I'm trying to copy data from text file to array, I got error Index was outside the bounds of the array.
Dim vstring(-1) As String
Dim vid(-1) As String
Dim index As Integer
Dim vText As String = ""
Dim vFileName As String = "C:\Users\suman\Documents\Visual Studio 2010\Projects\Ass3_2076004\student.txt"
Dim vAvgValue As Integer
Dim vErrorMsg As String = ""
If (Txt_IdNumber.Text).Length = 5 Then
Dim rvSR As New IO.StreamReader(vFileName)
Do While rvSR.Peek <> -1
vText = rvSR.ReadLine()
vstring = vText.Split(",")
vid(index) = vstring(0)'error
index = index + 1
Loop
Dim vstring() as String
Dim vFileName As String = "C:\Users\suman\Documents\Visual Studio 2010\Projects\Ass3_2076004\student.txt"
If Txt_IdNumber.Text.Length = 5 Then
Using rvSR As New IO.StreamReader(vFileName)
vstring = rvSR.ReadLines().Select(Function(s) s.Split(","c)(0)).ToArray()
End Using
End If
First, you should probably declare vstring as an unsized array. Like this:
Dim vString() as string
Second, Since you don't know how many lines you need, declare vid as list. Like this:
Dim vid as List(of string)
Then, before you split the string, you should make sure it actually contains a comma. Like this:
Do While rvSR.Peek <> -1
vText = rvSR.ReadLine()
If vText.Contains(",") Then
vstring = vText.Split(",")
vid.add(vstring(0))
End If
Loop
'at the end, you can convert vid from a list to an array, if you want
Dim arr() as string = vid.ToArray()
Related
I have a file location and I need to check if it exists.
The way I wan't to do it is like this:
Dim route As String = ("C:\testing1\testing2\testing3\testing4\testing5\TEXTBESTAND.txt")
If System.IO.File.Exists(route) Then
MsgBox("BESTAAT HET WERKT!")
Else
Dim subroute() As String = route.Split("\"c)
Dim counting As Integer = route.Split("\"c).Length - 1
For count2 As Integer = 0 To counting - 1
Dim firstbackslash As Integer = route.IndexOf("\")
Dim backslash As Integer = route.IndexOf("\", firstbackslash + 1)
Dim firstPart As String = route.Substring(0, backslash)
MsgBox(firstPart)
Next
What I try to accomplisch is that I fist check if folder "C:" exists then "C:\testing1" then "C:\testing1\testing2" etc.
But I cant find something like this on the internet nor with some messing around...
Here is an algorithm that that will give you all the paths starting from the root and building up to the final path including the filename. You can use this to check for each folder and create them as you go if they don't exist:
Sub Main()
Dim route As String = ("C:\testing1\testing2\testing3\testing4\testing5\TEXTBESTAND.txt")
Dim fi As New System.IO.FileInfo(route)
If Not fi.Exists Then
Dim fileName As String = Path.GetFileName(route)
Dim di As DirectoryInfo = fi.Directory
Dim pathStack As New Stack(Of String)()
pathStack.Push(di.Name)
While Not IsNothing(di.Parent)
di = di.Parent
pathStack.Push(di.Name)
End While
Dim curPath As String = ""
While pathStack.Count > 0
curPath = Path.Combine(curPath, pathStack.Pop)
' ... do something with "curPath" in here ...
' ... like check for existence and create it ...
Console.WriteLine(curPath)
End While
curPath = Path.Combine(curPath, fileName)
' ... do something with "curPath" in here ...
' ... this is the full path including the file on the end ...
Console.WriteLine(curPath)
End If
Console.Write("Press Enter to quit...")
Console.ReadLine()
End Sub
Output:
C:\
C:\testing1
C:\testing1\testing2
C:\testing1\testing2\testing3
C:\testing1\testing2\testing3\testing4
C:\testing1\testing2\testing3\testing4\testing5
C:\testing1\testing2\testing3\testing4\testing5\TEXTBESTAND.txt
Press Enter to quit...
Don't use string mnaipulation to work with file or folder paths. use the Path class.
One option:
Private Function GetExistingSubPath(fullPath As String) As String
If Directory.Exists(fullPath) OrElse File.Exists(fullPath) Then
Return fullPath
End If
Dim subPath = Path.GetDirectoryName(fullPath)
If subPath Is Nothing Then
Return Nothing
End If
Return GetExistingSubPath(subPath)
End Function
Sample usage:
Dim fullPath = "C:\testing1\testing2\testing3\testing4\testing5\TEXTBESTAND.txt"
Dim existingSubPath = GetExistingSubPath(fullPath)
Console.WriteLine(existingSubPath)
What I try to accomplisch is that I fist check if folder "C:" exists then "C:\testing1" then "C:\testing1\testing2" etc.
