Advanced Replacement Freeze - vb.net

Question

Basically I'm creating a tool which while is looking through lines of "file.txt" to replace a word from a textbox's content with that line if the line is containing that word.
Basically if the line is: pizza-cheese-potatoes, all the words containing "pizza" or "cheese" or "potatoes" to be replaced with "pizza-cheese-potatoes"
Here is what I have until now. But it freeze and I don't really know why. Please help me. :)
Dim PATH As String = "C:\test.txt"
Sub Repl(x As String)
For Each line As String In File.ReadLines(PATH)
Dim myList = New List(Of String)(line.Split("|"c))
For Each item As String In myList
If x Is item Then
TextBox1.Text.Replace(x, line)
End If
Next
Next
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
For Each word As String In TextBox1.Text.Split(" "c)
Repl(word)
Next
End Sub
Thank you in advance!

Answer 1

Try doing it like this instead.
Public Sub DoWork()
Dim lines = IO.File.ReadAllLines(PATH)
For Each line In lines
Dim myList = New List(Of String)(line.Split("-"c))
For Each item In myList
If TextBox1.Text.Contains(item) Then
TextBox1.Text = TextBox1.Text.Replace(item, line)
End If
Next
Next
End Sub
Your reader reads the file multiple times which is massively inefficient. This code reads it once, then we just loop over each line with no need to worry about exit conditions etc.
However it's not really doing anything useful as you're not pausing after each line so you'll only be able to review the final one.
There is also no need to test if the textbox contains the text, just simply do a replace then you only search the text once.
For Each item In myList
TextBox1.Text = TextBox1.Text.Replace(item, line)
Next
-------- edit --------
To fix the issue with replacing the word you've already replaced you could try using a replacement placeholder.
For Each item In myList
TextBox1.Text = TextBox1.Text.Replace(item, "#")
Next
TextBox1.Text = TextBox1.Text.Replace("#", line)
---------- edit 2 ------------------
You want to try and build up a new string, word by word, instead of replacing the text in the textbox. This is so that words you've substituted already don't get converted.
Function ReplaceWord(word As String, lines As String())
For Each line As String In File.ReadLines(PATH)
Dim myList = New List(Of String)(line.Split("|"c))
For Each item As String In myList
If word = item Then
Return line
End If
Next
Next
Return word
End Function
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim result As New System.Text.StringBuilder
Dim lines = File.ReadLines(PATH)
For Each word As String In TextBox1.Text
result.Append(ReplaceWord(word, lines)).Append(" ")
Next
Textbox1.Text = result.ToString()
End Sub