How to calculate the number of rows in a file which we have uploaded. The file might be either a text file or a CSV or Excel file.
I'm using the folowing code to get the record count like this:
Dim FileCount = From lin1 As String In File.ReadAllLines(hidFilePath.Value.ToString())
Let dd = lin1.Count
Select dd
Dim file_count As Integer = FileCount.Count
but in some cases the count is wrong.
ReadAllLines returns a string array, so you can simply take the length of the array.
Dim file_count As Integer = _
File.ReadAllLines(hidFilePath.Value.ToString()).Length
EDIT: read question to fast and answered with a loop solution
You can set your linecount as an integer and have the reader read to the end of the file.
Dim sr As New StreamReader("file path here")
Dim lineCount As Integer = System.Text.RegularExpressions.Regex.Split(sr.ReadToEnd(), Environment.NewLine).Length
sr.Close()
You can use a count variable and loop through the file until theres nothing
''name count and set it to 0
Dim count As Integer
count = 0
Dim obj As StreamReader
obj = New StreamReader("C:\...\source.txt")
''loop through the file until the end
Do Until obj.ReadLine Is Nothing
count = count + 1
Loop
''close file and show count
obj.Close()
MessageBox.Show(count)
Related
I'm looking to read lines from a text file that start with certain characters and stop when the line starts with other characters. So in my example I would like to start reading at line AB and stop at line EF however not all lines will contain the CD line. There will always be a AB line and EF line, however the number of lines in between is unknown.
Here is an example of the lines in a text file I would be reading. You can see that this will create two rows in the DataGridView however the first row is missing the CD line and should be blank.
AB-id1
EF-address1
AB-id2
CD-name1
EF-address2
Here is the code I have so far:
Dim lines() As String = File.ReadAllLines(textfile)
For i As Integer = 0 To lines.Length - 1
If lines(i).StartsWith("AB") Then
Dim nextLines As String() = lines.Skip(i + 1).ToArray
Dim info As String = nextLines.FirstOrDefault(Function(Line) Line.StartsWith("CD"))
Dim name As String = "Yes"
Dim info2 As String = nextLines.FirstOrDefault(Function(Line) Line.StartsWith("EF"))
Dim address As String = "Yes"
End If
DataGridView.Rows.Add(name,address)
Next
Now the output I currently get is:
|Yes|Yes|
|Yes|Yes|
And I should be getting:
||Yes|
|Yes|Yes|
It looks like it's reading too far down the text file and I need it to stop reading at EF. I've tried Do while and Do Until with no success. Any suggestions?
You could use the Array.FindIndex function to get the index of the next line starting with your prefix. This way you don't have to skip lines and create a new array each time.
Try this out instead:
Dim lines() As String = File.ReadAllLines(textFile)
For i As Integer = 0 To lines.Length - 1
If lines(i).StartsWith("AB") Then
Dim addressIndex As Integer = Array.FindIndex(lines, i + 1, Function(Line) Line.StartsWith("EF"))
Dim address As String = If(addressIndex <> -1, lines(addressIndex).Substring(3), "") ' Get everything past the "-"
Dim name As String = ""
If addressIndex <> -1 Then
Dim nameIndex As Integer = Array.FindIndex(lines, i + 1, addressIndex - i, Function(line) line.StartsWith("CD"))
If nameIndex <> -1 Then
name = lines(nameIndex).Substring(3) ' Get everything past the "-"
End If
End If
DataGridView.Rows.Add(name, address)
End If
Next
Sorry for the terrible wording on my last question, I was half asleep and it was midnight. This time I'll try to be more clear.
I'm currently writing some code for a mini barcode scanner and stock manager program. I've got the input and everything sorted out, but there is a problem with my arrays.
I'm currently trying to extract the contents of the stock file and sort them out into product tables.
This is my current code for getting the data:
Using fs As StreamReader = New StreamReader("The File Path (Is private)")
Dim line As String = "ERROR"
line = fs.ReadLine()
While line <> Nothing
Dim pos As Integer = 0
Dim split(3) As String
pos = products.Length
split = line.Split("|")
productCodes(productCodes.Length) = split(0)
products(products.Length, 0) = split(1)
products(products.Length, 1) = split(2)
products(products.Length, 2) = split(3)
line = fs.ReadLine()
End While
End Using
I have made sure that the file path does, in fact, go to the file. I have looked through debug to find that all the data is going through into my "split" table. The error throws as soon as I start trying to transfer the data.
This is where I declare the two tables being used:
Dim productCodes() As String = {}
Dim products(,) As Object = {}
Can somebody please explain why this is happening?
Thanks in advance
~Hydro
By declaring the arrays like you did:
Dim productCodes() As String = {}
Dim products(,) As Object = {}
You are assigning size 0 to all your arrays, so during your loop, it will eventually try to access a position that haven't been previously declared to the compiler. It is the same as declaring an array of size 10 Dim MyArray(10) and try to access the position 11 MyArray(11) = something.
