I'm looping through a zip file trying to add the file name of each file within.
Is this the correct method?
Dim ZipNameArray(?)
Using zip As ZipFile = ZipFile.Read(ZipToUnpack)
For Each file In zip
ZipNameArray(?) = file .FileName
Next
End Using
I do not know the array size until I start looping through the zip (To work out the number of files within).
How do I increment the Array? file is not a number? (It's a ZipEntry)
I would use an generic List(of ZipFile) for this. They are more fail-safe and easier to read.
Dim zips as new List(of ZipFile)
Using zip As ZipFile = ZipFile.Read(ZipToUnpack)
For Each file In zip
zips.add(file)
Next
End Using
And when you want to iterate through:
For each zip as ZipFile in zips
dim fileName as string=zip.FileName
Next
In 99% you can forget Arrays in .Net and when you need one you get it with List.ToArray
You could use an ArrayList object, add the items to it, then call .ToArray() at the end to get an array of ZipEntry objects.
Since you don't know the array size there are two options. You could go through the Zip file twice. The first time just count the number of files, then create your array and then go through a second time to add the name of each file.
If your zip file is too large you could always initialize your array to some constant number (say 10) and when you reach the eleventh filename you grow your array by "redim"ing it
For example:
Dim Names(10) as String
Dim counter as Integer
counter = 0
Go through zip {
counter += 1
if counter = size of Names then
ReDim Preserve Names(size of Names + 10)
add fileName
}
More information about arrays (including redim) is here.
Dim zipNameArray As String()
Using zip As ZipFile = ZipFile.Read(ZipToUnpack)
zipNameArray = zip.Select(Function(file) file.FileName).ToArray()
End Using
Related
First things first, I did a search before posting this question but the answers are so generic that I could not find anything similar to what I'm trying to do. I apologize in advance if this has been answered before and I did not find it.
I have a scenario where I already collected a large list of rows (>10K) from the SQL server and put into an array (List) of strings. These rows are consisted of filenames. Because I already put them on a list, I don't want to query the SQL server again and instead want work with what I already have in memory.
This is the code I'm trying to get right:
'Valid file types for InfoLink1, InfoLink2, InfoLink3
Dim lstValidImageFormats As New List(Of String)({".JPG", ".JPEG", ".JPE", ".BMP", ".PNG", ".TIF", ".TIFF", ".GIF"})
Dim lstValidSTLFormats As New List(Of String)({".STL"})
Dim lstValidSTEPFormats As New List(Of String)({".STP", ".STEP"})
'////////////////
'// Components //
'////////////////
'We don't check Parts.InfoLink because all formats are allowed in this field
'Parts.InfoLink1 - File in Infolink1 columns MUST BE images
For i = 0 To arrStrComponentsInfolink1Values.Count - 1 'We have 10K rows with filenames in this list
For Each FileExtension As String In lstValidImageFormats
If arrStrComponentsInfolink1Values.Item(i).EndsWith(FileExtension) = False Then
End If
Next
Next
I'm trying to parse each item (filename) I have in the array arrStrComponentsInfolink1Values and check if the filename DOES NOT end with one of the extensions in the list lstValidImageFormats. If it doesn't, then I'll send the filename to another list (array).
My difficulty here is about how to iterate through each item in arrStrComponentsInfolink1Values, then check if each filename ends with one of the extensions declared in lstValidImageFormats, do what I want to do with the item if it DOES NOT end with one of those extensions, and then proceed to parse the next item in arrStrComponentsInfolink1Values.
I sincerely don't know what's the best way/performance efficient to do that.
My code above is empty because algorithmically I don't know the best approach to do what I want without querying the SQL server again with something like AND filename NOT LIKE '%.JPG' AND filename NOT LIKE '%.JPEG' AND filename NOT LIKE '%.JPE' AND filename NOT LIKE '%.BMP'...
Because I already have the data in the memory in a list, performance would be much better if I could use what I already have.
Any suggestions or material I could read to learn how to do what I'm looking for?
Thank you!
