How can I use this code?
TextBox1.Text = Array.FindIndex(linestring, Function(s) s.Contains(something))
but to use the code, without a word, and to display my array index following the code below:
Dim lines As New List(Of String)
Using reader As New StreamReader(My.Application.Info.DirectoryPath + ("\Data.txt"))
Dim line As String
Do Until line.StartsWith(endPrefix)
lines.Add(line)
line = reader.ReadLine()
'maybe here index of array
Loop
so how do I use this to get the line index from my text files?
Here is an example which uses the File.ReadLines method (which enumerates the lines of a file) where you can pass the predicate for the comparison to get the line number (starting at 1) of the first match:
Imports System.IO
Module Module1
Function FindLineNumber(sourceFile As String, textToFind As String, predicate As Func(Of String, String, Boolean)) As Integer
Dim lineNo = 1
For Each l In File.ReadLines(sourceFile)
If predicate(l, textToFind) Then
Return lineNo
End If
lineNo += 1
Next
Return -1
End Function
Sub Main()
' File to look in:
Dim src = "C:\temp\population.csv"
' Text to find:
Dim find = "133"
Dim lineNum = FindLineNumber(src, find, Function(a, b) a.Contains(b))
If lineNum > 0 Then
Console.WriteLine($"""{find}"" found at line {lineNum}.")
Else
Console.WriteLine($"""{find}"" not found.")
End If
Console.ReadLine()
End Sub
End Module
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
I have a comma delimited file with sample values :
1,1076103,22-NOV-16,21051169,50,1083,AAA,TEXT
Question : how to replace the comma in the last column which is "AAA,TEXT"
The result should be this way:
1,1076103,22-NOV-16,21051169,50,1083,AAATEXT
There is an overload of String.Split which takes an argument telling it the maximum number of parts to return. You could use it like this:
Option Infer On
Option Strict On
Module Module1
'TODO: think up a good name for this function
Function X(s As String) As String
Dim nReturnParts = 7
Dim parts = s.Split({","c}, nReturnParts)
If parts.Count < nReturnParts Then
Throw New ArgumentException($"Not enough parts - needs {nReturnParts}.")
End If
parts(nReturnParts - 1) = parts(nReturnParts - 1).Replace(",", "")
Return String.Join(",", parts)
End Function
Sub Main()
Dim s() = {"1,1076103,22-NOV-16,21051169,50,1083,AAA,TEXT",
"1,1076103,22-NOV-16,21051169,50,1083,BBBTEXT",
"1,1076103,22-NOV-16,21051169,50,1083,C,C,C,TEXT"}
For Each a In s
Console.WriteLine(X(a))
Next
Console.ReadLine()
End Sub
End Module
Outputs:
1,1076103,22-NOV-16,21051169,50,1083,AAATEXT
1,1076103,22-NOV-16,21051169,50,1083,BBBTEXT
1,1076103,22-NOV-16,21051169,50,1083,CCCTEXT
Is simple, but learn a bit how to use string ;)
Public Function MDP(strWork As String)
Dim splitted() As String = strWork.Split(","c)
Dim firsts As New List(Of String)
For i As Integer = 0 To splitted.Count - 3
firsts.Add(splitted(i))
Next
Dim result As String = System.String.Join(",", firsts)
Return result & "," & splitted(splitted.Count - 2) & splitted(splitted.Count - 1)
End Function
Then call with:
Dim finished As String = MDP("1,1076103,22-NOV-16,21051169,50,1083,AAA,TEXT")
I'm trying to count the number of an item in a text file, by counting each instance the item was entered into the file earlier on in the program.
I already have the text read from the file and in a text box. The problem is that my current code was just counting the characters in the textbox and not the number of times my desired word was in the file.
