Deleting lines from RichText/RichEdit

[Grok]

This code is supposed to make sure I never go over 2000 lines in my RichTextBox.  It tries to delete any lines (from the top down) that exceed mMaxLines (2000). SOLVED.  I was using EM_SETSEL wrong.  The following code works.

Code Select Expand


Private Type TYPE_FINDTEXT
   cpMin As Long
   cpMax As Long
   lpstrText As String
End Type

Private Sub AddChat(ParamArray saElements() As Variant)
   Dim i As Integer
   For i = LBound(saElements) To UBound(saElements) Step 2
       With rtb
           .SelStart = Len(.Text) + 1
           .SelLength = 0
           .SelColor = saElements(i)
           .SelText = saElements(i + 1)            ' & Left$(vbCrLf, -2 * CLng((i + 1) = UBound(saElements)))
           .SelStart = Len(.Text) + 1
           .SelLength = 0
       End With
   Next i
   'keep only mMaxLines in the richtextbox
   Dim lRet As Long, LineCount As Long, TopLine As Long
   Dim strReplace As String, pCharPos As Long
   Dim lpFINDTEXTEX As TYPE_FINDTEXT
   strReplace = ""
   lpFINDTEXTEX.cpMin = 0                      'includes everything
   lpFINDTEXTEX.cpMax = -1                     'includes everything
   lpFINDTEXTEX.lpstrText = vbCrLf
   LineCount = SendMessage(rtb.hWnd, EM_GETLINECOUNT, ByVal 0&, ByVal 0&)
   Do While LineCount > mMaxLines
       pCharPos = SendMessage(rtb.hWnd, EM_FINDTEXTEX, ByVal 0&, lpFINDTEXTEX)
       If pCharPos > 0 Then
           pCharPos = pCharPos + 2
           lRet = SendMessage(rtb.hWnd, EM_SETSEL, ByVal 0&, ByVal CLng(pCharPos))
           lRet = SendMessage(rtb.hWnd, EM_REPLACESEL, ByVal 0&, ByVal strReplace)
       End If
       LineCount = SendMessage(rtb.hWnd, EM_GETLINECOUNT, ByVal 0&, ByVal 0&)
   Loop
   TopLine = SendMessage(rtb.hWnd, EM_GETFIRSTVISIBLELINE, ByVal 0&, ByVal 0&)
   frmGate.lblLineCount.Caption = LineCount
End Sub

[Eric]

This seems a little easier:

Code Select Expand


If SendMessageA(RTB.hWnd, EM_GETLINECOUNT, &H0, &H0) >= 2000 Then
       With RTB
           .SelStart = 0
           .SelLength = SendMessageA(RTB.hWnd, EM_LINELENGTH, &H0, &H0) + 2
           .SelText = ""
       End With
End If


[Grok]

Good computer science.  My art sucked.

[Skywing]

Note that this will cause major annoyance if you are trying to select some text while scrolled up a bit.

[Eli_1]

I never found out how to make it stop doing that when your scrolled up -- how would you?  

[Grok]

Note that this will cause major annoyance if you are trying to select some text while scrolled up a bit.

Then explain how to delete lines without using EM_SETSEL or equivalent?

[Eibro]

Note that this will cause major annoyance if you are trying to select some text while scrolled up a bit.

Then explain how to delete lines without using EM_SETSEL or equivalent?

Perhaps you could save the current selection and restore it afterwards.

[iago]

Note that this will cause major annoyance if you are trying to select some text while scrolled up a bit.

Then explain how to delete lines without using EM_SETSEL or equivalent?

Perhaps you could save the current selection and restore it afterwards.

But when you do that, don't forget that the location of the selection will change since you're removing text.