start=AKS-RHzlSXSftLGYdBNk.eyJhbGdvcml0aG0iOiJITUFDLVNIQTI1&
For every instance of the word 'start' I need to be able to get the text after the first full stop, right up until the & symbol. E.g. 'eyJhbGdvcml0aG0iOiJITUFDLVNIQTI1'.
There will be more than one instance of this. They will need to be appended to a listbox.
What is the simplest/quickest way to do this? (Using possibly streamreader - text file)
The simplest and quickest way will be to read each line, and check if it .StartsWith("start="). If so, then get the .IndexOf(".") and the .IndexOf("&", <whereever the first indexOf was>). Get the .SubString which encompasses those two values. I'm sure you can write the code yourself from that ;)
I tested this function with a button click, output text each line on a textbox. I am sure you can adapt this to your code.
Private Sub Button_Click(sender As Object, e As RoutedEventArgs)
txtResults.Text = ""
Dim ParseString As String
ParseString = "start=123341.23124&kjdshfkjsdaksdstart=1231.2321312&kadhskjashdkjastart=1231.23126789898&skjdfhkjsd"
Dim Delimiters() As String = New String() {"start="}
Dim Words() As String
Words = ParseString.Split(Delimiters, CompareMethod.Text)
For Each Part In Words
Dim Middle As String
Middle = Part.Split(".").Skip(1).Take(1).FirstOrDefault()
Dim Good As String
Good = Middle.Split("&").FirstOrDefault()
txtResults.Text += Good + vbNewLine
Next
End Sub
Output was
23124
2321312
23126789898
Added 31104 lines to a string and ran, took about 11 seconds to run on my laptop. Might be too slow for your app?
Related
I need to extract text from a text file starting with the order number(eg. Order1) and ending with an empty line with all other lines between the order number and the empty line extracted as well for a query. Really have no idea how to go about this so any help is greatly appreciated!
so the file name is "CustomerDetails.txt" and I'd imagine the code would look something like this
If IO.File.Exists("CustomerDetails.txt") Then
Dim inFile As IO.StreamReader = IO.File.OpenText(“CustomerDetails.txt")
End If
and then taking for example "order1" in that text file until the blank space and displaying that is a list box
"Really have no idea how to go about this "
The thinking could go like this...
A text file has a string in it.
I could look up the String class in .net and see if there are any methods that could help me.
Search for "String class in .net"
Looks like we can use a combination of String.IndexOf(String, Int32) and String.Substring(Int32, Int32)
Find the IndexOf your order. The string will be the order "Order1" and we will start looking at index 0 so the Int32 will be 0. Then find the end index. Start looking at the index we just found and stop at the first blank line. We can get the length required by the `.Substring method by subtracting the start index from the end index. Now we can extract the text of Order 1 with the substring method.
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim OrderText As String = "Order 1" 'this could be set with TextBox1.Text
'Get the string out of the file
Dim s As String = File.ReadAllText("CustomerDetails.txt")
'Find the index of the order, this overload assumes start index is 0
Dim startIndex As Integer = s.IndexOf(OrderText) 'starts lookint at beginning
'Find the index of the first blank line after the startIndex
'2 new lines make a bland line
Dim endIndex As Integer = s.IndexOf(Environment.NewLine & Environment.NewLine, startIndex)
'Return the string that stars at startIndex with a length of end minus start
Dim Order As String = s.Substring(startIndex, endIndex - startIndex)
'I am going to guess that the details of the order are on separate lines
Dim lines() As String = Order.Split(New String() {Environment.NewLine}, StringSplitOptions.None)
For Each line As String In lines
ListBox1.Items.Add(line)
Next
End Sub
I have in a text file lines of this format:
word1|word2|word3
anotherword1|anotherword2
I'm trying to split each word one by one per every line of that file and once program detect if the richtextbox has one of these words will replace that word with the unsplitted line. Example: From word1 to word1|word2|word3
Here is what I have so far:
Private Sub Button1_Click_1(sender As Object, e As EventArgs) Handles Button1.Click
For Each line As String In File.ReadLines("C:\text.txt")
Dim input As String = line
Dim result As String() = line.Split(New String() {"|"}, StringSplitOptions.None)
For Each s As String In result
Try
Dim linex As String = line
RichTextBox1.Text = RichTextBox1.Text.Replace(s, " " & linex)
Catch exxx As Exception
End Try
Next
Next
End Sub
It works great, but after the replacement, the replaced text still have the detected word and it keep replacing itself with word1|word2|word3 forever. And I want do do the process just once.
