I need to find consecutive numbers in an array and return a string which tells the range and numbers that don't form a range.
I found some of the already asked questions but none of them is in VB.Net:
Add to array consecutive numbers
If the array of numbers looks like {11,12,67,68,69,70,92,97} then returned string should be of the form 11,12, 67 through 70, 92 and 97.
This is not homework; I need this function for a word document containing statistical data.
Entered directly into the reply window, so there's almost certainly a bug or three:
Public Class Range
Public Shared Function PrintRanges(ByVal numbers() As Integer) As String
Dim buffer As New List(Of Range)()
Dim CurrentRange As Range = Nothing
For Each i As Integer in numbers ' you may want to add a .OrderBy() here
If CurrentRange IsNot Nothing AndAlso i - 1 = CurrentRange.EndValue Then
CurrentRange.Increase()
Else
CurrentRange = New Range(i)
buffer.Add(CurrentRange)
End If
Next i
'Got a little lazy for this line - it still does a ", " rather than " and " for the final delimiter. Simple code to fix it, just tedious.
Return String.Join(", ", buffer.Select(Function(r) r.ToString()).ToArray())
End Function
Private Sub New(ByVal InitialValue As Integer)
EndValue = IntialValue
Length = 1
End Sub
'For completeness, these two properties should be made read only outside the class, but the private constructor makes that largely moot
Public Property EndValue As Integer
Public Property Length As Integer
Public Sub Increase()
Length += 1
EndValue += 1
End Sub
Public Overrides Function ToString() As String
If Length == 1 Then Return EndValue.ToString()
If Length == 2 Then Return (EndValue -1).ToString() & "," & LastValue.ToString()
Return (EndValue - Length).ToString() & " through " & EndValue.ToString()
End Function
End Class
Related
I would like to ask for your help regarding my problem. I want to create a module for my program where it would read .txt file, find a specific value and insert it to the text box.
As an example I have a text file called system.txt which contains single line text. The text is something like this:
[Name=John][Last Name=xxx_xxx][Address=xxxx][Age=22][Phone Number=8454845]
What i want to do is to get only the last name value "xxx_xxx" which every time can be different and insert it to my form's text box
Im totally new in programming, was looking for the other examples but couldnt find anything what would fit exactly to my situation.
Here is what i could write so far but i dont have any idea if there is any logic in my code:
Dim field As New List(Of String)
Private Sub readcrnFile()
For Each line In File.ReadAllLines(C:\test\test_1\db\update\network\system.txt)
For i = 1 To 3
If line.Contains("Last Name=" & i) Then
field.Add(line.Substring(line.IndexOf("=") + 2))
End If
Next
Next
End Sub
Im
You can get this down to a function with a single line of code:
Private Function readcrnFile(fileName As String) As IEnumerable(Of String)
Return File.ReadLines(fileName).Where(Function(line) RegEx.IsMatch(line, "[[[]Last Name=(?<LastName>[^]]+)]").Select(Function(line) RegEx.Match(line, exp).Groups("LastName").Value)
End Function
But for readability/maintainability and to avoid repeating the expression evaluation on each line I'd spread it out a bit:
Private Function readcrnFile(fileName As String) As IEnumerable(Of String)
Dim exp As New RegEx("[[[]Last Name=(?<LastName>[^]]+)]")
Return File.ReadLines(fileName).
Select(Function(line) exp.Match(line)).
Where(Function(m) m.Success).
Select(Function(m) m.Groups("LastName").Value)
End Function
See a simple example of the expression here:
https://dotnetfiddle.net/gJf3su
Dim strval As String = " [Name=John][Last Name=xxx_xxx][Address=xxxx][Age=22][Phone Number=8454845]"
Dim strline() As String = strval.Split(New String() {"[", "]"}, StringSplitOptions.RemoveEmptyEntries) _
.Where(Function(s) Not String.IsNullOrWhiteSpace(s)) _
.ToArray()
Dim lastnameArray() = strline(1).Split("=")
Dim lastname = lastnameArray(1).ToString()
Using your sample data...
I read the file and trim off the first and last bracket symbol. The small c following the the 2 strings tell the compiler that this is a Char. The braces enclosed an array of Char which is what the Trim method expects.
