Creating a fixed width file in C#

Question

What is the best way to create a fixed width file in C#. I have a bunch of fields with lengths to write out. Say 20,80.10,2 etc all left aligned. Is there an easy way to do

Answer 1

The various padding/formatting posts prior will work sufficiently enough, but you may be interested in implementing ISerializable.

Here's an msdn article about Object Serialization in .NET

Answer 2

Try FileHelpers: www.filehelpers.com

Here's an example: http://www.filehelpers.com/quick_start_fixed.html

Answer 3

You can use http://www.filehelpers.com/

Answer 4

use String.Format()

http://msdn.microsoft.com/en-us/library/aa331875.aspx

Answer 5

Use the .PadRight function (for left aligned data) of the String class. So:

handle.WriteLine(s20.PadRight(20));
handle.WriteLine(s80.PadRight(80));
handle.WriteLine(s10.PadRight(10));
handle.WriteLine(s2.PadRight(2));

Answer 6

I am using an extension method on string, yes the XML commenting may seem OTT for this, but if you want other devs to re-use...

public static class StringExtensions
{

    /// <summary>
    /// FixedWidth string extension method.  Trims spaces, then pads right.
    /// </summary>
    /// <param name="self">extension method target</param>
    /// <param name="totalLength">The length of the string to return (including 'spaceOnRight')</param>
    /// <param name="spaceOnRight">The number of spaces required to the right of the content.</param>
    /// <returns>a new string</returns>
    /// <example>
    /// This example calls the extension method 3 times to construct a string with 3 fixed width fields of 20 characters, 
    /// 2 of which are reserved for empty spacing on the right side.
    /// <code>
    ///const int colWidth = 20;
    ///const int spaceRight = 2;
    ///string headerLine = string.Format(
    ///    "{0}{1}{2}",
    ///    "Title".FixedWidth(colWidth, spaceRight),
    ///    "Quantity".FixedWidth(colWidth, spaceRight),
    ///    "Total".FixedWidth(colWidth, spaceRight));
    /// </code>
    /// </example>
    public static string FixedWidth(this string self, int totalLength, int spaceOnRight)
    {
        if (totalLength < spaceOnRight) spaceOnRight = 1; // handle silly use.

        string s = self.Trim();

        if (s.Length > (totalLength - spaceOnRight))
        {
            s = s.Substring(0, totalLength - spaceOnRight);
        }

        return s.PadRight(totalLength);
    }
}