How to write text file with fixed length in C#

Question

1.00/5 (1 vote)

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i need to write data to file in specified position with fixed length for each column with start position,end position and length of column. could you please alter my code or suggest.I have given sample length for each column

C#

Column	startposition  endposotion  Length
     1		1	        9	         9	
     2		10	       20	         10
     3		21          29           8
     4      30          31           1
     5		32	        42          10

Output i needed to write in text file as:

C#

00000	  2014-09-23 01:36:22 F	2014-09-23
000000	  2014-09-23 01:36:22 F	2014-09-23
000000000 2014-09-23 01:36:22 F	2014-09-23

below is code which i have created

string txt = string.Empty;
DataTable employeeTable = new DataTable("Employee");
employeeTable.Rows.Add("00000", "2014-09-23", "01:36:22", "F", "2014-09-23");
employeeTable.Rows.Add("000000", "2014-09-23", "01:36:22", "F", "2014-09-23");
employeeTable.Rows.Add("000000000", "2014-09-23", "01:36:22", "F", "2014-09-23");
DataSet ds = new DataSet("Organization");
ds.Tables.Add(employeeTable);
string filepath = Application.StartupPath + "\\" + "file.txt" ;
StreamWriter sw = null;
sw = new StreamWriter(filepath, false);
foreach (DataRow row in ds.Tables[0].Rows)
{
foreach (var item in row.ItemArray)
{
//Add the Data rows.
txt += item.ToString() + "\t";
}
txt += "\r\n";
}
sw.Write(txt);
sw.Close();

OutPut which iam getting from this code is, but this is wrong.

C#

00000	2014-09-23	01:36:22	F	2014-09-23	
000000	2014-09-23	01:36:22	F	2014-09-23	
000000000	2014-09-23	01:36:22	F	2014-09-23

kindly rectify my problem.

What I have tried:

string txt = string.Empty;
DataTable employeeTable = new DataTable("Employee");
employeeTable.Rows.Add("00000", "2014-09-23", "01:36:22", "Falseis1", "2014-09-23", "01:36:22");
employeeTable.Rows.Add("000000", "2014-09-23", "01:36:22", "F", "2014-09-23", "01:36:22");
employeeTable.Rows.Add("000000000", "2014-09-23", "01:36:22", "F", "2014-09-23", "01:36:22");
DataSet ds = new DataSet("Organization");
ds.Tables.Add(employeeTable);
string filepath = Application.StartupPath + "\\" + "file.txt" ;
StreamWriter sw = null;
sw = new StreamWriter(filepath, false);
foreach (DataRow row in ds.Tables[0].Rows)
{
foreach (var item in row.ItemArray)
{
//Add the Data rows.
txt += item.ToString() + "\t";
}
txt += "\r\n";
}
sw.Write(txt);
sw.Close();

Posted 30-Nov-17 20:19pm

Vinodh Muthusamy

Updated 28-Oct-19 5:04am

v10

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Comments

Sinisa Hajnal 1-Dec-17 2:53am

Since your columns are of different lengths, you cannot use tab as separator (fixed length separator). Instead, determine the longest text in each column and set that + 1 space (or whatever number of spaces fits your case). You need to pad all other strings to that max length + spaces and then concatenate them.

Vinodh Muthusamy 1-Dec-17 3:47am

couldyou please modify my code

Richard MacCutchan 1-Dec-17 4:24am

It should be obvious that you need to create each text item in a fixed width field. string.Format will help you do that.

3 solutions

Solution 2

Don't use string concatenation in a loop! You've already got a StreamWriter which you can use to write each part of the string to.

And the simplest option for fixed-width output is to use the alignment option of the string formatting feature:
Composite Formatting | Microsoft Docs[^]

C#

using (StreamWriter sw = new StreamWriter(filepath, false))
{
    foreach (DataRow in ds.Tables[0].Rows)
    {
        writer.WriteLine("{0,-9}{1,-10}{2,-8}{3}{4,-10}", row.ItemArray);
    }
}

Output:

00000    2014-09-2301:36:22F2014-09-23
000000   2014-09-2301:36:22F2014-09-23
0000000002014-09-2301:36:22F2014-09-23

Posted 1-Dec-17 7:17am

Richard Deeming

Comments

Vinodh Muthusamy 5-Dec-17 2:50am

thanks Richard, it sounds good.its working

Member 13968331 31-Aug-18 4:03am

what am I going to do in order for the output to be aligned specially the sign(*) since when I outputted it it is not align and how to make that program in which i will update a certain line

Solution 4

You can use the AGPC.FixedLayout Nuget to do it in a simply way

Posted 28-Oct-19 5:04am

alexandregpc

Comments

CHill60 29-Oct-19 9:36am

Beware - this could be perceived as site driving

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OriginalGriff · Accepted Answer · 2017-11-30T22:03:00

Solution 1

After you have converted an object to a string, you can use the PadLeft and PadRight methods to justify them into a fixed length string:

C#

object o1 = "0000";
object o2 = "00000";
Console.WriteLine("\"" + o1.ToString().PadLeft(8) + "\"");
Console.WriteLine("\"" + o2.ToString().PadRight(8) + "\"");

Will give you:

"    0000"
"00000   "

You can use this on each field to give you the fixed widths you need.

Posted 30-Nov-17 22:03pm

OriginalGriff

Comments

Vinodh Muthusamy 1-Dec-17 4:33am

But i need to start with specified start position of each columns

OriginalGriff 1-Dec-17 4:54am

And if you start at the beginning of the record, and pad each field to the right length as you write them, that is what you will get...