Next we split the file text into an array of strings with the .Split method. We need to use the overload that accepts a String. Although the docs show Split(String, StringSplitOptions), I could only get it to work with a string array with a single element. Split(String(), StringSplitOptions)
Then I looped through the string array called splits, checking for and element that starts with "Last Name=". As soon as we find it we return a substring that starts at position 10 (starts at zero).
If no match is found, an empty string is returned.
Private Function readcrnFile() As String
Dim LineInput = File.ReadAllText("system.txt").Trim({"["c, "]"c})
Dim splits = LineInput.Split({"]["}, StringSplitOptions.None)
For Each s In splits
If s.StartsWith("Last Name=") Then
Return s.Substring(10)
End If
Next
Return ""
End Function
Usage...
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
TextBox1.Text = readcrnFile()
End Sub
You can easily split that line in an array of strings using as separators the [ and ] brackets and removing any empty string from the result.
Dim input As String = "[Name=John][Last Name=xxx_xxx][Address=xxxx][Age=22][Phone Number=8454845]"
Dim parts = input.Split(New Char() {"["c, "]"c}, StringSplitOptions.RemoveEmptyEntries)
At this point you have an array of strings and you can loop over it to find the entry that starts with the last name key, when you find it you can split at the = character and get the second element of the array
For Each p As String In parts
If p.StartsWith("Last Name") Then
Dim data = p.Split("="c)
field.Add(data(1))
Exit For
End If
Next
Of course, if you are sure that the second entry in each line is the Last Name entry then you can remove the loop and go directly for the entry
Dim data = parts(1).Split("="c)
A more sophisticated way to remove the for each loop with a single line is using some of the IEnumerable extensions available in the Linq namespace.
So, for example, the loop above could be replaced with
field.Add((parts.FirstOrDefault(Function(x) x.StartsWith("Last Name"))).Split("="c)(1))
As you can see, it is a lot more obscure and probably not a good way to do it anyway because there is no check on the eventuality that if the Last Name key is missing in the input string
You should first know the difference between ReadAllLines() and ReadLines().
Then, here's an example using only two simple string manipulation functions, String.IndexOf() and String.Substring():
Sub Main(args As String())
Dim entryMarker As String = "[Last Name="
Dim closingMarker As String = "]"
Dim FileName As String = "C:\test\test_1\db\update\network\system.txt"
Dim value As String = readcrnFile(entryMarker, closingMarker, FileName)
If Not IsNothing(value) Then
Console.WriteLine("value = " & value)
Else
Console.WriteLine("Entry not found")
End If
Console.Write("Press Enter to Quit...")
Console.ReadKey()
End Sub
Private Function readcrnFile(ByVal entry As String, ByVal closingMarker As String, ByVal fileName As String) As String
Dim entryIndex As Integer
Dim closingIndex As Integer
For Each line In File.ReadLines(fileName)
entryIndex = line.IndexOf(entry) ' see if the marker is in our line
If entryIndex <> -1 Then
closingIndex = line.IndexOf(closingMarker, entryIndex + entry.Length) ' find first "]" AFTER our entry marker
If closingIndex <> -1 Then
' calculate the starting position and length of the value after the entry marker
Dim startAt As Integer = entryIndex + entry.Length
Dim length As Integer = closingIndex - startAt
Return line.Substring(startAt, length)
End If
End If
Next
Return Nothing
End Function
Using VB I am trying to create a name for the file by concatenating together the words "NewEmployeesOut" with the short date and time of the day. I am getting the following error System.NotSupportedException: 'The given path's format is not supported.' Below is the Code I am currently using, it seems like VB does not like a character I am using in my concat function when trying to export the .txt file.
Private Sub btnWrite_Click(sender As Object, e As EventArgs) Handles btnWrite.Click
Dim writeRecord As New StreamWriter
(New FileStream("NewEmployeesOut" & Date.Today.ToShortDateString & Date.Now.ToShortTimeString & ".txt", FileMode.Append, FileAccess.Write))
Dim EmployeeInformation1 As New EmployeeInformation()
writeRecord.Write(EmployeeInformation1.LastName & "|")
writeRecord.Write(EmployeeInformation1.FirstName & "|")
writeRecord.Write(EmployeeInformation1.DepartmentNo & "|")
writeRecord.Write(EmployeeInformation1.CreateUserName(EmployeeInformation1.FirstName, EmployeeInformation1.LastName) & "|")
writeRecord.WriteLine(EmployeeInformation1.CreatePassword)
writeRecord.Close()
End Sub
From MS docs https://learn.microsoft.com/en-us/windows/win32/fileio/naming-a-file
The following characters are resevered.
