Scrolling a RichTextBox

[Jdo300]

Ok, here's my problem. I have a RighTextBox, and I want my program to be able to automatically scroll the Horozontal scrollbar all the way back to the left. I tryed using the SendMessage API with the EM_SCROLL message, but I can't seem to get it to work. Any ideas?

[Muddy]

a quick "cheat" would be something like:

richtextbox1.selstart = 0

if that helps ...

[techyspecy]

Originally posted by Jdo300
Ok, here's my problem. I have a RighTextBox, and I want my program to be able to automatically scroll the Horozontal scrollbar all the way back to the left. I tryed using the SendMessage API with the EM_SCROLL message, but I can't seem to get it to work. Any ideas?

EM_Scroll would not help.

use these constants ..

Private Const SB_LINEDOWN As Long = 1
Private Const SB_LINEUP As Long = 0
Private Const SB_PAGEDOWN As Long = 3
Private Const SB_PAGEUP As Long = 2
Private Const WM_HSCROLL = &H114
Private Const WM_VSCROLL = &H115
 
'examples :
 
 intRet = SendMessage(richtextbox1.hwnd, _
                    WM_HSCROLL, _
                    SB_LINEUP, 0)
'and
 
 intRet = SendMessage(richtextbox1.hwnd, _
                    WM_VSCROLL, _
                    SB_PAGEUP, 0)

'And your rtb will scroll like hell ..

[Jdo300]

Ohhh ok. sure that sounds good, but a couple of problems there:

1. I need to scroll ONLY the horozontal scrollbar all the way to the left

2. the textbox would have a highlighted block of text in it, so I couldn't change anything with the SelStart,len,text properties.

3. I also looked up the EM_GETSCROLLPOS & EM_SETSCROLLPOS properties since the textbox i'm using is a RichTextBox, but I wrote a function like:

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_USER As Long = &H400
Private Const EM_GETSCROLLPOS As Long = (WM_USER + 221)
Private Const EM_SETSCROLLPOS As Long = (WM_USER + 222)

Private Type POINTAPI
    x As Long
    Y As Long
End Type

'Moves the Horozontal scrollbar in txtWindow all the way to the left
Public Function MoveScrollBar(RTB As RichTextBox)
    Dim PointX As POINTAPI 'X,Y struct containing the scroll position of the RichTextBox
    'Fill the PointX structure so the current Y position can be retrieved
    SendMessage RTB.hwnd, EM_GETSCROLLPOS, 0, PointX
    'Set the X to zero
    PointX.x = 0
    'Update the scrollbar position
    SendMessage RTB.hwnd, EM_SETSCROLLPOS, 0, PointX
    RTB.Refresh
End Function

and of course, it didn't work! I need help

[BuggyProgrammer]

it won't work because a richtextbox is not a textbox... amd EM_ messages are only for TEXTboxes.

[crptcblade]

Originally posted by BuggyProgrammer
it won't work because a richtextbox is not a textbox... amd EM_ messages are only for TEXTboxes.

That's not true at all. Most EM_xxxx messages will work for both rich and regular edit boxes.

[crptcblade]

Try this...

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
 
Private Const WM_HSCROLL = &H114
Private Const SB_LEFT = 6
 
Private Const SCROLL_AMT = 100& 'Increase as necessary
 
Public Function MakeDWord(LoWord As Long, HiWord As Long) As Long
    MakeDWord = (HiWord * &H10000) Or (LoWord And &HFFFF&)
End Function
 
'usage
Call SendMessageLong(RichTextBox1.hwnd, WM_HSCROLL, MakeDWord(SB_LEFT, SCROLL_AMT), 0&)

[Jdo300]

Thanks! It works great! But I have yet another problem! The reason I needed the horizontal scrollbar to automatically go left is because I've made some code that can block tab text, and I didn't want the box to scroll right when the text is tabbed. Now, the code you gave me works fine, but the whole box blinks whenever the scrollbar is adjusted. Is there a way to simply keep the textbox from scrolling right when the text is tabbed?