Validating UTF32->ASCII - vb.net

I'm making a program that draws text from a spreadsheet and then pastes it into a .txt file. The problem I've found is that if the character isn't a valid ASCII one it's replaced by characters ranging from ? to ^ or superscript numbers.
I know this is because these characters aren't ASCII supported, but how could I check and swap them out? Is there a list of non-ascii supported characters I can use, or a function that checks validity?
Thanks

ASCII characters have values from 0 to 127, so you could use the AscW function:
If AscW(inputChar) > 127 then
outputChar = "*"c
Else
outputChar = inputChar
End If
' now write outputChar

its' more the other way around. there is no such thing like ASCII support. What you could do is give your textfile a UTF32-BOM first, then your texteditor can interpret the numbers it reads and has the possibility to show the right characters.
see wikipedia "Byte Order Mark".
Edit after discussion:
if you only need 7-bit ASCII and nothing else, use either Encoding.ASCII or Andrews approach.
otherwise you could use ASCIIEncoding.GetEncoding(yourcodepage)
Dim thisText As String = "ÄÖÜäöü" & " Pi: " & ChrW(&H3A0) & " Sigma: " & ChrW(&H3A3)
Dim fileOut As String = Environment.GetFolderPath(Environment.SpecialFolder.Desktop)
Dim enc_ascii As System.Text.Encoding
enc_ascii = System.Text.Encoding.ASCII '7-bit
Using output As New StreamWriter(New FileStream(fileOut & "\test1.txt", FileMode.Create), enc_ascii)
output.Write(thisText)
End Using
enc_ascii = System.Text.ASCIIEncoding.GetEncoding(1250) 'central europe
Using output As New StreamWriter(New FileStream(fileOut & "\test2.txt", FileMode.Create), enc_ascii)
output.Write(thisText)
End Using
enc_ascii = System.Text.ASCIIEncoding.GetEncoding(1253) 'greek
Using output As New StreamWriter(New FileStream(fileOut & "\test3.txt", FileMode.Create), enc_ascii)
output.Write(thisText)
End Using

Related

String Concatenation with Comma and Single Quotes E.g. ('ABC','DEF','GHI,'JKL')

I've been searching on internet how to Concatenate/Join Single quotes and comma on the String in vb.net's RichTextBox control. Example ('ABC','DEF','GHI,'JKL') I found this code online today it works even there's leading and trailing spaces and even lines are removed but the (' and ') are missing. Can you guys modify the code?
Code:
RichTextBox1.Text = Regex.Replace(RichTextBox1.Text.Trim, "\s+", "','")
Inside the RichTextBox1
ABC
DEF
GHI
JKL
Result: ABC','DEF','GHI','JKL
Desired Result: ('ABC','DEF','GHI','JKL')
As you can see, there are multiple ways this could be done. Here's another:
myRichTextBox.Text = $"('{String.Join("'," & ControlsChars.Lf & "'", myRichTextBox.Lines)}')"
Note that I have used ControlChars.Lf where I would usually use Environment.NewLine because the RichTextBox always uses that line break. I assume that it has something to do with the RTF format and compatibility.
Give this a try
' starting RichTextBox1 contains
' ABC
' DEF
' GHI
' JKL
Dim lns() As String = RichTextBox1.Lines
For x As Integer = 0 To lns.Length - 1
lns(x) = String.Format("'{0}',", lns(x))
Next
lns(0) = "(" & lns(0)
lns(lns.Length - 1) = lns(lns.Length - 1).TrimEnd(","c)
lns(lns.Length - 1) &= ")"
RichTextBox1.Lines = lns
Not knowing how many lines you are dealing with in a real scenario, I chose to use a StringBuilder. It creates mutable (changeable) strings saving us throwing away and recreating strings many times.
Start off the sb with the initial "(". Then the loop uses an interpolated string with an embedded variable for each line. AppendLine will add a new line after the text.
Lastly we display the new string. In .net we can string the dot notation working left to right. First convert the StringBuilder back to an actual String with .ToString. Next we clean up the end of the new string by removing the final comma and the final new line. A new line is actually composed of 2 Chars, carriage return and line feed. Lastly I added the final ")"
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim lines() = File.ReadAllLines("some text file path")
Dim sb As New StringBuilder
sb.Append("(")
For Each line In lines
sb.AppendLine($"'{line}',")
Next
RichTextBox1.Text = sb.ToString.Trim({","c, Convert.ToChar(13), Convert.ToChar(10)}) & ")"
End Sub