You should either declare it with a proper size, or redim it during execution time:
Dim productCodes(10) As String
or
Dim productCodes() As String
Dim Products(,) As String
Dim Position as integer = 0
'code here
While line <> Nothing
Redim Preserve productCodes(Position)
Redim Preserve products(2,Position)
Dim split(3) As String
pos = products.Length
split = line.Split("|")
productCodes(Position) = split(0)
products(0,Position) = split(1)
products(1,Position) = split(2)
products(2,Position) = split(3)
line = fs.ReadLine()
Position+=1
End While
I want to read and write the same file with StreamReader and StreamWriter. I know that in my code I am trying to open the file twice and that is the problem. Could anyone give me another way to do this? I got confused a bit.
As for the program, I wanted to create a program where I create a text if it doesnt exist. If it exists then it compares each line with a Listbox and see if the value from the Listbox appears there. If it doesnt then it will add to the text.
Dim SR As System.IO.StreamReader
Dim SW As System.IO.StreamWriter
SR = New System.IO.StreamReader("D:\temp\" & Cerberus.TextBox1.Text & "_deleted.txt", True)
SW = New System.IO.StreamWriter("D:\temp\" & Cerberus.TextBox1.Text & "_deleted.txt", True)
Dim strLine As String
Do While SR.Peek <> -1
strLine = SR.ReadLine()
For i = 0 To Cerberus.ListBox2.Items.Count - 1
If Cerberus.ListBox2.Items.Item(i).Contains(strLine) = False Then
SW.WriteLine(Cerberus.ListBox2.Items.Item(i))
End If
Next
Loop
SR.Close()
SW.Close()
SR.Dispose()
SW.Dispose()
MsgBox("Duplicates Removed!")
If your file is not that large, consider using File.ReadAllLines and File.WriteAllLines.
Dim path = "D:\temp\" & Cerberus.TextBox1.Text & "_deleted.txt"
Dim lines = File.ReadAllLines(path) 'String() -- holds all the lines in memory
Dim linesToWrite = Cerberus.ListBox2.Items.Cast(Of String).Except(lines)
File.AppendAllLines(path, linesToWrite)
If the file is large, but you only have to write a few lines, then you can use File.ReadLines:
Dim lines = File.ReadLines(path) 'IEnumerable(Of String)\
'holds only a single line in memory at a time
'but the file remains open until the iteration is finished
Dim linesToWrite = Cerberus.ListBox2.Items.Cast(Of String).Except(lines).ToList
File.AppendAllLines(path, linesToWrite)
If there are a large number of lines to write, then use the answers from this question.
Consider the following code below in which for each entry in key.txt I add it to each line in plain.txt and write it to the output.txt.
Dim srKeyFile As New StreamReader("D:\Test\key.txt")
Dim srOutFile As New StreamWriter("D:\TestBial\output.txt")
Dim strKey, strPlain As String
While srKeyFile.Peek() >= 0
Dim srPlainFile As New StreamReader("D:\TestB\plain.txt")
strKey = srKeyFile.ReadLine()
Dim key As Integer = Integer.Parse(strKey)
While srPlainFile.Peek() >= 0
strPlain = srPlainFile.ReadLine()
Dim plain As Integer = Integer.Parse(strPlain)
srOutFile.WriteLine("" + (key + plain).ToString())
End While
srPlainFile.Close()
End While
srOutFile.Close()
Above I have to open and close the inner file on each iteration of the outer loop.Is there some way That I could position my pointer to beginning,each time I enter the inner loop for the file plain.txt
You can use StreamReader's BaseStream.Seek to do this, but you need to call DiscardBufferedData first:
srPlainFile.DiscardBufferedData()
srPlainFile.BaseStream.Seek(0, SeekOrigin.Begin)
I have a text file with hundreds of prospects that I'm trying to convert to csv for importing.
Format for whole document.
Prospect Name
Description
Website
Prospect Name
Description
Website
How would I write a vb program to loop through this to make a csv file. Every 4 lines is a new prospect.
Get your file contents as an IEnumerable(of String), and spin through it, adding a CSV row for every record (into a new list(of String)). Finally write the file contents. You'll probably want to add a header row.
Dim lstLines As IEnumerable(Of String) = IO.File.ReadLines("C:\test\ConvertToCSV.txt")
Dim lstNewLines As New List(Of String)
Dim intRecordTracker As Integer = 0
Dim strCSVRow As String = String.Empty
For Each strLine As String In lstLines
If intRecordTracker = 4 Then
intRecordTracker = 0
'Trim off extra comma.
lstNewLines.Add(strCSVRow.Substring(0, (strCSVRow.Length - 1)))
strCSVRow = String.Empty
End If
strCSVRow += strLine & ","
intRecordTracker += 1
Next
'Add the last record.
lstNewLines.Add(strCSVRow.Substring(0, (strCSVRow.Length - 1)))
'Finally write the CSV file.
IO.File.WriteAllLines("C:\Test\ConvertedCSV.csv", lstNewLines)
Dim count As Integer = -1, lstOutput As New List(Of String)
lstOutput.AddRange(From b In File.ReadAllLines("C:\temp\intput.txt").ToList.GroupBy(Function(x) (Math.Max(Threading.Interlocked.Increment(count), count - 1) \ 4)).ToList() Select String.Join(",", b))
File.WriteAllLines("c:\temp\test\output.txt", lstOutput)