formatting date time

Question

2.00/5 (1 vote)

See more:

I am having trouble formatting a datetime to use as part of a file name. I am needing it to look like this: yyyy/dd/mm hh:mm:ss. I keep getting the error that the file path could not be found. I searched the forum and found an example that looked like mine but it did not help when I implemented it. Thank you for your help.

C#

DateTime date = DateTime.Now;
                    string dateNow = date.ToString();
                    string saveTime = String.Format("s = {0:s}", dateNow);
                    saveTime.Replace('/', '-').Replace(':', '-');

                    try
                    {
                        OleDbDataReader dr1 = cmd.ExecuteReader();
                        StreamWriter sw = new StreamWriter(@"C:\travelersTEST\travelersExport" + saveTime + ".csv");
                        if (dr1.HasRows)
                        {
                            dt.Load(dr1);
                            dt.AcceptChanges();
                        }
                        // Now write all the rows.

                        sw.Write("Policy Number, Effective Date, Transaction Premium, Comm Rate, Comm Due");
                        sw.Write(sw.NewLine);
                        
                            foreach (DataRow dr in dt.Rows)
                            {
                                if (dr[0].ToString() != "")
                                {
                                    sw.Write(dr[0].ToString() + ",");
                                    sw.Write(dr[1].ToString() + ",");
                                    sw.Write(dr[2].ToString() + ",");
                                    sw.Write(dr[3].ToString() + ",");
                                    sw.Write(dr[4].ToString());
                                    sw.Write(sw.NewLine);
                                }
                                
                            }
                        sw.Close();
                    }
<pre lang="cs">catch (OleDbException caught)
                    {
                        Response.Write(caught.Message);
                    }
                    finally
                    {
                        conn.Close();
                    }

                    string fileName = ("travelersExport" + saveTime + ".csv");
                    string filePath = (@"C:\travelersTEST\travelersExport" + saveTime + ".csv");

                    Response.Clear();
                    Response.AppendHeader("content-disposition",
                    "attachment; filename=" + fileName);
                    Response.ContentType = "application/octet-stream";
                    Response.WriteFile(filePath);
                    Response.Flush();
                    Response.End();
                }
            }
            else
            {
                Response.Write("This file does not exist.");
            }
        }

Posted 30-May-12 9:45am

Richard C Bishop

Updated 30-May-12 10:08am

Maciej Los

v3

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)

OriginalGriff · Accepted Answer · 2012-05-30T09:49:00

Solution 1

You can't put '/' or '\' characters in file names as you have found - so use the '-' instead.
You don't have to play with it at all - DateTime.ToSting has an overload that takes a format specification, which will allow you to generate the name directly:

C#

string dateString = DateTime.Now.ToString("yyyy-MM-dd");

Have a look here: Formatting a DateTime for display - format string description[^]

Posted 30-May-12 9:49am

OriginalGriff

Comments

Maciej Los 30-May-12 16:09pm

Good answer, my 5!

Richard C Bishop 30-May-12 17:33pm

So much easier, thank you!

OriginalGriff 31-May-12 3:34am

You're welcome!

Espen Harlinn 31-May-12 15:20pm

5'ed!

Sergey Alexandrovich Kryukov · Accepted Answer · 2012-05-30T09:54:00

Please see:
http://msdn.microsoft.com/en-us/library/system.datetime.aspx[^].

Pay attention for different ToString methods allowing to use CultureInfo (see the parameter IFormatProvider which is implemented by CultureInfo) or detailed format features, standard or custom:
http://msdn.microsoft.com/en-us/library/az4se3k1.aspx[^],
http://msdn.microsoft.com/en-us/library/8kb3ddd4.aspx[^].

You are just doing wring things manipulating your string. In particular, your repeated string concatenation is bad. This is not readable and has poor performance, because strings are immutable (do I have to explain why?). The type System.Text.StringBuilder and the method string.Format are free from this problem. Using (especially repeated using of immediate constants) like "," is very bad for maintenance. You should always use explicit constant (one definition of all uses of it) or resources.

—SA