Here's how I would tackle this:
Dim invalidFormatFiles = _
From x In arrStrComponentsInfolink1Values _
Let fi = New FileInfo(x) _
Where Not lstValidImageFormats.Contains(fi.Extension.ToUpperInvariant()) _
Select x
For Each invalidFormatFile In invalidFormatFiles
' Do your processing
Next
I ended up doing this and it worked:
Dim lstValidImageFormats As New List(Of String)({".JPG", ".JPEG", ".JPE", ".BMP", ".PNG", ".TIF", ".TIFF", ".GIF"})
Dim lstValidSTLFormats As New List(Of String)({".STL"})
Dim lstValidSTEPFormats As New List(Of String)({".STP", ".STEP"})
'////////////////
'// Components //
'////////////////
'We don't check Parts.InfoLink because all formats are allowed in this field
'Parts.InfoLink1 - File in Infolink1 columns MUST BE images
Dim intExtCounter As Integer = 0
For i = 0 To arrIntComponentsInfolink1UNRs.Count - 1 'We have 10K rows with filenames in this list
intExtCounter = 0
For j = 0 To lstValidImageFormats.Count - 1
If arrStrComponentsInfolink1Values.Item(i).EndsWith(lstValidImageFormats.Item(j)) = True Then
intExtCounter += 1
End If
Next
If intExtCounter = 0 Then 'At least one file extension was found
arrIntComponentsInfolink1UNRsReportSectionInvalidExtensions.Add(i) 'File extension is not in the list of allowed extensions
End If
Next
But #41686d6564 answer was the best solution:
Dim newList = arrStrComponentsInfolink1Values.Where(Function(x) Not lstValidImageFormats.Contains(IO.Path.GetExtension(x))).ToList()
Thank you!
I have a question which asks me to calculate something from an input file. The problem is, the lines in the file don't use any special character as delimiter, like , or |. I will show it down below.
Data Communication
20
Visual Basic
40
The output I need to write to another file should look like this:
Data communication 20
Visual Basic 40
Total Books : 60
The problem is, how can I specify the delimiter? Like when there is a symbol as in strArray = strLine.Split(","). Since there is nothing I can use as delimiter, how can I split the file content?
There's no real need to split the text in the input file, when you can read a file line by line using standard methods.
You can use, e.g., a StreamReader to read the lines from the source file, check whether the current line is just text or it can be converted to a number, using Integer.TryParse and excluding empty lines.
Here, when the line read is not numeric, it's added as a Key in a Dictionary(Of String, Integer), unless it already exists (to handle duplicate categories in the source file).
If the line represents a number, it's added to the Value corresponding to the category Key previously read, stored in a variable named previousLine.
This setup can handle initial empty lines, empty lines in the text body and duplicate categories, e.g.,
Data Communication
20
Visual Basic
40
C#
100
Visual Basic
10
Other stuff
2
C++
10000
Other stuff
1
If a number is instead found in the first line, it's treated as a category.
Add any other check to handle a different structure of the input file.
Imports System.IO
Imports System.Linq
Dim basePath = "[Path where the input file is stored]"
Dim booksDict = New Dictionary(Of String, Integer)
Dim currentValue As Integer = 0
Dim previousLine As String = String.Empty
Using sr As New StreamReader(Path.Combine(basePath, "Books.txt"))
While sr.Peek > -1
Dim line = sr.ReadLine().Trim()
If Not String.IsNullOrEmpty(line) Then
If Integer.TryParse(line, currentValue) AndAlso (Not String.IsNullOrEmpty(previousLine)) Then
booksDict(previousLine) += currentValue
Else
If Not booksDict.ContainsKey(line) Then
booksDict.Add(line, 0)
End If
End If
End If
previousLine = line
End While
End Using
Now, you have a Dictionary where the Keys represent categories and the related Value is the sum of all books in that category.
You can Select() each KeyValuePair of the Dictionary and transform it into a string that represents the Key and its Value (Category:Number).
Here, also OrderBy() is used, to order the categories alphabetically, in ascending order; it may be useful.
File.WriteAllLines is then called to store the strings generated.
In the end, a new string is appended to the file, using File.AppendAllText, to write the sum of all books in all categories. The Sum() method sums all the Values in the Dictionary.
Dim newFilePath = Path.Combine(basePath, "BooksNew.txt")
File.WriteAllLines(newFilePath, booksDict.