For Each desiredword As String In txtContentofFile.Text
intdesiredword = intdesiredword + 1
txtdesiredwordcount.Text = intdesiredword
Next
This counts the characters in the textbox instead of counting the number of desired words. I tried repeatedly before asking help and searched extensively, but I just don't understand what's wrong with my code. Please help :)
You can use Split Function :
C#:
int count = txtContentofFile.Text.Split(desiredword).Length - 1;
VB.net:
Dim count As Integer = txtContentofFile.Text.Split(desiredword).Length - 1
I prefer to use Regular Expressions in this type of situation. They are very tricky to understand but they are extremely powerful and typically faster than other string manipulation techniques.
Dim AllMatchResults As MatchCollection
Try
Dim RegexObj As New Regex(desiredword)
AllMatchResults = RegexObj.Matches(txtContentofFile.Text)
If AllMatchResults.Count > 0 Then
' Access individual matches using AllMatchResults.Item[]
Else
' Match attempt failed
End If
Catch ex As ArgumentException
'Syntax error in the regular expression
End Try
In your case you are looking for the value from AllMatchResults.Count.
Using a great Regular Expression tool like RegexBuddy to build and test the expressions is a great help too. (The above code snippet was generated by RegexBuddy!)
Try this:
Dim text As String = IO.File.ReadAllText("C:\file.txt")
Dim wordsToSearch() As String = New String() {"Hello", "World", "foo"}
Dim words As New List(Of String)()
Dim findings As Dictionary(Of String, List(Of Integer))
'Dividing into words
words.AddRange(text.Split(New String() {" ", Environment.NewLine()}, StringSplitOptions.RemoveEmptyEntries))
findings = SearchWords(words, wordsToSearch)
Console.WriteLine("Number of 'foo': " & findings("foo").Count)
Function used:
Private Function SearchWords(ByVal allWords As List(Of String), ByVal wordsToSearch() As String) As Dictionary(Of String, List(Of Integer))
Dim dResult As New Dictionary(Of String, List(Of Integer))()
Dim i As Integer = 0
For Each s As String In wordsToSearch
dResult.Add(s, New List(Of Integer))
While i >= 0 AndAlso i < allWords.Count
i = allWords.IndexOf(s, i)
If i >= 0 Then dResult(s).Add(i)
i += 1
End While
Next
Return dResult
End Function
You will have not only the number of occurances, but the index positions in the file, grouped easily in a Dictionary.
Try the following code
Function word_frequency(word_ As String, input As String) As Integer
Dim ct = 0
Try
Dim wLEN = word_.Length
Do While input.IndexOf(word_) <> -1
Dim idx = input.IndexOf(word_) + wLEN
ct += 1
input = input.Substring(idx)
Loop
Catch ex As Exception
End Try
Return ct
End Function
I have a string like
Query_1,ab563372363_C/R,100.00,249,0,0,1,249,1,249,1e-132, 460
Query_1,ab563372356_C/R,99.60,249,1,0,1,249,1,249,5e-131, 455
in a file
in two separate lines. I am reading it from the textbox. I have to output ab563372363_C/R and ab563372356_C/R in a text box. I am trying to use the split function for that but its not working..
Dim splitString as Array
results = "test.txt"
Dim FileText As String = IO.File.ReadAllText(results) 'reads the above contents from file
splitString = Split(FileText, ",", 14)
TextBox2.text = splitString(1) & splitString(13)
for the above code, it just prints the whole thing.. What's wrong?
Try this
Private Function GetRequiredText() As List(Of String)
Dim requiredStringList As New List(Of String)
Dim file = "test.txt"
If FileIO.FileSystem.FileExists(file) Then
Dim reader As System.IO.StreamReader = System.IO.File.OpenText(file)
Dim line As String = reader.ReadLine()
While line IsNot Nothing
requiredStringList.Add(line.Split(",")(1))
line = reader.ReadLine()
End While
reader.Close()
reader.Dispose()
End If
Return requiredStringList
End Function
This will read the file line by line and add the item you require to a list of strings which will be returned by the function.
Returning a List(Of String) may be overkill, but it's quite simple to illustrate and to work with.
You can then iterate through the list and do what you need with the contents of the list.
