Im looking for a way to create unique files in a loop, meaning that I want them to have different names for each time if loops. Im writing something that finds some values from a html and does that in a loop. It doesnt matter what the file is called since its deleted shortly after (just a temporary file to store two lines) but they have to be saved in the same directory. Can I create a sort of array for the files? I have a feeling that its quite easy but I just can't see it at the moment.
Hope you can help me.
Cheers,
Snoop
If it doesn't matter at all you could use a Guid:
Dim directory = "Folder-Path"
Dim fileName = String.Format("{0}.txt", Guid.NewGuid())
Dim fullPath = System.IO.Path.Combine(directory, fileName)
Related
I want get the oldest creation file in a directory but want to exclude the file ‘Startup’(Which is currently the oldest file). So I would like to skip that file and get the next oldest creation file in the directory which would be ‘TEST’.
This code only gets the Startup.
Dim oldestFile = folderlist.OrderBy(Function(fi) fi.CreationTime).First
1:
You use the Where function to filter.
Dim folder As New DirectoryInfo(folderPath)
Dim oldestFile = folder.EnumerateFiles().
Where(Function(fi) fi.Name <> "Startup.txt").
OrderBy(Function(fi) fi.CreationTime).
First()
Note that it is preferable to use EnumerateFiles rather than GetFiles unless you really want access to the full array of files after the fact. If you only need that one file, EnumerateFiles is better because it doesn't get all the files first and then perform the other operations on that array. You may already know this but most people don't at first.
Note also that I'm assuming that those are text files based on the icons. Change the name in the filter if they are something else. As a developer, you really ought to switch off the File Explorer feature that hides file extensions. That's for people who don't understand computers.
Question, if anyone could help please: The file I am reading from inPath is very large 300MB to 1 GB +. I need to load the file into the variable wholeFile as shown in the below program. Approximately 200 MB files works fine but larger files bomb out (Out of Memory Exception Error). The purpose is once file is loaded into the variable, I would need to run RegEx and pick certain section of the file and save somewhere else. Thanks once again for your kind attention.
Dim inPath As String = "C:\temp\300MB-File.txt"
Dim outPath As String = "C:\temp\myFileNew2.txt"
Dim wholeFile as String = ""
Using sw As StreamWriter = File.CreateText(outPath)
For Each oneLine As String In File.ReadLines(inPath)
sw.WriteLine(oneLine)
wholeFile = wholeFile & vbCrLf & oneLine
Next
End Using
The way you're doing that is abominable. Why would you read a file line by line if your purpose is to store the entire contents in a single variable? Why wouldn't you load the whole file in one go?
Dim fileContents = File.ReadAllText(filePath)
That may still have memory issues with large files but the way you're doing will use exponentially more memory. Each time you do that concatenation to the String, you create a new String object and copy the previous contents into it along with the new text. That means that, for a file with N lines, you are going to create N Strings. The first will contain the first line, then the second will contain the first two lines, then the third will contain the first three lines, etc, etc.
If you really want to read the file line by line then you could use a StringBuilder, which avoids so much memory reallocation. Even better would be to get the size of the file first and then create the StringBuilder with the appropriate capacity from the get go, so no reallocation would be needed at all.
When you get right down to it though, files of that size are going to be an issue no matter what. You will either need to ensure that enough memory is allocated to your app to handle it or else you'll have to break the file up into chunks and process each chunk separately. If your regex won't match very large portions of the file then you can simply make each chunk overlap by a line or two and then handle the special cases where you get duplicate matches in the overlapping section.
I'm making a console application and I want to see what files is in a folder
For Each foundFile As String In My.Computer.FileSystem.GetFiles("c:\users\zac\desktop\booked vehicle\requested\")
Console.WriteLine(foundFile)
Next
after using this code and find that the folder is empty I need an If statement that say's
If foundfile has no files then
tell user no files found
end if
but I don't know how to write this so Visual Basic understands.
Load the files into a variable then check the count.
Dim files = My.Computer.FileSystem.GetFiles("c:\users\zac\desktop\booked vehicle\requested\")
If files.Count = 0 Then
'tell user no files
Else
For Each file In files
Console.WriteLine(file)
Next
End If
FileSystem.GetFiles() returns a collection of file name strings. As OneFineDay showed, you can use the collection's Count property to know if any files were found.