< (less than)
> (greater than)
: (colon)
" (double quote)
/ (forward slash)
\ (backslash)
| (vertical bar or pipe)
? (question mark)
* (asterisk)
A file name formatted as follows will pass muster. The uppercase HH gives you 24 hour time.
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
Dim fileName As String = "NewEmployeesOut" & Now.ToString(" MMMM dd, yyyy HH,mm") & ".txt"
Debug.Print(fileName)
File.CreateText(fileName)
End Sub
In the immediate window...
NewEmployeesOut December 10, 2020 18,07.txt
Your short date probably looks like "31/12/2020" or "12/31/2020" which are no valid file names. Try something like
Dim now As DateTime = DateTime.Now
Dim fileName As String = $"NewEmployeesOut_{now:yyyy-MM-dd}_{now:HHmm}.txt"
Concerning the other question: It's the wrong place to post it, don't ask another question within a comment.
I think you have to learn a bit the basics first, read/watch some VB.Net tutorials and maybe some clean-code principles like the clean-code-techniques. Your questions suggest that you don't know yet how to write simple code.
Try to structure what you are doing, avoid (like in your example) to copy 4 times the same lines of code but to create functions instead to encapsulate business logic. e.g. writing a file has nothing to do with assembling a file name, therefore the two things should not be conducted in the same method etc.
But this all said, here an idea how you could structure your code (from the comment not the main question), although I'm not too positive about the usability of the two random digits...
Usage:
Dim fileName As String = GetFileName("Smith", "John")
Methods/Properties:
Private Shared Function GetFileName(lastName As String, firstName As String) As String
lastName = NormalizeAndCrop(lastName, 7)
firstName = NormalizeAndCrop(firstName, 10)
Dim randomNumber As Int32 = Randomizer.Next(0, 100)
Return $"{lastName}{firstName}{randomNumber:00}"
End Function
Private Shared Function NormalizeAndCrop(text As String, length As Int32)
'Check args
If (length < 0) Then Throw New ArgumentOutOfRangeException(NameOf(length), length, "A non-negative value expected!")
If (text Is Nothing) OrElse (length = 0) Then Return String.Empty
text = text.Normalize()
'Copy only valid characters
Dim result As New StringBuilder()
For i As Int32 = 0 To text.Length - 1
Dim c As Char = text(i)
If (IsValidFileNameChar(c)) Then
result.Append(c)
If (result.Length = length) Then
Return result.ToString()
End If
End If
Next
Return result.ToString()
End Function
Private Shared Function IsValidFileNameChar(c As Char) As Boolean
If (Char.IsControl(c)) Then Return False
If (InvalidFileNameChars.IndexOf(c) > -1) Then Return False
Return True
End Function
Private Shared ReadOnly Property Randomizer As Random = New Random(Environment.TickCount)
Private Shared ReadOnly Property InvalidFileNameChars As String = New String(Path.GetInvalidFileNameChars())
Hi I need to change WordCount and CountVowel procedures to functions and create a function to count number of consonants in a string.
I have done these two procedures but I cannot figure out how to do the last part. I am fairly new to programming.
My current code is given below:
Sub Main()
Dim Sentence As String
Console.WriteLine("Sentence Analysis" + vbNewLine + "")
Console.WriteLine("Enter a sentence, then press 'Enter'" + vbNewLine + "")
Sentence = Console.ReadLine()
Console.WriteLine("")
Call WordCount(Sentence)
Call VowelCount(Sentence)
Console.ReadLine()
End Sub
Sub WordCount(ByVal UserInput As String)
Dim Space As String() = UserInput.Split(" ")
Console.WriteLine("There are {0} words", Space.Length)
End Sub
Sub VowelCount(ByVal UserInput As String)
Dim i As Integer
Dim VowelNumber As Integer
Dim Vowels As String = "aeiou"
For i = 1 To Len(UserInput)
If InStr(Vowels, Mid(UserInput, i, 1)) Then
VowelNumber = VowelNumber + 1
End If
Next
Console.WriteLine("There are {0} vowels", VowelNumber)
End Sub
Thanks for your time
I would use the following three functions. Note that WordCount uses RemoveEmptyEntries avoids counting empty words when there are multiple spaces between words.
