Splitting a string of a multiline textbox by lines - excel

Question

I want to split the text of a textbox after a specific amount of visible lines.
I've found some codes that "allows that", but all of them consider the lines by the "vbCrLf" parameter, but i want to split using the visible lines of a multiline textbox.
To make it more clear to understand, consider a multiline textbox with the following text:
"The history of textbooks dates back to civilizations of ancient history. For example, Ancient Greeks wrote texts intended for education. The modern textbook has its roots in the standardization made possible by the printing press. Johannes Gutenberg himself may have printed editions of Ars Minor, a schoolbook on Latin grammar by Aelius Donatus. Early textbooks were used by tutors and teachers, who used the books as instructional aids (e.g., alphabet books), as well as individuals who taught themselves."
When i use the Textbox.Linecount function it returns the number 6 because the textbox shows six lines (which depends on the size of the control), but if i use a function like strText = Split(TextBox.Text, vbCrLf) it will return 1, because there is only one vbCrLf. But i need to split the text into two textbox considering the visible lines of the control, something like what happens in page breaks of MS Word.
For a better visual explanation, please look at the attached image.
Example

Answer 1

Firstly, I'm not convinced there is a robust and elegant way to do this, but it was fun to experiment and it might be useful to you.
The following will split the contents of TextBoxInput into TextBoxPage1 and TextBoxPage2 breaking on the line number specified by PAGED_TEXT_BOX_LINES.
It uses the textbox itself to detect natural line breaks and thus implicitly caters for the size of the textbox, the font, etc.
The desired line count is hard coded as a constant - not doing this would require an alternative of calculating the line height of the textbox (requiring calculations based on the font metrics and the textbox's internal line-leading size).
It only handles two "pages". But the concept could be extended simply by repeating the process based on the remainder of text that ends up in TextBoxPage2.
Private Sub CommandButton1_Click()
Const PAGED_TEXT_BOX_LINES As Integer = 5
Dim text As String
Dim i As Long
Dim textLength As Long
Dim curLine As Integer
text = TextBoxInput.text
textLength = Len(text)
TextBoxPage1.SetFocus
'add characters of the input string until the first page textbox
' exceeds maximum line count
For i = 1 To textLength
TextBoxPage1.text = Mid$(text, 1, i)
If TextBoxPage1.LineCount > PAGED_TEXT_BOX_LINES Then
'retreat cursor until we reach previous line, so we can
' detect the word that wrapped
curLine = TextBoxPage1.curLine
Do While TextBoxPage1.curLine = curLine
TextBoxPage1.SelStart = TextBoxPage1.SelStart - 1
Loop
'the remaining text after the SelStart is what
' wrapped, so stop page 1 after SelStart
TextBoxPage1.text = Mid$(text, 1, TextBoxPage1.SelStart)
TextBoxPage2.text = Trim$(Mid$(text, TextBoxPage1.SelStart + 1))
Exit For
End If
Next i
End Sub