VB - Limit TextBox Line Length

Someone asked once if it would be possible to limit the length of each line in a text box to 10 characters. This is the code I came up with:

VB Code:

Option Explicit
 
'API Declarations:
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" _
  (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, _
  lParam As Any) As Long
 
'Constant Delcarations
Private Const EM_LINEINDEX = &HBB
Private Const EM_LINELENGTH = &HC1
 
Private Sub Text1_KeyPress(KeyAscii As Integer)
Dim lLen As Long
 
  'Get the length of the current line:
  lLen = SendMessage(Text1.hwnd, EM_LINELENGTH, EM_LINEINDEX, 0&)
  
  'If length is 10, don't allow more characters:
  If lLen = 10 And KeyAscii <> vbKeyReturn And KeyAscii <> vbKeyBack Then
      KeyAscii = 0
  End If
  
End Sub

or you can just do this:

VB Code:

Text1.MaxLen = 10

a bit simpler

Quote:

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Originally posted by seec77
or you can just do this:

VB Code:

Text1.MaxLen = 10

a bit simpler

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Well, first, its MaxLength ;).

Second, that will limit the size of the whole textbox. Hobo's way, I believe, works on a line by line basis.

Quote:

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Originally posted by crptcblade
Second, that will limit the size of the whole textbox. Hobo's way, I believe, works on a line by line basis.

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Yes, indeedy.

I don't know why you'd want such a thing, but I figured since one person asked, others may as well. :)

whoops...
sorry, thought it was just for the whole textbox... anyway, sorry again...

Great Code!

One issue:

I modified the code so that when the line reaches a certain length (10 for this example), text1.text = text1.text & VBCRLF so that the new text starts on the next line. If i then go back up to the previous line, I can type the 11th character and keep typing past the original 10 characters. Is there any way to prevent this?

Quote:

---

Originally posted by The Hobo
Someone asked once if it would be possible to limit the length of each line in a text box to 10 characters. This is the code I came up with:

VB Code:

Option Explicit
 
'API Declarations:
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" _
  (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, _
  lParam As Any) As Long
 
'Constant Delcarations
Private Const EM_LINEINDEX = &HBB
Private Const EM_LINELENGTH = &HC1
 
Private Sub Text1_KeyPress(KeyAscii As Integer)
Dim lLen As Long
 
  'Get the length of the current line:
  lLen = SendMessage(Text1.hwnd, EM_LINELENGTH, EM_LINEINDEX, 0&)
  
  'If length is 10, don't allow more characters:
  If lLen = 10 And KeyAscii <> vbKeyReturn And KeyAscii <> vbKeyBack Then
      KeyAscii = 0
  End If
  
End Sub

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:) :eek: