VB6 get text from richtextbox

Posted on 2004-09-01
Medium Priority
Last Modified: 2008-01-09
Can anyone give me a sample of VB6 code to get plaintext from a richtextbox in another application (which I do not have the source) into a buffer in my program. I then have to search this buffer for certain phrases.
I have used Sendmessage(hwnd, WM_GETTEXT, length, strtmp) which works for an hour or so but eventually crashes probably because the lenght is way over 64K and usually over 100k.
I see that I am supposed to use Sendmessage with EM_STREAMOUT. I haven't been able to get this to work and all the examples I can find are in C.
Thanks for any help.
Question by:aonecomputers
LVL 10

Expert Comment

ID: 11950867
can u select the contents of the RT box of other application...?

how do u manage to refer to that control when u dont have source of that application?

LVL 22

Accepted Solution

DarkoLord earned 500 total points
ID: 11952292
Hi! Try this (credits to "Frans C")... (replace RichTextBox1.hwnd with the correct hwnd)

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_USER = &H400
Private Const EM_STREAMIN = (WM_USER + 73)
Private Const EM_STREAMOUT = (WM_USER + 74)
Private Const SF_TEXT = &H1
Private Const SF_RTF = &H2
Private Const SF_UNICODE = &H10         ' Unicode data of some kind

    dwCookie As Long
    dwError As Long
    pfnCallback As Long
End Type

Private Sub Command1_Click()
Dim retval As Long
    es.dwCookie = 55 'put your own data in here, it is passed to the callback function
    es.pfnCallback = GetAddress(AddressOf EditStreamCallback)
    retval = SendMessage(RichTextBox1.hwnd, EM_STREAMOUT, SF_RTF, es)
End Sub

In a bas module:

Option Explicit
Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (Destination As Any, Source As Any, ByVal Length As Long)

Public Function EditStreamCallback(ByVal dwCookie As Long, ByVal pbBuff As Long, ByVal cb As Long, ByVal pcb As Long) As Long
Dim bArr() As Byte
Dim strBuff As String

    ReDim bArr(cb - 1)
    CopyMemory bArr(0), ByVal pbBuff, cb
    ' the data is in the byte array
    ' do with it what you want
    ' probably you want to save it to a file,
    ' but for the example I put it in a string
    strBuff = StrConv(bArr, vbUnicode)
End Function

Public Function GetAddress(ByVal lAddress As Long) As Long
    GetAddress = lAddress
End Function
LVL 17

Expert Comment

ID: 11956300
>>but eventually crashes probably because the lenght is way over 64K and usually over 100k.
It shouldn't crash.. a string can contain about 2 billion characters (about 1 billion if in Unicode).

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_GETTEXT = &HD
Private Sub Command1_Click()
    Dim strBuffer As String
    If WindowGetText(RichTextBox1.hwnd, strBuffer) = True Then
        'Just MsgBox the first 10 characters...
        Call MsgBox(Left$(strBuffer, 10) & "...", , "Length: " & Len(strBuffer))
    End If
End Sub
Private Sub Form_Load()
    'Fill RichTextBox with A LOT of text (may take a while)...
    RichTextBox1.Text = String(1000000, "0")
End Sub
Private Function WindowGetText(ByVal lngHandle As Long, ByRef strBuffer As String) As Boolean
    Dim lngLen As Long
    lngLen = SendMessage(lngHandle, WM_GETTEXTLENGTH, 0, 0)
    If lngLen > 0 Then
        strBuffer = String(lngLen, vbNullChar)
        If SendMessage(lngHandle, WM_GETTEXT, lngLen, ByVal strBuffer) = 0 Then
            WindowGetText = True
        End If
    End If
End Function

Featured Post

Free Tool: Port Scanner

Check which ports are open to the outside world. Helps make sure that your firewall rules are working as intended.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

Introduction While answering a recent question (http://www.experts-exchange.com/Q_27402310.html) in the VB classic zone, I wrote some VB code in the (Office) VBA environment, rather than fire up my older PC.  I didn't post completely correct code o…
Have you ever wanted to restrict the users input in a textbox to numbers, and while doing that make sure that they can't 'cheat' by pasting in non-numeric text? Of course you can do that with code you write yourself but it's tedious and error-prone …
As developers, we are not limited to the functions provided by the VBA language. In addition, we can call the functions that are part of the Windows operating system. These functions are part of the Windows API (Application Programming Interface). U…
This lesson covers basic error handling code in Microsoft Excel using VBA. This is the first lesson in a 3-part series that uses code to loop through an Excel spreadsheet in VBA and then fix errors, taking advantage of error handling code. This l…

587 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question