UserControl Help...

[vbman213]

I am making a custom textbox control

and my problem is when I try to map the textboxes multiline property to a property in my usercontrol it errors and says it is readonly...

How can I get pass this?

[chemicalNova]

You can force its setting by throwing ES_MULTILINE into its window style. This is just pseudo-code as I don't have VB installed anymore.. but:

SetWindowLong(TextBox.hWnd, GWL_STYLE, ES_MULTILINE)

chem

[vbman213]

I need to know the const values of GWL STYLE And ES_MULTILINE

[chemicalNova]

They are in your API Text file that comes with VB. Go to the API viewer and load the APIs, then search the constant values.

Or, just type GWL_STYLE and ES_MULTILINE into google..

chem

[vbman213]

This method doesn't work...

[chemicalNova]

Show your code.

chem

[vbman213]

In a module I have the api and the two const...

and in the form_Load sub I have

SetWindowLong Text1.hwnd, GWL_STYLE, ES_MULTILINE

[chemicalNova]

Having looked into it further.. the MultiLine property is unchangable at runtime.. no matter how hard you try. Heres a workaround though:

Dim MaxLines As Long
 
Private Declare Function SendMessageLong Lib _
    "user32" Alias "SendMessageA" _
    (ByVal hwnd As Long, _
     ByVal wMsg As Long, _
     ByVal wParam As Long, _
     ByVal lParam As Long) As Long
 
Const EM_LINEFROMCHAR = &HC9&
 
Private Sub Text1_Change()
  Static LastText As String
  Static LastCaretPos As Long
  Static SecondTime As Boolean
  Dim CurrentCaretPos As Long
  Static NotFirstTime As Boolean
  If NotFirstTime = False Then
    NotFirstTime = True
    Exit Sub
  End If
  With Text1
    If Not SecondTime Then
      CurrentCaretPos = .SelStart
      .SelStart = Len(.Text)
      If SendMessageLong(.hwnd, EM_LINEFROMCHAR, _
                         -1&, 0&) + 1 > MaxLines Then
        Beep
        SecondTime = True
        .Text = LastText
        .SelStart = LastCaretPos
      Else
        LastText = .Text
        .SelStart = CurrentCaretPos
        LastCaretPos = .SelStart
      End If
    End If
  End With
  SecondTime = False
End Sub
 
Private Sub Form_Load()
  ' Here, I am setting MaxLines to 100 lines just to give
  ' the code something to work with initially. You can set
  ' this initial value to whatever you want and, of course,
  ' reset it to any other value (for example, 1 to make it
  ' a single line entry TextBox
  MaxLines = 100
End Sub

Set the MultiLine property to True at design time. If you want it to be 1 line only, set MaxLines to 1. For multiline.. set it to a larger number.

chem

[brucevde]

Another option is to use two TextBox controls in your user control. One for single line, one for multiline. Show/Hide the textboxes as appropriate.