I want to write to the file.");
sw.Close();
fs.Close();
 

[kashif73]

Example

FileStream fs = new FileStream(@"c:\dev\test.txt",FileMode.Open, FileMode.Write);
StreamWriter sw = new StreamWriter(fs);
sw.WriteLine("Whatever I want to write to the file.");
sw.Close();
fs.Close();
 

[/quote]

Thanks for your reply InsertAlias.
But I want only that particular line of my text file to be updated,which was called in the form for updation.This code is overwriting the first line of my text file.It doesnot update that particular ID record . I mean i am getting duplicate lines in my text file (with same ID numbers). Please see below the actual sample of text file:

4;dhl;khush;delivered;22;33;44urban;kashif;malik;r ehman;;;good;n;;1;2;3;;5;6;7;8;;0;11;22;33;;55;004
3;;multiple;No;done;22;33;44urban;kashif;malik;reh man;Y;N;good;n;;1;2;3;4;5;6;7;22;22;2;003
2;;multiple;No;done;22;33;44urban;kashif;malik;reh man;Y;N;good;n;;1;2;3;4;5;6;7;22;22;2;002

The last record is the ID against which we select that line for updation. so only that ID should be updated not others.
Any thoughts? Would be grateful foryour reply.Thanks.

[kashif73]

Anyone please. I have to solve this urgently. Thanks in advance for your help.

[Curtis Rutland]

Well, the way I would solve the problem is to overwrite the whole text file. I'd re-write the things that didn't change as well as what did.

That's one of the problems with using text files instead of databases...less flexibility.

[kashif73]

Well, the way I would solve the problem is to overwrite the whole text file. I'd re-write the things that didn't change as well as what did.

That's one of the problems with using text files instead of databases...less flexibility.

Boss, How to overwrite the whole file? can you please help me with some code. Thanks.