Noooooooooooo!
That's not how to do it at all! The file system is volatile: things can change between each of those checks. Moreover, file existence is only one of many things that can stop file access.
It's much better practice to try to access the file in question, and then handle the exception if it fails. Remember, because of the prior paragraph you have to be able to handle exceptions here anyway. .Exists() doesn't save you from writing that code. And each check is another round of disk access, which is about the slowest thing it's possible to do in a computer... even slower than unrolling the stack for an exception, which is the usual objection to this idea.
I fixed it, know I can check if multiple text files are at the locations I need, if there not I place the Textfiles at the location I need them. Then I can add something in it. (I need to put a Location of something else in it.)
Dim een As String = "C:\testing1\testing2\testing7\testing1\testing1\text.txt"
Dim twee As String = "C:\testing1\testing2\testing7\testing2\testing1\text.txt"
Dim drie As String = "C:\testing1\testing2\testing7\testing3\testing1\text.txt"
Dim vier As String = "C:\testing1\testing2\testing7\testing4\testing1\text.txt"
Dim Files As String() = {een, twee, drie, vier}
For Each route As String In Files
If System.IO.File.Exists(route) Then
MsgBox("BESTAAT HET WERKT!")
Else
Dim subroute() As String = route.Split("\"c)
Dim counting As Integer = route.Split("\"c).Length - 1
Dim tel As Integer = route.Substring(route.LastIndexOf("\") + 1).Count
Dim bestandnaam As String = route.Substring(route.LastIndexOf("\") + 1)
For count2 As Integer = 0 To route.Length - tel - 1
Dim firstbackslash As Integer = route.IndexOf("\", count2)
Dim backslash As Integer = route.IndexOf("\", count2)
Dim Mapnaam As String = route.Substring(0, backslash)
count2 = firstbackslash
If System.IO.Directory.Exists(Mapnaam) Then
Else
System.IO.Directory.CreateDirectory(Mapnaam)
End If
Next
If System.IO.File.Exists(route) Then
Else
Dim objStreamWriter As System.IO.StreamWriter
objStreamWriter = New System.IO.StreamWriter(route)
Dim label As String
Select Case route
Case een
label = "een"
Case twee
label = "twee"
Case drie
label = "drie"
Case vier
label = "vier"
End Select
Dim value As String = InputBox("Route invullen naar " & label)
'Dim objStreamWriter As New System.IO.StreamWriter(route)
objStreamWriter.Write(value)
objStreamWriter.Close()
'Using sw As System.IO.StreamWriter = System.IO.File.AppendText(route)
' sw.WriteLine(value)
'End Using
End If
End If
Next route
I would like to make a "Tolerance-calculator"
The user gives an input as string. For example:"D6" now i have to search this in the .txt file and read the next line.
I read the file like this:
Dim Findstring = IO.File.ReadAllText("....\Toleranz0.txt")
How can i find the string an the next line after the string?
Maybe:
Findstring.contains("D6") 'gives a Boolean
How does i get the correct line?
Convert your string to an array using String.Split() and find the next index or 2 indexes after "D6":
Private Sub Funcy()
Dim Findstring As String = IO.File.ReadAllText("....\Toleranz0.txt")
Dim MyCollection() As String = Findstring.Split()
Dim result As String = MyCollection(Array.IndexOf(MyCollection, "D6") + 2)
MessageBox.Show(result)
End Sub
Here's an example using ReadAllLines() as suggested by Blorgbeard:
Dim lines() As String = IO.File.ReadAllLines("....\Toleranz0.txt")
Dim index As Integer = Array.IndexOf(lines, "D6")
If index <> -1 AndAlso index <= lines.Count - 2 Then
Dim targetLine As String = lines(index + 1)
' ... do something with "targetLine" ...
Else
' either the line was not found, or there was no line after the found line
End If
i want to be able to separate the values in a textbox and display the separated values in different labels using a button
this is what i want to happen:
input "Ac2O3" on textbox
Be able to separate "Ac", "2", "O", and "3".
Show the separated values in different textboxes using a button
im using visual basic 2012
im sorry im still new to this
thanks in advance!!
You can access different character of the string with the index.
Dim input As String = "Ac2O3"
Dim part1 As String = input(0) & input(1)
Dim part2 As String = input(2)
Dim part3 As String = input(3)
Dim part4 As String = input(4)
If you don't know how to handle the button event or how to display text in a textbox, that would be different questions.