The other two functions count upper case vowels as vowels, rather than just lower case. They take advantage of the fact that strings can be treated as arrays of Char, and use the Count method to count how many of those Chars meet certain criteria.
Note that the designation of "AEIOU" as vowels may not be correct in all languages, and even in English "Y" is sometimes considered a vowel. You might also need to consider the possibility of accented letters such as "É".
Function WordCount(UserInput As String) As Integer
Return UserInput.Split({" "c}, StringSplitOptions.RemoveEmptyEntries).Length
End Function
Function VowelCount(UserInput As String) As Integer
Return UserInput.Count(Function(c) "aeiouAEIOU".Contains(c))
End Function
Function ConsonantCount(UserInput As String) As Integer
Return UserInput.Count(Function(c) Char.IsLetter(c) And Not "aeiouAEIOU".Contains(c))
End Function
To turn each of your Sub routines into a Function, you need to do three things. First, you need to change the Sub and End Sub keywords to Function and End Function, respectively. So:
Sub MyMethod(input As String)
' ...
End Sub
Becomes:
Function MyMethod(input As String)
' ...
End Function
Next, since it's a function, it needs to return a value, so your Function declaration needs to specify the type of the return value. So, the above example would become:
Function MyMethod(input As String) As Integer
' ...
End Function
Finally, the code in the function must actually specify what the return value will be. In VB.NET, that is accomplished by using the Return keyword, like this:
Function MyMethod(input As String) As Integer
Dim result As Integer
' ...
Return result
End Function
So, to apply that to your example:
Sub WordCount(ByVal UserInput As String)
Dim Space As String() = UserInput.Split(" ")
Console.WriteLine("There are {0} words", Space.Length)
End Sub
Would become:
Function WordCount(userInput As String) As Integer
Dim Space As String() = UserInput.Split(" ")
Return Space.Length
End Sub
Note, ByVal is the default, so you don't need to specify it, and parameter variables, by standard convention in .NET are supposed to be camelCase rather than PascalCase. Then, when you call the method, you can use the return value of the function like this:
Dim count As Integer = WordCount(Sentence)
Console.WriteLine("There are {0} words", count)
As far as counting consonants goes, that will be very similar to your VowelCount method, except that you would give it the list of consonants to look for instead of vowels.
You could use the Regex class. It's designed to search for substrings using patterns, and it's rather fast at it too.
Sub VowelCount(ByVal UserInput As String)
Console.WriteLine("There are {0} vowels", System.Text.RegularExpressions.Regex.Matches(UserInput, "[aeiou]", System.Text.RegularExpressions.RegexOptions.IgnoreCase).Count.ToString())
End Sub
[aeiou] is the pattern used when performing the search. It matches any of the characters you've written inside the brackets.
Example:
http://ideone.com/LEYC30
Read more about Regex:
MSDN - .NET Framework Regular Expressions
MSDN - Regular Expression Language - Quick Reference
VB is no longer a language I use frequently but I don't think I'm going to steer you wrong even without testing this out.
Sub Main()
Dim Sentence As String
Console.WriteLine("Sentence Analysis" + vbNewLine + "")
Console.WriteLine("Enter a sentence, then press 'Enter'" + vbNewLine + "")
Sentence = Console.ReadLine()
Console.WriteLine("")
'usually it's better just let the function calculate a value and do output elsewhere
'so I've commented your original calls so you can see where they used to be
'Call WordCount(Sentence)
Console.WriteLine("There are {0} words", WordCount(Sentence))
'Call VowelCount(Sentence)
Console.WriteLine("There are {0} vowels", VowelCount(Sentence))
Console.ReadLine()
End Sub
Function WordCount(ByVal UserInput As String) As Integer
Dim Space As String() = UserInput.Split(" ")
WordCount = Space.Length
'or just shorten it to one line...
'Return UserInput.Split(" ").Length
End Function
Function VowelCount(ByVal UserInput As String) As Integer
Dim i As Integer
Dim VowelNumber As Integer
Dim Vowels As String = "aeiou"
For i = 1 To Len(UserInput)
If InStr(Vowels, Mid(UserInput, i, 1)) Then
VowelNumber = VowelNumber + 1
End If
Next
VowelCount = VowelNumber
End Function
The most obvious change between a sub and a function is changing the keywords that wrap up the procedure. For this conversation let's just say that's one good word to use for encompassing both concepts since they're very similar and many languages don't really draw such a big distinction.
