Textbox holding more than 65535 characters using API

Could someone give me a direction on this?

This code from another source (with a minor change by me to print a bunch of "x"'s instead of blank spaces), suggests that you can use the API to get a textbox to hold more than 65535 characters. When I try it, the textbox is just plain white...no characters. At least none that I can see. I have gone to my API reference and everything looks just like it should be. So I am thinking the problem is because I haven't included code to tell what color to use for the text. Is this the case?

Many thanks!

Code:

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Option Explicit
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
Private Const WM_SETTEXT = &HC
Private Const EM_SETSEL = &HB1
Private loopo As Long

Private Sub Command1_Click()
  'Getting textbox to hold more than 65535 characters

  'Code by strongm at tek-tips.com, 6/2/2008:

  'Controls:
  'Command button named "Command1".
  'Textbox named "Text1", w vertical scrollbar.
 
  Dim result As Long
  Dim maxstring As String
   
  ' Simple demo that we can go over 65535 by just one extra character
  'maxstring = Space(65535) + "x"
   
  For loopo = 1 To 65536
    maxstring = maxstring + "x"
  Next loopo
   
  SendMessage Text1.hwnd, WM_SETTEXT, 0&, ByVal maxstring
  Debug.Print Len(Text1.Text) ' Note that once we've actually got the text into the textbox we can get it out (or information about it) OK
  SendMessage Text1.hwnd, EM_SETSEL, Len(Text1.Text), Len(Text1.Text)

Exit Sub
  ' Ok, let's be silly, and go with, say, 64Mb + 1...
  maxstring = Space(1024& * 1024 * 64) + "x"
  SendMessage Text1.hwnd, WM_SETTEXT, 0&, ByVal maxstring
  Debug.Print Len(Text1.Text)
  ' Position selection at end to demonstrate that Textbox can happily hold and
  ' display rather more text than we might expect ...
  ' Cannot use Textbox's own SetSel because that is limited by MS to a max of 65535
  ' (mind you, you'll notice a performance problem
  SendMessage Text1.hwnd, EM_SETSEL, Len(Text1.Text), Len(Text1.Text)
End Sub

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If I'm not mistaken the richtextbox does not have this limitation. I would try that if I needed to have that much data in a text box.

Try this:

Code:

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Option Explicit

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
Private Const WM_SETTEXT = &HC

Private Sub Command1_Click()
  Dim i                As Long
  Dim strText          As String

  Screen.MousePointer = vbHourglass
  For i = 0 To 10000
      strText = strText & CStr(i) & " Now is the time for all good men" & vbCrLf
  Next

  SendMessage Text1.hwnd, WM_SETTEXT, 0&, ByVal strText
 
  Screen.MousePointer = vbDefault
 
  MsgBox Len(Text1.Text), vbInformation, "Len(Text1.Text)"

End Sub

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Quote:

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If I'm not mistaken the richtextbox does not have this limitation. I would try that if I needed to have that much data in a text box.

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Funny you should mention that! :). I was having problems with an RTB and I was wondering if it had a limit. But it was another problem. But in the meantime, I was researching textbox limits and ran into this bit of code. So I thought I would just play with it and maybe add it to my "vb toolkit" for future use. But it doesn't print like it should.

DrUnicode> I tried your code but same problem. Could this be a vb6 under Win7 problem?

Works here with Win7 32-bit. Did you set TextBox to MultiLine before testing?

DoH! Grade school error there. I'm getting old. :)

It DOES work.

I may have to use this code as it turns out, because I have >65535 characters of text in an RTB I need to convert to plain text, and the easiest way seems to be copying the RTB into a Plain-Textbox, then parsing my strings from there.