This code creates a structure called Element to make the results from the function clearer - add this to your main class that the function is going to be placed in. The main function takes a string as it's input and produced a list of structures of Element as it's output. There probably are shorter ways to do this, but I'm a fairly basic programmer who likes a puzzle - hope this helps - Dont forget to accept the answer by clicking on the tick. If you have any queries please dont hesitate to ask
Structure Element
Dim symbol As String
Dim elementCount As Int16
End Structure
Function ParseFormula(ByVal compoundString As String) As List(Of Element)
Dim tempParseFormula = New List(Of Element)
Dim firstLetter As String = "[A-Z]"
Dim secondLetter As String = "[a-z]"
Dim number As String = "[0-9]"
Dim tempElementCount As String = ""
Dim maxIndex As String = compoundString.Length - 1
Dim i As Integer = 0
Dim parsedElement As New Element
While i <= maxIndex
Dim tempChar As String = compoundString(i)
Select Case True
Case tempChar Like firstLetter
parsedElement.symbol = parsedElement.symbol & tempChar
Case tempChar Like secondLetter
parsedElement.symbol = parsedElement.symbol & tempChar
Case tempChar Like number
tempElementCount = tempElementCount & tempChar
End Select
If i = maxIndex Then
If Val(tempElementCount) = 0 Then
tempElementCount = 1
End If
parsedElement.elementCount = Val(tempElementCount)
tempParseFormula.Add(parsedElement)
parsedElement.symbol = ""
parsedElement.elementCount = 0
tempElementCount = ""
Exit While
End If
i += 1
If compoundString(i) Like firstLetter Then
If Val(tempElementCount) = 0 Then
tempElementCount = 1
End If
parsedElement.elementCount = Val(tempElementCount)
tempParseFormula.Add(parsedElement)
parsedElement.symbol = ""
parsedElement.elementCount = 0
tempElementCount = ""
End If
End While
Return tempParseFormula
End Function
I apologize if the question is a bit bland, but what I'm trying to do is access a list of things from a text file like "R1", "R2", "R3". Is it possible that I can have the integer in that name as a seperate variable?
So if I have...
Dim R0 As String = "Hello"
Dim R1 As String = "Goodbye"
Dim RCount As Integer = 0
MsgBox(R & RCount) 'Returns Hello
Not without creating and evaluating an Expression Tree, but you could use an array and an index into the array.
Dim R(6) as String
R(0) = "Hello"
R(1) = "Goodbye"
Dim RCount as Integer = 0
MsgBox(R(RCount))
I long variable in vb.net which contains the following information,
Dim g As String = "$C:\Program Files\Cavaj Java Decompiler\cavaj.exe$C:\Users\Yoosuf\AppData\Local\Google\Chrome\Application\chrome.exe$C:\Program Files\DVD Maker\dvdmaker.exe$C:\Program Files\Adobe\Adobe Photoshop CS2\ImageReady.exe$C:\Program Files\Java\jre6\bin\javaws.exe$"
The $ symbol is used as a delimiter to separate each item from the other. I need to add the exe file name at the end of each path to a listbox. However the initial process of retrieving the variable to individual array elements is not working properly.
Dim strArr() As String = g.Split("$") 'This variable is empty
For count = 0 To strArr.Length - 1
Dim arr As String = strArr(count).Split("\")
Dim strval As String = ""
For i As Integer = 3 To arr.Length - 1
strval = arr(i)
Dim j As Integer = arr.Length - 1
strval = arr(j)
Dim result As String = strval.Substring(g.Length - 5)
result = g.Substring(g.LastIndexOf("\") + 1)
ListBox1.Items.Add(result)
Next
Next
No need to do all this work. The System.IO.Path class has methods to do this for you. You want to use either System.IO.Path.GetFileName or System.IO.Path.GetFileNameWithoutExtension. Since you've already split all the file paths, just pass those paths to either of the aforementioned methods and add the result to your listbox.
Dim strArr() As String = g.Split("$")
For Each path As String In strArr
ListBox1.Items.Add(System.IO.Path.GetFileName(path))
Next
Please refer to the code below and the associated comments. Also I have comment out some code which I feel is not required based on what you want to do.
Dim strArr() As String = g.Split("$") 'This variable is empty
For count = 0 To strArr.Length - 1
Dim arr() As String = strArr(count).Split("\") ' Split returns an array
Dim strval As String = ""
For i As Integer = 3 To arr.Length - 1
'strval = arr(i)
Dim j As Integer = arr.Length - 1
strval = arr(j)
'Dim result As String = strval.Substring(g.Length - 5)
'result = g.Substring(g.LastIndexOf("\") + 1)
ListBox1.Items.Add(strval)
Next
Next