problem with wm_gettext

Visual Basic

    Sponsored Links


  • 1. Obtain Edit Control Identifier In Another Process
    I'm automating a Quickbooks function with VB6 and using SendMessage and PostMessage I can successfully show a form which changes a menu item and then enumerate those menu items and submenu items to obtain the correct menu item ID, and then PostMessage a WM_COMMAND using that menu item ID to show a dialog containing an edit control. I've tried sending TABs to move focus to the desired edit control on the dialog but that doesn't seem to work. If I manually click on the edit control I can send the keystrokes to it to produce the desired results but that defeats the purpose of this exercise. I think sending an EN_SETFOCUS to the edit control would work but I need the edit control identifier in addition to the window handle. I've searched and searched but either I'm lacking the correct magic words or this is the wrong approach. How can I set focus to an edit control in another process or how I can enumerate the control IDs on a dialog to obtain the edit control identifier? Frank
  • 2. Pinnacle-BPS Graph Control
    Hi I am using the Pinnacle-BPS Graph Control to graph the quantity of items in stock in a bar graph (Horizontal - gphBar2D). The values used for the graph are stored in an array, i(1-100). The data bars, by default, display in a default color set of rotating colors. All of this is working well. The change I wish to make is that I want to control the color of the data bar on a graph, based on its value instead of letting the control assign the color. I have read that you can assign colors based on its value but cannot find any documentation on how to do this. My current code for building the string by pulling the data from an array as follows: ' ' Build graph string ' x = "" For Counter = 1 to 100 x = x & Str(i(Counter)) + Chr$(9) Next GraphDataString = x ' ' Display the string to a graph ' Graph1.GridStyle = 2 Graph1.QuickData = GraphDataString Graph1.DrawMode = 2 ' This all works well excepting I would like to control the color of the data bar something like the following. ' x = "" For Counter = 1 to 100 if i(Counter < 15 then x = x & Str(i(Counter)) IN THE COLOR RED + Chr$(9) else x = x & Str(i(Counter)) IN THE COLOR BLUE + Chr$(9) end if Next GraphDataString = x ' ' Display the string to a graph ' Any help will be greatly appreciated. Thanks in Advance Sherry
  • 3. vb6.sp6/vista install issue
    I am trying to install vb6 sp6 on a vista business machine. I am getting an error that it cannot locate my vb6 though I can open vb6 with no problems. I have tried running as admin, ual on and off. Any help appreciated!

problem with wm_gettext

Postby Jim Bauer » Sun, 25 Apr 2004 03:57:00 GMT

I am trying to get the text of a window by sending that window a
WM_GETTEXT message.
The below code compiles correctly, but the "buffer" string variable
I've declared is blank.

Private Declare Function SendMessage 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_GETTEXT = &HD
Private Const wm_gettextlen = &HE

public function GetText(hwnd as long) as string
Dim buffer As String
SendMessage hwnd, WM_GETTEXT, wm_gettextlen, ByVal buffer
GetText = buffer
End Function

***END of code***
Any pointers as to what I'm doing wrong?
Cheers, Jim

Re: problem with wm_gettext

Postby Tom Esh » Sun, 25 Apr 2004 04:48:57 GMT

On Fri, 23 Apr 2004 18:57:00 GMT, Jim Bauer < XXXX@XXXXX.COM >

1) Your SendMessage declare is wrong for this case. lParam should be
ByVal As String, or simply As Any (specify ByVal in the call).

2) You must pre-allocate buffer to at least the number of chars
expected, iow at least what you tell it the size is in wParam. If
you've really no idea of the required size, you can use the
WM_GETTEXTLENGTH message. Note however this is a separate message and
requires a separate call. (Your wm_gettextlen const declare and usage
indicates you may be confused on this point.)

3) wParam should be the pre-allocated buffer size.

Declare Function SendMessage Lib "user32" Alias "SendMessageA" _
	(ByVal hWnd As Long, ByVal wMsg As Long, _
	ByVal wParam As Long, lParam As Any) As Long

Dim Buffer As String
Dim lSize As Long
Dim lRet As Long

lSize = SendMessage(hwnd, WM_GETTEXTLENGTH, 0&, ByVal 0&)
Buffer = String(lSize + 1, 0)
lRet = SendMessage(hwnd, WM_GETTEXT, lSize, ByVal Buffer)
If lRet > 0 Then
	Buffer = Left$(Buffer, lRet)
End If

MVP - Visual Basic
(please post replies to the newsgroup)

Similar Threads:


I have written two standard apps (not ActiveX) in VB6 SP6.  These apps 
communicate with one another via SendMessage API utilizing hidden text boxes 

The scenario is the "server" app has a few hidden textboxes (channels) which 
it uses to send various commands to the "client" app.  When the server 
starts the client app (Shell, not ActiveX) it passes the wHnd to those 
textboxes as command line args.  The client app then while running (this app 
runs a never ending loop) at regular frequent intervals issues a SendMessage 
WM_GETXT to the various channels (depending on where in the processing loop 
it is) to get instructions from the server.  The client also issues 
SendMessage WM_SETTEXT messages (to a different window on the server) to 
provide status and progress info back to the server.

The problem is that it appears as though the client app hangs after issuing 
the WM_GETTEXT message until some event occurs on the client.  The event 
that I know will wake the client back up is a mouse_move over its form. 
This is a problem since the client has no reason to have a UI (it is a 
background process).  Any way here is the scenario; App1 (the server) starts 
and shell starts App2 (the client). App2 then goes into a polling loop 
polling the hidden text boxes on App1 for instructions.  For debugging 
purposes I have added a form to App2 that simply displays one text box for 
each hidden text box in App1 and populates those text boxes with the text 
commands received via SendMessage WM_GETTEXT calls.  With both windows 
(App1s and App2s) visible I click a button on App1 which sends a command to 
one of the hidden communication textboxes.  In the App2 window I should see 
the text displayed in the corresponding textbox.  I do not though, and 
infact it appears (from other debug messages which should but are not being 
shown in another textbox on App2) as though App2 is hung, however if I then 
move the mouse over App2's window the app un-hangs receives the command and 

Anyone have any thoughts on why this is happening?

Thanx in advance for your help
Steve result with WM_GETTEXT

3.WM_GETTEXT hangs up

Hi all

I noticed that when I try to get text from one particular window calling 
SendMessage(hWnd, WM_GETTEXT...
the application hangs up until I close it using Task Manager.
For all other windows this call works fine.
The window's class = "Shell Embedding", invisible, RECT=0,0,0,0
Any ideas?
Definitely, I didn't have this problem yesterday, because I tested my 
application sending this message to all windows in the desktop tree (about 
1060 of them).
By the way I've got only one window of this class.

Thank you

4.WM_GETTEXT function


Hi all,

I'm trying to capture the text from a popup window (i.e. a MsgBox). The code


Dim lHandle As Long
Dim length  As Long
Dim result  As Long
Dim strtmp  As String

lHandle = FindWindow(vbNullString, "Some Popup")

 If lHandle <> 0 Then

    length = SendMessage(lHandle, WM_GETTEXTLENGTH, ByVal 0, ByVal 0) + 1

    strtmp = Space(length - 1)
    result = SendMessage(lHandle, WM_GETTEXT, ByVal length, ByVal strtmp)

 End If

gives me the title of the popup window ('Some Popup') but not the msg on the
popup. How kan I get the message?


7. Unknown pointer problem between Visual Basic and C (problem solved)

8. problems converting C# code to (MSMQ formatter problem)

Return to Visual Basic


Who is online

Users browsing this forum: No registered users and 97 guest