For Visual Basic's purposes a function needs to return something and that's indicated by the As Integer that I added to the end of both of the function declarations (can't remember if that's the right VB terminology.) Also in VB you return a value to the caller by assigning to the name of the function (also see edit below.) So I replaced those lines that were WriteLines with appropriate assignments. Last I moved those WriteLine statements up into Main. The arguments needed to be changed to use the function return values rather than the variables they originally referenced.
Hopefully I'm not doing your homework for you!
EDIT: Visual Basic underwent a lot of changes to the language during the move to .Net back in the early 2000's. I had forgotten (or possibly not even realized) that the new preferred choice for returning a value is now more in line with languages like C#. So rather than assigning values to WordCount and VowelCount you can just use Return. One difference between the two is that a Return will cause the sub/function to exit at that point even if there is other code afterward. This might be useful inside an if...end if for example. I'm hoping this helps you learn something rather than just being confusing.
EDIT #2: Now that I see the accepted answer and re-read the question it seems there was a small part about counting consonants that got overlooked. At this point I assume this was indeed a classroom exercise and the intended answer was possibly even to derive the consonant count by using the other functions.
Here you go.
Function WordCount(ByVal UserInput As String) As Integer
Dim Space As String() = UserInput.Split(" ")
Return Space.Length
End Function
Function VowelCount(ByVal UserInput As String) As Integer
Dim i As Integer
Dim VowelNumber As Integer
Dim Vowels As String = "aeiou"
For i = 1 To Len(UserInput)
If InStr(Vowels, Mid(UserInput, i, 1)) Then
VowelNumber = VowelNumber + 1
End If
Next
Return VowelNumber
End Function
Function ConsonantCount(ByVal UserInput As String) As Integer
Dim i As Integer
Dim ConsonantNumber As Integer
Dim Consonants As String = "bcdfghjklmnpqrstvwxyz"
For i = 1 To Len(UserInput)
If InStr(Consonants, Mid(UserInput, i, 1)) Then
ConsonantNumber = ConsonantNumber + 1
End If
Next
Return ConsonantNumber
End Function
I'm making a player-match-up program in Visual Basic. The program is supposed to pick random registered players and and pair them. I'm currently working on the odd-number-of-players-part.
The solution I have is working but is perhaps not that effective. Is there a better way for me to write this code?
The code is supposed to pick the random players and make sure they are not picked again. As you see, for the code to work i must make it loop thousands of times. If I don't some of the players won't show up in the listbox. Is there a better solution???
In case it's confusing "spiller" is norwegian for "player"
For i As Integer = 0 To 100000
Dim spiller1 As Integer
Dim spiller2 As Integer
Do
spiller1 = CInt(Math.Floor(Rnd() * spillerListe.Count))
spiller2 = CInt(Math.Floor(Rnd() * spillerListe.Count))
Loop Until CBool(spiller1 <> spiller2)
If brukteSpillere(spiller1) = False And brukteSpillere(spiller2) = False Then
brukteSpillere(spiller1) = True
brukteSpillere(spiller2) = True
lstSpillere.Items.Add(spillerListe(spiller1).ToString + " VS. " + spillerListe(spiller2).ToString())
End If
Next i
This is a mess... Have a List(Of Integer) with all the available index.
Loop while availableIndex.Count > 1
Pick a random index from availableIndex and remove it from that list
Pick a random index from availableIndex and remove it from that list
Add these two index to the list of pairs
End Loop
that way you don't need to check if the random values are the same or if they were already picked.
Now, if you don't want to create a list. Then threat the random number not as an index, but as the number of items to check.
Delta = RandomNumber
x = 0
For i As Integer = 0 To itemList.Count-1
If Not itemList(i).IsChoosen Then
x += 1
If x = Delta Then
' i is now your item to pick
itemList(i).IsChoosen = True
Exit For
End If
End If
Next
There are two efficient ways in approaching this problem:
Sort your player list by random number, then match up 1 with 2, 3 with 4 and so on.
