Reading specific line in file

Question

0.00/5 (No votes)

See more:

Hi,
How to read one line from file? When I want to write to file its simply I just create FileStream and FileWriter and write line. But what if I want to read some specific line? I've noticed that FileReader exists too but didn't found nowhere how to use it.
I'am sorry for such noob question I'am learning C# just few days. Thanks for any help.

EDIT: Well so it should look like str = streamReader.ReadLine(); but how can I specify what line I want to read? Can't find how to use ReadLine and msdn explanation is bad :(

Posted 14-Feb-12 9:13am

LosEagle

Updated 14-Feb-12 10:51am

v4

Add a Solution

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Dr.Walt Fair, PE · Accepted Answer · 2012-02-14T11:02:00

Solution 2

Reading lines from a file is a linear, forward only process. In other words, if you want to read line number N, you read lines 1 through N-1 (and throw them away if you don't need them) and then the next line read will be line N.

Posted 14-Feb-12 11:02am

Dr.Walt Fair, PE

Sergey Alexandrovich Kryukov · Accepted Answer · 2012-02-14T09:17:00

Solution 1

For line-oriented reading from file/stream, use System.IO.StreamReader:
http://msdn.microsoft.com/en-us/library/system.io.streamreader.aspx[^].

—SA

Posted 14-Feb-12 9:17am

Sergey Alexandrovich Kryukov

Comments

LosEagle 14-Feb-12 15:24pm

Thanks :) so it should look like string str = streamReader.ReadLine(); but I can't find how to specify what line to read when I type something into brackets it shows error :-/

Dave Kreskowiak 14-Feb-12 20:53pm

You can't find the method to do it because it doesn't exist. Since a "line" can be any length, it's impossible to predict where in the file your specified line is going to be.

You have to ReadLine the entire file, counting them along the way, until you get to the specified line you want. If the file is small enough, you can just read the entire file into a String() using ReadAllLines and then you don't need the file anymore. You can just quickly get the line you want from the array of Strings.

Sergey Alexandrovich Kryukov 15-Feb-12 11:00am

Exactly. One can know the line boundaries only after reading all of them as they have different lengths. Thanks for your help, Dave.
--SA

LosEagle 15-Feb-12 9:22am

Ok thanks :) I think I know what you mean

Sergey Alexandrovich Kryukov 15-Feb-12 11:00am

You are welcome.
Good luck, call again.
--SA