How to stop a code when checking is completed?

Firstly, my apologies to the other members for posting this a solution - it's too long for a comment.

You have posted several questions regarding this project. Lately...

Member 11788899 wrote:

Chill60, please help with some code?

The short answer is that I'm not prepared to spend large amounts of my time writing code for you. I doubt you will find anyone else here who will.

However, I will give you some sound advice on the approaches you should take.

1. Throw away the code you already have for CheckForReplacementText

2. Decide on what you are actually trying to do - either drive the check from the contents of the RTB word by word OR drive the check from the list of replacements that you have.

3. Do NOT write a recursive procedure. This means that if somewhere in your CheckForReplacementText routine you write CheckForReplacementText() you are writing a recursive routine. I say again, don't.

4. ContextMenuStrip is the wrong way to present the suggested replacements to the user - you will get (have already got) yourself in a right mess trying to handle the response from it.

5. Do use a pop-up form by using ShowDialog - e.g. have a borderless form with only a ListBox that you populate, a property that exposes which item was selected and a public method to populate the list. E.g.

Public Class Suggestions
    Public Property Action As String
    'Form has FormBorderStyle = None
    Public Sub PopulateMe(suggests As List(Of String))
        'avoid the Items collection cannot be modified when the DataSource property is set.
        Dim fullList As List(Of String) = suggests.ToList()
        If suggests.Count = 0 Then
            fullList.Add("No Suggestions")
        End If
        fullList.Add("--------------")
        fullList.Add("Cancel checking")

        lstSuggestions.Items.Clear()
        lstSuggestions.DataSource = fullList
    End Sub
    Private Sub lstSuggestions_DoubleClick(sender As Object, e As EventArgs) Handles lstSuggestions.DoubleClick
        HandleSelection()
    End Sub
    Private Sub lstSuggestions_KeyDown(sender As Object, e As KeyEventArgs) Handles lstSuggestions.KeyDown
        If e.KeyValue = Keys.Enter Or e.KeyValue = Keys.Return Then
            HandleSelection()
        End If
        If e.KeyValue = Keys.Escape Then Close()
    End Sub
    Private Sub HandleSelection()
        If lstSuggestions.SelectedValue.ToString().Substring(1, 1) = "-" Then
            Exit Sub
        End If
        Action = lstSuggestions.SelectedValue
        Close()
    End Sub
End Class

Which you can call from within your loop like this

Dim f As Suggestions = New Suggestions()
f.PopulateMe(checkList)
Dim result = f.ShowDialog(RichTextBox1)
If result = DialogResult.Cancel Or f.Action = "Cancel checking" Then
    Exit Sub
End If

6. Start with a small amount of text and a small number of replacements - it will be easier to Debug

7. Which leads me to the point - learn how to debug - see this CP article for more information on this skill Mastering Debugging in Visual Studio 2010 - A Beginner's Guide[^]

8. Finally, really give some thought to how you are suggesting your replacements ... consider the text "How to fool someone" - you might want to suggest "confuse" for fool here used as a verb. But then what about "She cooked a raspberry fool" - here "fool" is a noun and you might want to suggest "dessert". But "fool" is also a noun in the sentence "He is a fool" - where you might want to suggest "idiot".
One way around this is to store these in a Dictionary(Of String, List(Of String)) rather than just a

Dictionary(Of String, String)<br />

e.g.

Dim replacements As Dictionary(Of String, List(Of String)) = New Dictionary(Of String, List(Of String))()
replacements.Add("fool", New List(Of String)({"confuse", "idiot", "dessert"}))
replacements.Add("unknownword", New List(Of String)({"no suggestions"}))

Over to you. If you have a genuine problem with code that you have written then please come back with more questions. We will be more than happy to help - if you help yourself first.