Like this: Click to see
Due to the format the words are stored in, it will be much easier to achieve what you want using Regular Expressions:
Dim lines = File.ReadLines("C:\text.txt")
For Each line As String In lines
Dim pat = String.Format("\b({0})\b", line)
RichTextBox1.Text = Regex.Replace(RichTextBox1.Text, pat, line)
Next
This should do pretty much what you want.
Check it here.
I'm using Visual studio to build a small utility.
I'm importing variables from a text file (this makes my program expandable in the future).
I'm running into a road block trying to split the variables into usable parts.
The text file is set up as such:
Game1:flshflhdlsfsdsfs
Game2:ugdjgndrgbdvdnjd
Game3:gnnereknengievke
And the code I've gathered from searching around trying to understand how I could do this is (It's gone through multiple rewrites but I feel this is probably the closest I've gotten):
Dim value As String = File.ReadAllText("Games.txt")
Dim cut_at As String = ":"
Dim x As Integer = InStr(value, cut_at)
Dim string_before As String = value.Substring(0, x - 2)
Dim string_after As String = value.Substring(x + cut_at.Length - 1)
Games_drp.Items.AddRange(string_before)
When I run a test like this, I get an error that String_before cannot be converted to an object. I tried switching "Dim string_before As String = value.Substring(0, x - 2)" to Dim string_before As Object = value.Substring(0, x - 2), but the dropdown that's supposed to be populated by at least one of the entries before the : has absolutely nothing in it.
Being pretty new at VB and feeling like I've exhausted pretty much every way I could think of searching in google and trying to piece together various bits of information, I figure I'd try asking my own direct question:
How would I go about reading all the lines from a text file, then splitting before the : to fill a combobox, and using a label to display the string after the : matching which ever entry is selected in the dropdown.
Thanks in advance for any help.
EDIT with full code:
Imports System.IO
Public Class Saves_frm
Private Sub Saves_frm_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim value As String = File.ReadAllText("Games.txt")
Dim cut_at As String = ":"
Dim x As Integer = InStr(value, cut_at)
Dim string_before As String = value.Substring(0, x - 2)
Dim string_after As String = value.Substring(x + cut_at.Length - 1)
Games_drp.Items.AddRange(string_before)
End Sub
End Class
When run as is, I get an error that 'string_before' can't be converted from a string to an object, but when I make the following change from:
Dim string_before As String = value.Substring(0, x - 2)
to:
Dim string_before As Object = value.Substring(0, x - 2)
The error goes away, but the dropdown remains blank.
It's easier to use File.ReadAllLines, as it returns an array with all the file's lines. Then, you can loop through the lines, splitting each line and adding the result to the ListBox. This should be an example, but feel free to correct any mistakes I made, as I wrote it on my phone and it's been a long time since I used VB.
Dim lines() As String = File.ReadAllLines("file.txt")
For Each line As String In lines
Dim split() As String = line.Split(":"c)
gDic.Add(split(0), split(1))
Next
EDIT: Then, you most certainly want a dictionary that contains the name and the data, check the updated code.
Then, add the names by looping through gDic.Keys. When a name is selected, access its value with gDic("key").
Does anybody know how to lowercase the first word for each line in a textbox?
Not the first letter, the first word.
I tried like this but it doesn't work:
For Each iz As String In txtCode.Text.Substring(0, txtCode.Text.IndexOf(" "))
iz = LCase(iz)
Next
When you call Substring, it is making a copy of that portion of the string and returning it as a new string object. So, even if you were successfully changing the value of that returned sub-string, it still would not change the original string in the Text property.
However, strings in .NET are immutable reference-types, so when you set iz = ... all you are doing is re-assigning the iz variable to point to yet another new string object. When you set iz, you aren't even touching the value of that copied sub-string to which it previously pointed.
