Realtime richtext box updating while editing

[me_go_fast]

Hello, I am glad to have come across a seamingly helpful community as this one! I am a vb 6 devoloper and a few friends and i are currently stumped on an interesting problem. We need to create a rich text box that can be updated while a user is typing somewhere else in the document. Pretty much we need to update text that is not at the cursor. We have created our own user control, but still havent been able to figure out how to do that.

weve briefly looked into data grid controls but they do not have the formatting we are looking for and ultimatly just isnt as clean.

Any help is muchly appreciated. Thanks!

[isnoend07]

try this

Private Sub Text3_KeyPress(KeyAscii As Integer)
With rtb
.SelText = .SelText & Chr(KeyAscii)

End With
End Sub

[me_go_fast]

Thanks for the help. Unfortunately that will not work because we want to make it so that the text in the same rich text box can change dynamically while still having the user to be possibly typing at the time. For example, there is a timer that adds a "+" at the beginning of the rich text box every second, but we are having problems with when typing in the textbox and that timer fires with displaying correctly. We don't want the cursor to have to jump back to the beginning of the rich text box to add the "+" and interfere with the user entering text into the rich text box.

Again thanks for your thoughts, any help is muchly appreciated!

[akhileshbc]

In the timer event, write a line a of code after the code for "+".

Text1.selstart=len(Text1.text)

Not sure, but just try it. It will place the cursor at the end of the TextBox, so the user can continue typing.....

[Merri]

Humm, I guess this would be considered a flaw in the standard richtextbox control as it lacks a feature that can be found in the RichEdit control that it implements. There are alternative solutions that allow to use a Range to modify text anywhere in the textbox without it interrupting anything, not causing screen to scroll or blink etc. - too bad that would mean downloading some other OCX that may have other flaws.

Anyways, the way to go with SelText:

Private Sub Timer1_Timer()
    Dim lngSelStart As Long, lngSelLen As Long
    lngSelStart = RichTextBox1.SelStart + 1
    lngSelLen = RichTextBox1.SelLength
    RichTextBox1.SelStart = 0
    RichTextBox1.SelText = "+"
    RichTextBox1.SelStart = lngSelStart
    RichTextBox1.SelLength = lngSelLen
End Sub

[me_go_fast]

hmmm... ok, thank you everybody for your suggestions. The method described would work with it jumping back to the end, but we are somewhat afraid after the number of lines increases the process is going to become slower and slower to the point of a nuissance to the end user. Does anyone have any ideas what other ocx's are out there that might work? I thought about creating my own, but I haven't been able to find much on how to create my own richtext box giving me the ability to add such a feature.

Again, thanks for the suggestions!

[iPrank]

This seems working.
Needed to add a LockWindowUpdate and EM_GETSCROLLPOS/EM_GETSCROLLPOS to get/set current scrolling position of RTB. It flickers a little (due to the call to LockWindowUpdate).

Option Explicit
Private Const WM_USER As Long = &H400
Private Const EM_GETSCROLLPOS As Long = (WM_USER + 221)
Private Const EM_SETSCROLLPOS As Long = (WM_USER + 222)
'
Private Type POINT
    X As Long
    Y As Long
End Type
'
Private Declare Function SendMessage _
                Lib "user32.dll" _
                Alias "SendMessageA" (ByVal hwnd As Long, _
                                      ByVal wMsg As Long, _
                                      ByVal wParam As Long, _
                                      ByRef lParam As Any) As Long
Private Declare Function LockWindowUpdate _
                Lib "user32" (ByVal hwndLock As Long) As Long
 
Private Sub Timer1_Timer()
    Dim lngSelStart As Long, lngSelLen As Long
    Dim CurrentPos As POINT
    '
    LockWindowUpdate RichTextBox1.hwnd
    SendMessage RichTextBox1.hwnd, EM_GETSCROLLPOS, 0, CurrentPos ' Get current scrolling position
    '
    lngSelStart = RichTextBox1.SelStart + 1
    lngSelLen = RichTextBox1.SelLength
    RichTextBox1.SelStart = 0
    RichTextBox1.SelText = "+"
    RichTextBox1.SelStart = lngSelStart
    RichTextBox1.SelLength = lngSelLen
    '
    SendMessage RichTextBox1.hwnd, EM_SETSCROLLPOS, 0, CurrentPos
    LockWindowUpdate 0
End Sub

[Merri]

It would be cleaner to make a call to WM_SETREDRAW to disable the painting temporarily. I'll see if I make a sample later, now I have to eat.

[Merri]

Here:

Option Explicit

Private Declare Function InvalidateRect Lib "user32" (ByVal hWnd As Long, ByVal lpRect As Long, ByVal bErase As Long) As Long
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_SETREDRAW = &HB&

Private Sub Timer1_Timer()
    Dim lngSelStart As Long, lngSelLen As Long, lngScrollPos(1) As Long
    SendMessage RichTextBox1.hWnd, WM_SETREDRAW, 0, ByVal 0&
    lngSelStart = RichTextBox1.SelStart + 1
    lngSelLen = RichTextBox1.SelLength
    RichTextBox1.SelStart = 0
    RichTextBox1.SelText = "+"
    RichTextBox1.SelStart = lngSelStart
    RichTextBox1.SelLength = lngSelLen
    SendMessage RichTextBox1.hWnd, WM_SETREDRAW, -1&, ByVal 0&
    InvalidateRect RichTextBox1.hWnd, 0, 0
End Sub

No blinking. But the scroll issue remains. EM_GETSCROLLPOS and EM_SETSCROLLPOS are not enough. One should also find out whether the view is at the bottom or not before using them, because otherwise it just gets stuck in the beginning.