The downside of using FileSystem.GetFile() is that it has to search the entire folder before then returning the entire list of filenames. If you are searching large folders and speed is an issue, consider using Directory.EnumerateFiles() instead. That way, you can output a message if no file was found, otherwise loop throuh the list of found files. For example:
Dim files = Directory.EnumerateFiles("c:\users\zac\desktop\booked vehicle\requested\").GetEnumerator()
If files.MoveNext Then
' files were found
Do
Console.WriteLine(files.Current)
Loop Until Not files.MoveNext
Else
' no files were found
End If
I personally would use Linq to accomplish this. It's very quick and efficient to use in this case. I put the Console.ReadLine() at the end to show the files, you can remove this if need to be. Also you can change the Console.WriteLine to not include the string (s) if you don't want to. The s was declared if you want to show the files and also to see if there are any files. As I said, this was for my viewing to see the files. Straight to the point!
Dim s As String = String.Join(Environment.NewLine, New DirectoryInfo("YOUR DIRECTORY").GetFiles().[Select](Function(file) file.Name).ToArray)
Console.WriteLine(If(s.Length > 0, s, "No files found!"))
Console.ReadLine()
I am looking for mail merge alternatives in my vb.net app. I have used the mail merge feature of word, and find that it is quite buggy when dealing with a large volume of documents. I am looking at alternate methods of generating the merge, and have come across open xml. I think this will probably be the answer I am looking for. I have come to understand that the merge will be entirely code-driven in vb.net. I have started playing around with the following code:
Dim wordprocessingDocument As WordprocessingDocument = wordprocessingDocument.Open("C:\Users\JasonB\Documents\test.docx", True)
'for each simplefield (mergefield)
For Each field In wordprocessingDocument.MainDocumentPart.Document.Body.Descendants(Of SimpleField)()
'get the document instruction values
Dim instruction As String() = field.Instruction.Value.Split(splitChar, StringSplitOptions.RemoveEmptyEntries)
'if mergefield
If instruction(0).ToLower.Equals("mergefield") Then
Dim fieldname As String = instruction(1)
For Each fieldtext In field.Descendants(Of Text)()
fieldtext.Text = "I AM TESTING"
Next
End If
wordprocessingDocument.MainDocumentPart.Document.Save()
wordprocessingDocument.Dispose()
Now this works great and all, but I am realizing that I need to create as many documents as I will have datarows (assuming I use a datatable to handle the data).
One suggestion I found was to loop through each datarow, take my document template, save it to a folder and insert the datarow data. This could mean however that I end up with 12,000 documents in a single folder that need to be joined later and converted to pdf.
Is there another option? The other thing that stood out to me is to create a new word document, and duplicate over the xml from the template, and then replace the values. I dont know however if there is a "simpler" way of doing this, thanks.
If you don't want to save all 12,000 documents to file you should be able to process, convert and email them one at a time using temporary files.
Converting the DOCX to PDF in .NET might be an issue but looks like it's possible using Word Automation (Saving Word DOCX files as PDF).
The bottom line is you don't need to generate all documents before emailing them if you perform the process one document at a time. You can use SmtpClient in VB.NET to email the PDF after it is generated.
In terms of creating the document I have seen reports generated where a simple string replace is used to replace a string such as '%FIRSTNAME%' with the person's name and so on. This isn't necessarily the best approach but can work quite well. This way you can create your template in Word or OpenOffice and then edit it in .NET using OpenXML.
I'm trying to pull the creation date of all the files (1000+) in a folder on a local server to list in an excel file. I've been trying to use FileSystemInfo for this, but it doesn't seem to work to get the creation date of MULTIPLE files because it doesn't allow me to use wildcard characters to read all (not even sure if that's what I'll need to do). Has anyone ever done this?
This should help you loop through all of the files:
Dim dirinfo As New DirectoryInfo("C:\somefolder")
For Each fsi As FileSystemInfo In dirinfo.GetFileSystemInfos()
debug.print(fsi.CreationTime)
Next
Some things to read up on:
For loops
FileSystemInfo Class
DirectoryInfo Class