Dim r As New Random
Dim randomListe = spillerListe.OrderBy(Function() r.Next).ToList
Generate two random numbers from your range, match up those players into a separate List, remove players from the original list. General two more random numbers from a smaller range (original minus 2), match up, etc.
EDIT: Having looked at MSDN, List has O(n) performance for RemoveAt, so it's not quite efficient, better be using a dictionary, which is O(1) at removing items, so instead of spillerListe have some spillerDicte, where you would add entries in a form (key = index, value = item).
Instead of working with integers, what if you keep your players name in a list and, after picking a player you remove it from the list. Probably this will not be the best performant solution, but it is clear what are you trying to do
Dim lstSpillere = new List(Of String)() ' Just for the example below
Dim spillerListe = new List(Of String)() from {"Marc", "John", "Steve", "George", "David", "Jeremy", "Andrew" }
Dim rnd = new Random()
While spillerListe.Count > 1
Dim firstPlayer = spillerListe(rnd.Next(0, spillerListe.Count))
spillerListe.Remove(firstPlayer)
Dim secondPlayer = spillerListe(rnd.Next(0, spillerListe.Count))
spillerListe.Remove(secondPlayer)
lstSpillere.Add(firstPlayer + " VS. " + secondPlayer)
' for debug purpose....
Console.WriteLine(firstPlayer & " VS. " & secondPlayer)
End While
if spillerListe.Count > 0 Then
Console.WriteLine("Excluded from play list is:" & spillerListe(0))
End if
The important key here is the generation of Random instance that should be outside the loop to avoid to generate the same number in the short time period required by the loop to execute.
Try this:
Module Module1
Dim rnd As New Random
Sub Main()
Dim RegisteredPlayers As New List(Of Player)
' Fill List (example 100 players)
For index As Integer = 1 To 100
RegisteredPlayers.Add(New Player(String.Format("Player{0}", index)))
Next
'Sort Players using a random number
Dim SortedPlayersArray = RandomSortItems(RegisteredPlayers.ToArray())
'Pair players by selecting 2 consequative ones from randomly sorted array
Dim Matches As New List(Of Match)
For index As Integer = 1 To SortedPlayersArray.Length Step 2
Dim m As Match = New Match(SortedPlayersArray(index - 1), SortedPlayersArray(index))
Matches.Add(m)
Debug.WriteLine(m.ToString())
Next
' Match Player48 vs. Player79
' Match Player3 vs. Player53
' Match Player18 vs. Player43
' Match Player85 vs. Player1
' Match Player47 vs. Player56
' Match Player23 vs. Player66
' etc..
End Sub
Public Function RandomSortItems(Of T)(ByVal items As T()) As T()
Dim sorted As T() = New T(items.Length-1) {}
Array.Copy(items, sorted, sorted.Length)
Dim keys As Double() = New Double(items.Length-1) {}
For i As Integer = 1 To items.Length
keys(i - 1) = rnd.NextDouble()
Next
Array.Sort(keys, sorted)
Return sorted
End Function
End Module1
Public Class Player
Dim m_name As String
Public Sub New(ByVal player_name As String)
m_name = player_name
End Sub
Public ReadOnly Property Name() As String
Get
Return m_name
End Get
End Property
Public Overrides Function ToString() As String
Return m_name
End Function
End Class
Public Class Match
Dim m_player_1 As Player, m_player_2 As Player
Public Sub New(ByVal player_1 As Player, ByVal player_2 As Player)
m_player_1 = player_1
m_player_2 = player_2
End Sub
Public ReadOnly Property Player1() As Player
Get
Return m_player_1
End Get
End Property
Public ReadOnly Property Player2() As Player
Get
Return m_player_2
End Get
End Property
Public Overrides Function ToString() As String
Return String.Format("Match {0} vs. {1}", Player1, Player2)
End Function
End Class
Edit 1:
An alternate random sorter (which should be faster) is
Public Function RandomSortItems(Of T)(ByVal items As T()) As T()
Dim slist As New SortedList(Of Double, T)
For i As Integer = 1 to items.Length
slist.Add(rnd.NextDouble(), items(i-1) )
Next i
return slist.Values.ToArray()
End Function
We perform a protocol based data sending to device where the device requires a formatted data packets.
the sample packet data is XXFSXXXFSXXXXXXXFSXXXXXX. The X mentioned is the max length size of each string. if data is less than string max length it should be filled with NULL character like ..11FS123FS1234XXXX (the remaining X will be filled with NULL).