How to replace a character within a string

I'm trying to convert WText into its ASCII code and put it into a TextBox; Numencrypt. But I don't want to convert the spaces into ASCII code.
How do I replace the spaces with null?
Current code:
Dim withSpace As String = Numencrypt.Text
For h = 1 To lenText
wASC = wASC & CStr(Asc(Mid$(WText, h, 1)))
Next h
Numencrypt.Text = wASC
Numencrypt2.Text = Numencrypt2.Replace(Numencrypt.Text, " ", "")
By the way, the TextBox Numencrypt2 is the WText without a space inside it.
Without knowing whether or not you want the null character or empty string I did the following in a console app so I don't have your variables. I also used a string builder to make the string concatenation more performant.
Dim withSpaces = "This has some spaces in it!"
withSpaces = withSpaces.Replace(" "c, ControlChars.NullChar)
Dim wASC As New StringBuilder
For h = 1 To withSpaces.Length
wASC.Append($"{AscW(Mid(withSpaces, h, 1))} ") ' Added a space so you can see the boundaries ascii code boundaries.
Next
Dim theResult = wASC.ToString()
Console.WriteLine(theResult)
You will find that if you use ControlChars.NewLine as I have, the place you had spaces will be represented by a zero. That position is completely ignored if you use Replace(" ", "")

Removing CR/LF at end of file in VB.net

I've searched for a solution to this, but any I've found are either doing much more than I need or are not exactly what I want.
I have files I want to append to. I need to append to the end of the last line but they all have a carriage return and so I'll end up appending to the new line if I just append as normal.
All I want is to make a subroutine that takes a file path and removes the CR/LF at the end of it, no more, no less. Any help pointing me at a solution to this would be appreciated. I'm surprised there isn't a built in function to do this.
Dim crString = Environment.NewLine '= vbCrLf
Dim crBytes = Encoding.UTF8.GetBytes(crString)
Dim bytesRead(crBytes.Length - 1) as Byte
Dim iOffset As Integer = 0
Dim stringRead As String
Using fs = File.Open("G:\test.txt", FileMode.Open, FileAccess.ReadWrite)
While iOffset < fs.Length
fs.Seek(- (crBytes.Length + iOffset), SeekOrigin.End)
fs.Read(bytesRead,0, crBytes.Length)
stringRead = Encoding.UTF8.GetString(bytesRead)
If stringRead = crString Then
fs.SetLength(fs.Length - (crBytes.Length * iOffset + 1))
Exit While
End If
iOffset += 1
End While
End Using
I open the text file as FileStream and set its position to the end of the file - length of the carriage return string.
I then read the current bytes while decreasing the offset until I found a carriage return or the eof has been reached.
If a CR has been found I remove it and everything what comes after.
If you don´t want that just remove the loop and check the eof only.
But there could be some vbNullString at the eof that´s why I´m using the loop.
Please note that I used UTF8 encoding in my example. If you have other encodings you have to adapt it accordingly.
test.txt before run:
test.txt after code snippet run:
EDIT: fs.SetLength part was wrong in case of last character in file was not a CR.
I have found String.Replace(ControlChars.CrLf.ToCharArray(),"") works.
Probably better ways to do it as well!

