Re: Delete line from Excel file - C# Discussion Boards

4-May-09 23:00

Hello.
I'm Reading data from an excel (CSV) file with header row and its fine.
Now I have a file with one more line in the start (above the header) and it giving me a lot of problems.

is there a way from C# to open the csv file and remove the first line?

If not as excel then maybe I'll just open it as a text file and remove it (I know whats the string I want to remove).

Whats the fasted way to remove a string from the beggining of a txt file?

Thanks.

Christian Graus4-May-09 23:05

4-May-09 23:05

polycom123 wrote:
is there a way from C# to open the csv file and remove the first line?

Easy. File.ReadAllLines, to get an array of strings, then write the file over itself, skipping the lines you don't want anymore

Christian Graus

Driven to the arms of OSX by Vista.

"I am new to programming world. I have been learning c# for about past four weeks. I am quite acquainted with the fundamentals of c#. Now I have to work on a project which converts given flat files to XML using the XML serialization method" - SK64 ( but the forums have stuff like this posted every day )

OriginalGriff4-May-09 23:34

OriginalGriff

4-May-09 23:34

Or better, write it into a new file, so it doesn't mess up Excel and other users?

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polycom1235-May-09 0:15

5-May-09 0:15

I can't do that since I need to countinu working on the same file with others.

Taht another thinh I was afried of, that if I'll read and write it will mass up my original file Frown | :(

Thats why I hoped that C# will have a built in function for this.

Thanks for your reply.

polycom1235-May-09 0:11

5-May-09 0:11

Hi christian,
Thakns for the replay.

I was hopping that C# have a built in function to work with excel and do this instead of me having to read a file with a lot of data (about 7,000 line with 10 column each).

But like I was afried, I might have no other choise other that read the whole file and write it back.

Thanks.

Philipp Sumi4-May-09 23:32

Philipp Sumi

4-May-09 23:32

You will have to rewrite the whole file if you want to change it's contents. You should find quite a few samples through Google (e.g. http://stackoverflow.com/questions/532217/efficient-way-to-delete-a-line-from-a-text-file-c[^]).

Regarding CSV: There's a few frameworks flying around that provide you with an abstract view of a CSV file (there's even a LINQ implementation here on CodeProject). And of course, just retaining the file and ignoring the line in question might be an alternative, too. However, the added functionality most likely comes with a price regarding performance.

Cheers,
Philipp

NetDrives - Open Source Network Share Management

The solution

polycom1235-May-09 2:11

5-May-09 2:11

Hello all,

Thanks for the replies.

As you mantioned - I can not realy delete the first line so what I did at the end was to read the file (file.readAllLines(), As I saw in the answers) and then create it again after discarding the first line.

Not very elegant but work Smile | :)

Thanks again!

roy.

Re: The solution

dan!sh 5-May-09 2:44

dan!sh

5-May-09 2:44

Your question says you need to read the file. If that is the case, File.ReadAllLines alone should work. Just remove the first line from the array for further processing.

जय हिंद

Re: The solution

Dave Kreskowiak5-May-09 4:43

Dave Kreskowiak

5-May-09 4:43

For removing lines from a text file, the solution you used is as elegant as your going to get.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007, 2008

Array

mostafatajamolian4-May-09 22:57

mostafatajamolian

4-May-09 22:57

Hi i have a file pdf for to explan dar moprede parametrhaye Array

exampel:
int[] a1=new int[2] {1,2};

a1.{parametr}

pleas

Rose | [Rose]

Re: Array

Christian Graus4-May-09 23:04

reading reodonly files for backup (Steams)

4-May-09 23:04

I"m sorry, but you'll have to ask in English, I have no idea what you're asking. However, if you want to parse a PDF, you need a PDF library for that.

Re: Array

musefan4-May-09 23:25

musefan

4-May-09 23:25

int param1 = a1[0];
int param2 = a1[1];

if that's not what you wanted to know then you need to specify more clearly.

Life goes very fast. Tomorrow, today is already yesterday.

fracalifa4-May-09 22:55

fracalifa

4-May-09 22:55

Hi all,

I have to backup some files, some with readonly attrib.
Is there an other way to open the files with readonly attribute than to reset the "r" attribute, reading and re-setting the attribute again ?

tnx
Frank

Christian Graus4-May-09 23:06

4-May-09 23:06

Yes, write code that only asks for read access, then you won't have any problems. I believe I found recently that some .NET libraries ask for full access even if you ask for read only, so I would try using a different class to do what you want, or just use File.Copy to copy the file to the new location.

fracalifa4-May-09 23:10

fracalifa

4-May-09 23:10

Thank you,

no can't use copy due to store the files in a database ...

Frank

Christian Graus4-May-09 23:15

4-May-09 23:15

Oh, I didn't get they were going into a DB. Well, then change the code you use to read the file. I think File.ReadAllBytes works fine, but using streams does not work, from memory. It's a bug in the framework, essentially.

File path problem (Path contains a space)

Luc Pattyn4-May-09 23:31

Luc Pattyn

4-May-09 23:31

Christian Graus wrote:
using streams does not work ... It's a bug in the framework, essentially.

I disagree. Creating a Stream from a path, without specifying the intended access, assumes read/write intentions. What else should the framework do?

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Avoiding unwanted divs (as in "articles needing approval") with the help of this FireFox add-in

bonkers1234-May-09 22:35

bonkers123

4-May-09 22:35

Hi, I am trying to start an application from my application, which opens a default file, given it's arguments as follow:

Process prc = new Process();
        prc.StartInfo.FileName = "azman.msc";
        prc.StartInfo.Arguments = "msxml://" + Environment.CurrentDirectory + "\\AuthorizationStore.xml"; // CurrentDirectory = C:\Users\Hugo\Documents\Visual Studio 2008\Projects\AzManTest\AzManTest\bin
        prc.Start();

Note the current curectory is:
CurrentDirectory = C:\Users\Hugo\Documents\Visual Studio 2008\Projects\AzManTest\AzManTest\bin
Which contains spaces. For some or other odd reason, it does not like this ...
If this directory is in such a location that there are no spaces in the Directory name, then this works fine...

Can I replace the spaces of the directory with something ? How can I fix this problem.
Any help would be much appreciated!

Re: File path problem (Path contains a space)

Christian Graus4-May-09 22:44

Re: File path problem (Path contains a space)

4-May-09 22:44

It's not odd, the space is used as a delimiter for arguments. Put the path in quotes to get around this.

bonkers1234-May-09 23:15

bonkers123

4-May-09 23:15

LOL .... thanks ^_^

prc.StartInfo.Arguments = "msxml://" + "\"" + Environment.CurrentDirectory + "\\AuthorizationStore.xml" + "\"";

Is this the way to escape a " character?

Re: File path problem (Path contains a space)

Christian Graus4-May-09 23:20