Select(Function(kvp) $"{kvp.Key}:{kvp.Value}").OrderBy(Function(s) s))
File.AppendAllText(newFilePath, vbCrLf & "Total Books: " & booksDict.Sum(Function(kvp) kvp.Value).ToString())
The output is:
C#:100
C++:10000
Data Communication:20
Other stuff:3
Visual Basic:50
Total Books: 10173
Sure.. System.IO.File.ReadAllLines() will read the whole file and split into an array based on newlines, so you'll get an array of 4 elements. You can process it with a flipflop boolean to get alternate lines, or you can try and parse the line to a number and if it works, then its a number and if not, it's a string. If it's a number take the string you remembered (using a variable) from the previous loop
Dim arr = File.ReadALlLines(...)
Dim isStr = True
Dim prevString = ""
For Each s as String in arr
If isStr Then
prevString = s
Else
Console.WriteLine($"The string is {prevString} and the number is {s}")
End If
'flip the boolean
isStr = Not isStr
Next s
I used File.ReadAllLines to get an array containing each line in the file. Since the size of the file could be larger than the sample shown, I am using a StringBuilder. This save having to throw away and create a new string on each iteration of the loop.
I am using interpolated strings indicated by the $ preceding the quotes. This allows you to insert variables into the string surrounded by braces.
Note the Step 2 in the For loop. i will increment by 2 instead of the default 1.
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim lines = File.ReadAllLines("input.txt")
Dim sb As New StringBuilder
Dim total As Integer
For i = 0 To lines.Length - 2 Step 2
sb.AppendLine($"{lines(i)} {lines(i + 1)}")
total += CInt(lines(i + 1))
Next
sb.AppendLine($"Total Books: {total}")
TextBox1.Text = sb.ToString
End Sub
File Structure
RECORD
1234567890,123456789,1234567,Address1,,City,State,Zip,USA,Phone,,,,,,,,,
EmpName,DBAName,ID,,Address1,,Address1,City,60603,USA,234567890,,,,
C,03/13/2017,,1,2,
RECORD
1234567890,123456789,1234567,Address1,,City,State,Zip,USA,Phone,,,,,,,,,
EmpName2,DBAName2,ID2,,Address2,,Address2,City2,60603,USA,234567890,,,,
C,03/13/2017,,1,2,
Looking at the above file structure, I want to loop through file and for each record(RECORD), I want to put next three lines in one array and then next record in separate array.
I am looking for skeleton code, I am very new in programming using stream readers.
Code so far
Dim read As New System.IO.StreamReader("C:\New Text.txt")
Dim a As String
For Each a In read.ReadLine
If read.ReadLine.Equals("RECORD") Then
\\How do I read next 3 lines and put them in one array with comma delimiter
End If
Next
You need a data structure where you will keep the lines loaded and then start your loop
' Here you will keep the 3 lines block joined together and splitted on comma
Dim records = new List(Of String())()
Using read As New System.IO.StreamReader("C:\New Text.txt")
Dim a As String
' Read each line (Assuming that we start with a RECORD line
For Each a In read.ReadLine
' Do not read another line, but just test what is present in the string
If a.Equals("RECORD") Then
' Now read the 3 following lines....
Dim line1 = read.ReadLine
Dim line2 = read.ReadLine
Dim line3 = read.ReadLine
'Join the lines togeter
Dim record = string.Join("", line1, line2, line3).
' Split on the comma to produce an array of strings. The fields.
Dim fields = record.Split(","c)
records.Add(fields)
End If
Next
End Using
Of course this should be enhanced using a proper class that describe your inputs where each property of the class represent a field of the CSV file loaded. And then you could change the List(Of String()) to a List(Of YourClassData)
Keep in mind that this solution is extremely dependant of an exact file structure. A line with the "RECORD" content should be always followed by three lines of data. (No blank lines allowed between the three data lines)
Dim read As New System.IO.StreamReader("C:\New Text.txt")
//I usually only do C#, but rough VB.NEt code: I did not rcreate your array for you, figured you got that :-)
Dim a As String
Dim myConcatString as String
For Each a In read.ReadLine
Dim myReadLine as String
myReadLine = read.ReadLine
If myReadLine.Equals("RECORD") Then
myConcatString = myConcatString & myReadLine
\\How do I read next 3 lines and put them in one array with comma delimiter
else
//add myConcatString to array if not null....
myConcatString =""
End If
Next
I had built a project that read data from a report and it used to work fine but now for some reason the report puts every thing in to strings. So I want to modify my stream reader to remove or ignore the quotes as it reads the lines.