Comments welcome!!
Also this might work...
Dim query = From lines In System.IO.File.ReadAllLines(file) _
Select lines.Split(",")(1)
this will return an IEnumerable(Of String)
Enjoy
First
Since you are reading the whole text, your FileText would be ending like this:
Query_1,ab563372363_C/R,100.00,249,0,0,1,249,1,249,1e-132,460
\r\n
Query_1,ab563372356_C/R,99.60,249,1,0,1,249,1,249,5e-131, 455
So when you are referencing to your splitStringwith those indexes (1, 13) your result might probably be wrong.
Second
Try to specify what kind of type your array is, Dim splitString as Array should be Dim splitString As String()
Third
Make your code more readable/maintainable and easy to edit (not only for you, but others)
The Code
Private const FirstIndex = 1
Private const SecondIndex = 12
Sub Main
Dim myDelimiter As Char
Dim myString As String
Dim mySplit As String()
Dim myResult1 As String
Dim myResult2 As String
myDelimiter = ","
myString += "Query_1,ab563372363_C/R,100.00,249,0,0,1,249,1,249,1e-132, 460"
myString += "Query_1,ab563372356_C/R,99.60,249,1,0,1,249,1,249,5e-131, 455"
mySplit = myString.Split(myDelimiter)
myResult1 = mySplit(FirstIndex)
myResult2 = mySplit(SecondIndex)
Console.WriteLine(myResult1)
Console.WriteLine(myResult2)
End Sub
I am building a search engine in vb.net which would have to search for a word entered by the user in 40 text files within the project directory.
It should return the results as the total number of matches (text files) and the number of times this word is in each file. Any suggestions for a start would be grateful.
Regards.
get a list of the files in the directory with something like: Directory.GetFiles(ProjectDir, "*.*"), then read each file in the list like this:
Dim sr As StreamReader = New StreamReader(fileName)
Dim line As String
Do
line = sr.ReadLine()
scan the line and count
Loop Until line Is Nothing
sr.Close()
Try this code, in a console application, not only could find a word
even you can get the results using a RegEx Expression.
Class TextFileInfo
Public File As System.IO.FileInfo
public Count As Integer
public FileText As String
public ItMatch as Boolean = False
Sub New (FileFullName as String,WordPattern as String)
File = new System.IO.FileInfo(FileFullName)
Using Fs As System.IO.StreamReader(File.FullName)
FileText = Fs.ReadToEnd()'//===>Read Text
End Using
Count = _CountWords(WordPattern,FileText)
ItMatch = Count > 0
End Sub
Public Sub DisplayInfo()
System.Console.WriteLine("File Name:" + File.Name)
System.Console.WriteLine("Matched Times:" & Count)
End Sub
Private Function _CountWords(Word As String,Text As String) as Integer
Dim RegEx as System.Text.RegularExpressions.Regex(Word)
return RegEx.Matches(Text).Count'//===>Returns how many times this word match in the Text
End Fuction
End Class
Public Function SearchEngine(PatternWord As String,RootDirectory As String) List(Of TextFileInfo)
Dim MatchedFiles As New List(Of TextFileInfo)
Dim RootDir As New System.IO.DirectoryInfo(RootDirectory)
For Each iTextFile as System.IO.FileInfo In RootDir.GetFiles("*.txt")
'//===>Create a object of TextFileInfo and check if the file contains the word
Dim iMatchFile as New TextFileInfo(iTextFiles.FullName,PatternWord)
If iMatchFile.ItMatch Then
'//===>Add the object to the list if it has been matches
MatchedFiles.Add(iMatchFile)
End If
Loop
retur MatchedFiles '//===>Return the results of the files that has the matched word
End Function
Sub Main()
Dim SearchResults as List(Of TextFileInfo) = SearchEngine("JajajaWord","C:\TextFiles\")
For Each iSearch As TextFileInfo In SearchResults
iSearch.DisplayInfo()
Loop
End Sub