VB.Net create a string for a date from a filename with a different format

Evening,

I am working on a VB.net project with a windows form. I’m new to this so please bear with me.

Is someone able to provide some sample code on how to create a string which will display only the date in a different format? I know I am not being clear here, sorry, I don’t know the proper terminology to explain what I’m looking for. Please see my example below on what I require.

In C:\test I have the below files all written in the format “AccountNumber-YYYYMMDD-ClientName.pdf”. This filename will always be like this.

12345-20130525-John Smith.pdf
24545-20130526-Ted Wilson.pdf
2220034-20130527-Peter Shantel.pdf
423423-20130528-Kevin Charlot.pdf

I need some code which will read the file name and translate the date to “MM/DD/YYYY” in a string, so the output of the above example would look like this:

05/25/2013
05/26/2013
05/27/2013
05/28/2013

My code below writes information to a text file, where the “MM/DD/YYYY” is, is where the date will go from the file name. At the end of line 11.

'Define random numbers for comment field of each file

        Dim randomclass As New System.Random()
        Dim randomnumber As Integer

'create file from destination directory of all files

Dim str As String
        For Each rfiles As String In System.IO.Directory.GetFiles(destdir)
            randomnumber = randomclass.Next(10000, 99999)
            str = str & rfiles & "|" & System.IO.Path.GetFileNameWithoutExtension(rfiles).Split("-")(0).Trim & "|" & "_" & "||" & "docgroup" & "|" & "doctype" & "|" & "docsubtype" & "|" & "swfoi" & randomnumber & "|" & "MM/DD/YYYY" & "|" & Environment.NewLine

Next

        Dim outputname As String = [String].Format("C:\Shared\ITDept\swfoisrc\swfoi{0}.txt", DateTime.Now.ToString("MMddyyyyhhmmss"))
        System.IO.File.WriteAllText(outputname, str)

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Output of this would like like below:

C:\test\swfoi\05312013174857\12345-20130525-John Smith.pdf|12345|_||docgroup|doctype|docsubtype|swfoi20139|05/25/2013|

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Is someone able to tell me how I can achieve this?

Kind Regards,
N
LVL 1
KevinAsked:
Who is Participating?
 
Mike TomlinsonMiddle School Assistant TeacherCommented:
Add a function to your class:
    Private Function GetFormattedDateFromFileName(ByVal fileName As String) As String
        Dim parts() As String = fileName.Split("-")
        If parts.Length = 3 Then
            Dim dt As DateTime
            If DateTime.TryParseExact(parts(1), "yyyyMMdd", Nothing, Globalization.DateTimeStyles.None, dt) Then
                Return dt.ToString("MM/dd/yyyy")
            End If
        End If
        Return ""
    End Function

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Then, INSIDE your loop, pass each filename to it to get the formatted date back out, and use that value in your output:
        For Each rfiles As String In System.IO.Directory.GetFiles(destdir)

            Dim formattedDate As String = GetFormattedDateFromFileName(rfiles)

            randomnumber = randomclass.Next(10000, 99999)
            Str = Str() & rfiles & "|" & System.IO.Path.GetFileNameWithoutExtension(rfiles).Split("-")(0).Trim & "|" & "_" & "||" & "docgroup" & "|" & "doctype" & "|" & "docsubtype" & "|" & "swfoi" & randomnumber & "|" & formattedDate & "|" & Environment.NewLine

        Next

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0
 
jello024Commented:
Dim s1 = "24545-20130526-Ted Wilson.pdf"
Dim s2 = s1.Substring(s1.IndexOf("-") + 1, 8)
Dim s3 = s2.Substring(0, 4) + "-" + s2.Substring(4, 2) + "-" + s2.Substring(6, 2)
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jello024Commented:
Dim s1 = "24545-20130526-Ted Wilson.pdf"
Dim s2 = s1.Substring(s1.IndexOf("-") + 1, 8)
Dim s3 = s2.Substring(4, 2) + "/" + s2.Substring(6, 2) + "/" + s2.Substring(0, 4)
0
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KevinAuthor Commented:
This doesn't appear to work. Unless I'm doing something wrong.

See below of my code with your adjustments:

'Find date in file name and convert to MM/DD/YYYY

        Dim s1 = destdir
        Dim s2 = s1.Substring(s1.IndexOf("-") + 1, 8)
        Dim s3 = s2.Substring(4, 2) + "/" + s2.Substring(6, 2) + "/" + s2.Substring(0, 4)

        'Define random number and letters for comment field of each file

        Dim randomclass As New System.Random()
        Dim randomnumber As Integer

        'create sbt file from dest directory of all files to be indexed.

        Dim str As String
        For Each rfiles As String In System.IO.Directory.GetFiles(destdir)
            randomnumber = randomclass.Next(10000, 99999)
                   str = str & rfiles & "|" & System.IO.Path.GetFileNameWithoutExtension(rfiles).Split("-")(0).Trim & "|" & "_" & "||" & "docgroup" & "|" & "doctype" & "|" & "docsubtype" & "|" & "swfoi" & randomnumber & "|" & s3 & "|" & Environment.NewLine


        Next

        Dim outputname As String = [String].Format("C:\Shared\ITDept\swfoisrc\swfoi{0}.txt", DateTime.Now.ToString("MMddyyyyhhmmss"))
        System.IO.File.WriteAllText(outputname, str)

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Output looks like this:

C:\test\swfoi\05312013174857\12345-20130525-John Smith.pdf|12345|_||docgroup|doctype|docsubtype|swfoi20139|we/et/\\ks|

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Please let me know.

Thanks,
N
0
 
KevinAuthor Commented:
Is someone able to assist me with this issue?
0
 
KevinAuthor Commented:
Great, Thank you Idle_Mind.

I do have one question though to get an understanding of this.

What would the "parts.length = 3" represent in line 3 of the function?
0
 
Mike TomlinsonMiddle School Assistant TeacherCommented:
When you call Split() it returns an Array of Strings.

Your stated format was:

    12345-20130525-John Smith.pdf

So splitting on "-" should return exactly 3 parts:

    Index 0: 12345
    Index 1: 20130525
    Index 2: John Smith.pdf

Thus "parts.Length = 3" is checking to see if there were actually 3 parts returned by Split().   If the Length was not 3 then the filename was not in the expected format and you might want to put some of logic into the Else block of the If statement (I didn't put one into the example).
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KevinAuthor Commented:
Ahh ok i see.

Thank you so much for the explaination.

N
0
 
KevinAuthor Commented:
Idle_Mind, quick question regarding this posting.

What does the below "TryParseExact(parts(1)" refer to? What is the 1 for?

This is from your code (below).

 Private Function GetFormattedDateFromFileName(ByVal fileName As String) As String
        Dim parts() As String = fileName.Split("-")
        If parts.Length = 3 Then
            Dim dt As DateTime
            If DateTime.TryParseExact(parts(1), "yyyyMMdd", Nothing, Globalization.DateTimeStyles.None, dt) Then
                Return dt.ToString("MM/dd/yyyy")
            End If
        End If
        Return ""
    End Function
 

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0
 
Mike TomlinsonMiddle School Assistant TeacherCommented:
See my previous comment:
http://www.experts-exchange.com/Programming/Languages/.NET/Visual_Basic.NET/Q_28144561.html#a39235669

The "1" refers to the second entry of the returned array, which should be the date portion.
0
 
KevinAuthor Commented:
Ahh ok.. i see.

Thanks
0
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