This is a snipet of the part that reads the lines.
Dim RawEntList As New List(Of Array)()
Dim newline() As String
Dim CurrentAccountName As String
Dim CurrentAccount As Account
Dim AccountNameExsists As Boolean
Dim NewAccount As Account
Dim NewEntry As Entrey
Dim WrongFileErrorTrigger As String
ListOfLoadedAccountNames.Clear()
'opens the file
Try
Dim sr As New IO.StreamReader(File1Loc)
Console.WriteLine("Loading full report please waite")
MsgBox("Loading full report may take a while.")
'While we have not finished reading the file
While (Not sr.EndOfStream)
'spliting eatch line up into an array
newline = sr.ReadLine.Split(","c)
'storring eatch array into a list
RawEntList.Add(newline)
End While
And then of course I iterate through the list to pull out information to populate objects like this:
For Each Entr In RawEntList
CurrentAccountName = Entr(36)
AccountNameExsists = False
For Each AccountName In ListOfLoadedAccountNames
If CurrentAccountName = AccountName Then
AccountNameExsists = True
End If
Next
You could just do
StringName.Replace(ControlChars.Quote, "")
or
StringName.Replace(Chr(34), "")
OR
streamReader.readline.split().Replace(Chr(34), "")
How about doing the replace before the split, after the readline? That should save iteration multiplication, or better yet (if possible), do a replace on the entire file (if the data is formatted in the way it can be done & you have enough memory) using the ReadAllText method of the File object, do your replace, then read the lines from memory to build your array (super fast!).
File.ReadAllText(path)
I am trying to loop through the contents of a text file reading the text file line by line. During the looping process there is several times I need to use the files contents.
Dim xRead As System.IO.StreamReader
xRead = File.OpenText(TextBox3.Text)
Do Until xRead.EndOfStream
Dim linetext As String = xRead.ReadLine
Dim aryTextFile() As String = linetext.Split(" ")
Dim firstname As String = Val(aryTextFile(0))
TextBox1.Text = firstname.ToString
Dim lastname As String = Val(aryTextFile(0))
TextBox2.Text = lastname.ToString
Loop
Edit: What I am trying to do is read say the first five items in a text file perform some random processing then read the next 5 lines of the text file.
I would like to be able to use the lines pulled from the text file as separated string variables.
It is not clear why you would need to have 5 lines stored at any time, according to your code sample, since you are only processing one line at a time. If you think that doing 5 lines at once will be faster - this is unlikely, because .NET maintains caching internally, so both approaches will probably perform the same. However, reading one line at a time is a much more simple pattern to use, so better look into that first.
Still, here is an approximate version of the code that does processing every 5 lines:
Sub Main()
Dim bufferMaxSize As Integer = 5
Using xRead As New System.IO.StreamReader(TextBox3.Text)
Dim buffer As New List(Of String)
Do Until xRead.EndOfStream
If buffer.Count < bufferMaxSize Then
buffer.Add(xRead.ReadLine)
Continue Do
Else
PerformProcessing(buffer)
buffer.Clear()
End If
Loop
If buffer.Count > 0 Then
'if line count is not divisible by bufferMaxSize, 5 in this case
'there will be a remainder of 1-4 records,
'which also needs to be processed
PerformProcessing(buffer)
End If
End Using
End Sub
Here is mine . Rely easy . Just copy the location from the file and copy1 folder to does locations . This is my first program :) . ready proud of it
Imports System.IO
Module Module1
Sub Main()
For Each Line In File.ReadLines("C:\location.txt".ToArray)
My.Computer.FileSystem.CopyDirectory("C:\Copy1", Line, True)
Next
Console.WriteLine("Done")
Console.ReadLine()
End Sub
End Module