I am just trying to convert one of VB6 function to VB.Net and below is the converted statement where i am facing issue
Option Strict Off
Option Explicit On
Imports Microsoft.VisualBasic.Compatibility.VB6
Imports System
Imports System.Runtime.InteropServices
Module FunctionCmd_Msg
Public FunCommand_Msg As Fun_CommandMessage = Fun_CommandMessage.CreateInstance()
'Function Command Message
<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Auto)> _ _
Public Structure Fun_CommandMessage
<VBFixedString(1)> Public one As String
<VBFixedString(1)> Public two As String
<VBFixedString(3)> Public three As String
Dim five As String
<VBFixedString(8)> Public four As String
Public Shared Function CreateInstance() As Fun_CommandMessage
Dim result As New Fun_CommandMessage
result.one = String.Empty
result.two = String.Empty
result.three = String.Empty
result.four = String.Empty
result.five = String.Empty
End Function
End Structure
End Module
assuming:
one = "1"
two = "1"
three = "123"
four = "5678"
five = "testing"
FS = character (field separator)
on concatenating the strings i need a fixed length string such like this:
one & two & FS & three & FS & five & FS & four
output: since four is a fixed length string of 8 length remaining 4 characters should be filled with null as below
11 FS 123 FS testing FS 5678XXXX
Fixed-length strings simply make no sense in .NET any more. Microsoft tried to provide a similar class for easier upgrade but the truth is that you should change your code depending on usage:
What did the fixed-length string do in your VB6 code? Was it for no good reason? Then use a normal String in .NET.
Was it for interop with a C API? Then use marshalling to set a size for an array in the C API call.
Just forget about the fixed length, and use regular vb.net strings. They will return fine to whatever calls that code, including interop.
So, just pad your strings, and you off to the races.
In fact, build a Msg class that does the dirty work for you.
This looks quite nice to me:
NOTE how I set this up that you ONLY define the length of the string in ONE place. (so I use len(m_string) to determine the length from THEN on in the code.
Also, for debug and this example, in place of vbcharNull (which you should use), I used X for testing.
Now, in your code?
Just use this:
Dim Msg As New MyMsg
With Msg
.one = "A"
.two = "B"
.three = "C"
.four = "D"
.Five = "E"
End With
Debug.WriteLine(Msg.Msg("*") & vbCrLf)
Debug.WriteLine("total lenght = " & Len(Msg.Msg("X").ToString))
Output:
A*B*CXX*EXXXXXXX*DXXXXXXX
total lenght = 25
I note in your code that you have FIVE before FOUR - but if that is what you want, then no problem
Note that the class ALWAYS maintains the lengths for you.
So just paste this code into your module or even a new separate class.
Public Class MyMsg
'Dim cPad As Char = vbNullChar
Dim cPad As Char = "X"
Private m_one As String = New String(cPad, 1)
Private m_two As String = New String(cPad, 1)
Private m_three As String = New String(cPad, 3)
Private m_four As String = New String(cPad, 8)
Private m_five As String = New String(cPad, 8)
Public Property one As String
Get
Return m_one
End Get
Set(value As String)
m_one = MyPad(value, m_one)
End Set
End Property
Public Property two As String
Get
Return m_two
End Get
Set(value As String)
m_two = MyPad(value, m_two)
End Set
End Property
Public Property three As String
Get
Return m_three
End Get
Set(value As String)
m_three = MyPad(value, m_three)
End Set
End Property
Public Property four As String
Get
Return m_four
End Get
Set(value As String)
m_four = MyPad(value, m_four)
End Set
End Property
Public Property Five As String
Get
Return m_five
End Get
Set(value As String)
m_five = MyPad(value, m_five)
End Set
End Property
Public Function Msg(FS As String) As String
Return m_one & FS & m_two & FS & m_three & FS & m_five & FS & m_four
End Function
Private Function MyPad(str As String, strV As String) As String
Return Strings.Left(str & New String(Me.cPad, Len(strV)), Len(strV))
End Function
End Class
As noted, change the commented out line of "X" for the char back to vbCharNull.
And of course you STILL get to choose the delimiter. I used
Msg.Msg("*")
so I used a "*", but you can use space, or anything you want.