Get only the line of text that contains the given word VB2010.net

I have a text file on my website and I download the whole string via webclient.downloadstring.
The text file contains this :
cookies,dishes,candy,(new line)
back,forward,refresh,(new line)
mail,media,mute,
This is just an example it's not the actual string , but it will do for help purposes.
What I want is I want to download the whole string , find the line that contains the word that was entered by the user in a textbox, get that line into a string, then I want to use the string.split with as delimiter the "," and output each word that is in the string into an richtextbox.
Now here is the code that I have used (some fields are removed for privacy reasons).
If TextBox1.TextLength > 0 Then
words = web.DownloadString("webadress here")
If words.Contains(TextBox1.Text) Then
'retrieval code here
Dim length As Integer = TextBox1.TextLength
Dim word As String
word = words.Substring(length + 1) // the plus 1 is for the ","
Dim cred() As String
cred = word.Split(",")
RichTextBox1.Text = "Your word: " + cred(0) + vbCr + "Your other word: " + cred(1)
Else
MsgBox("Sorry, but we could not find the word you have entered", MsgBoxStyle.Critical)
End If
Else
MsgBox("Please fill in an word", MsgBoxStyle.Critical)
End If
Now it works and no errors , but it only works for line 1 and not on line 2 or 3
what am I doing wrong ?
It's because the string words also contains the new line characters that you seem to be omitting in your code. You should first split words with the delimiter \n (or \r\n, depending on the platform), like this:
Dim lines() As String = words.Split("\n")
After that, you have an array of strings, each element representing a single line. Loop it through like this:
For Each line As String In lines
If line.Contains(TextBox1.Text) Then
'retrieval code here
End If
Next
Smi's answer is correct, but since you're using VB you need to split on vbNewLine. \n and \r are for use in C#. I get tripped up by that a lot.
Another way to do this is to use regular expressions. A regular expression match can both find the word you want and return the line that contains it in a single step.
Barely tested sample below. I couldn't quite figure out if your code was doing what you said it should be doing so I improvised based on your description.
Imports System.Text.RegularExpressions
Public Class Form1
Private Sub ButtonFind_Click(sender As System.Object, e As System.EventArgs) Handles ButtonFind.Click
Dim downloadedString As String
downloadedString = "cookies,dishes,candy," _
& vbNewLine & "back,forward,refresh," _
& vbNewLine & "mail,media,mute,"
'Use the regular expression anchor characters (^$) to match a line that contains the given text.
Dim wordToFind As String = TextBox1.Text & "," 'Include the comma that comes after each word to avoid partial matches.
Dim pattern As String = "^.*" & wordToFind & ".*$"
Dim rx As Regex = New Regex(pattern, RegexOptions.Multiline + RegexOptions.IgnoreCase)
Dim M As Match = rx.Match(downloadedString)
'M will either be Match.Empty (no matching word was found),
'or it will be the matching line.
If M IsNot Match.Empty Then
Dim words() As String = M.Value.Split(","c)
RichTextBox1.Clear()
For Each word As String In words
If Not String.IsNullOrEmpty(word) Then
RichTextBox1.AppendText(word & vbNewLine)
End If
Next
Else
RichTextBox1.Text = "No match found."
End If
End Sub
End Class

modifying/ getting rid of characters in text from txt file ussing vb.net

I have a string of text i captured within AutoCAD (0.000000, 0.000000, 0.000000) wich is saved to a text based file named position.txt.
as you probably have gatherd with a file name such as position.txt the text could be composed of any random number combination eg: (5.745379, 0.846290, 150.6459046).
However for it to be of any use to me I need the captured string to exist without spaces or brackets how can i achiev this in VB.net?
Use String.Replace. Its probably not the most efficient way but it will get the job done.
Dim file as String = My.Computer.FileSystem.ReadAllText("position.txt")
Dim output as String = file.Replace(" ", "") _
.Replace("(", "") _
.Replace(")", "")
My.Computer.FileSystem.WriteAllText("output.txt", output, false)
as above
s = "(5.745379, 0.846290, 150.6459046)"
s = s.replace("(","")
s = s.replace(")","")
and then
dim answer() as string = s.split(",")
dim number as double
For each a as string in answer
if double.tryparse(a,n) then
console.writeline(n.tostring & " is a number")
else
console.writeline(n.tostring & " is rubbish")
next