In order to change the value of the text box, you must actually assign a new string value to its Text property, like this:
txtCode.Text = "the new value"
Since that is the case, I would recommend building a new string, using a StringBuilder object, and then, once the modified string is complete, then set the text box's Text property to that new string, for instance:
Dim builder As New StringBuilder()
For Each line As String In txtCode.Text.Split({Environment.NewLine}, StringSplitOptions.None)
' Fix case and append line to builder
Next
txtCode.Text = builder.ToString()
The solutions here are interesting but they are ignoring a fundamental tool of .NET: regular expressions. The solution can be written in one expression:
Dim result = Regex.Replace(txtCode.Text, "^\w+",
Function (match) match.Value.ToLower(), RegexOptions.Multiline)
(This requires the import System.Text.RegularExpressions.)
This solution is likely more efficient than all the other solutions here (It’s definitely more efficient than most), and it’s less code, thus less chance of a bug and easier to understand and to maintain.
The problem with your code is that you are running the loop only on each character of the first word in the whole TextBox text.
This code is looping over each line and takes the first word:
For Each line As String In txtCode.Text.Split(Environment.NewLine)
line = line.Trim().ToLower()
If line.IndexOf(" ") > 0 Then
line = line.Substring(0, line.IndexOf(" ")).Trim()
End If
// do something with 'line' here
Next
Loop through each of the lines of the textbox, splitting all of the words in the line, making sure to .ToLower() the first word:
Dim strResults As String = String.Empty
For Each strLine As String In IO.File.ReadAllText("C:\Test\StackFlow.txt").Split(ControlChars.NewLine)
Dim lstWords As List(Of String) = strLine.Split(" ").ToList()
If Not lstWords Is Nothing Then
strResults += lstWords(0).ToLower()
If lstWords.Count > 1 Then
For intCursor As Integer = 1 To (lstWords.Count - 1)
strResults += " " & lstWords(intCursor)
Next
End If
End If
Next
I used your ideas guys and i made it up to it like this:
For Each line As String In txtCode.Text.Split(Environment.NewLine)
Dim abc() As String = line.Split(" ")
txtCode.Text = txtCode.Text.Replace(abc(0), LCase(abc(0)))
Next
It works like this. Thank you all.
i am trying to split a string up into separate lines with the following code, but for some reason it is also removing the spaces in the string.
Dim calculationText As String
calculationText = File.ReadAllText(fileName)
Dim fields() As String
fields = calculationText.Split(vbCrLf)
when i am in debugger mode, i look at fields, and every element has a line of the string but all the spaces and tabs are removed.
any reason for this?
If you are reading from a file, can you use:
Sub Main()
Dim fields As New List(Of String)
' read file into list
Using sr As System.IO.StreamReader = My.Computer.FileSystem.OpenTextFileReader(filename)
Try
Do While sr.Peek() >= 0
fields.Add(sr.ReadLine())
Loop
Finally
If sr IsNot Nothing Then sr.Close()
End Try
End Using
' check results
For Each line As String In fields
Console.WriteLine(line)
Next
End Sub
How 'bout:
Dim fields() As String = File.ReadAllLines(fileName)
As for why string.Split() is doing weird things...
vbCrLf is a string, and there's not an overload for string.split that accepts a single string parameter. If he were to turn on Option Explicit it wouldn't even compile, but since it's off, vbCrLf can be interpreted as an array of characters. And in this code, that's exactly what happens:
Sub Main()
Dim z As String = "The quick brown" & vbCrLf & " fox jumps over the lazy dogs."
Dim a() As String = z.Split(vbCrLf)
For Each c As String In a
Console.WriteLine(c)
Next
Console.ReadKey(True)
End Sub
You'll see two line breaks between the 1st and 2nd parts of that string. Something else is stripping out the spaces. Can you share the larger code block?
Gotta say I've never seen it do that, and I've used String.Split extensively. Are they really really gone, or is it a trick of the debugger?
There's not actually any .Split method that takes one string as the parameter, so the VB compiler would be doing "things" behind the scenes to pick a different overload. To try and force the correct overload, you could try calculationText.Split(vbCrLf.ToCharArray()). I doubt it will help, but you never know :-)