ComboBox odd behavior

[Mike Trader]

I have a dialog that creates a Combobox as part of its controls.

I want to process the result of the user choosing a diffrent item. When I use the ID in CBCTL the processing is done MULTIPLE times???

Also the this ID in CBCTL is called after I open a dialog box and the user selects a file. Why?

Here is the bare bones in an example:
(the show btn shows the number of times the ID is called.

#COMPILE EXE "Combo.exe" ' Combo problem example
#INCLUDE "WIN32API.INC" ' Win API definitions

GLOBAL Called AS LONG
'¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤'
CALLBACK FUNCTION MainCB() AS LONG

SELECT CASE CBMSG
CASE %WM_INITDIALOG
COMBOBOX ADD CBHNDL, 99, " CME 08:30 to 15:15"
COMBOBOX ADD CBHNDL, 99, " CBOT 08:30 to 15:15"
COMBOBOX ADD CBHNDL, 99, " NASDAQ 09:30 to 16:00"
COMBOBOX ADD CBHNDL, 99, " NYSE 09:30 to 16:00"
COMBOBOX ADD CBHNDL, 99, " AMEX 09:30 to 16:00"
COMBOBOX SELECT CBHNDL, 99, 1
END SELECT

SELECT CASE CBCTL
CASE 99
INCR called
'I want to CALL a function to process the ComboBox choice ONCE here
CASE 103
CONTROL SET TEXT CBHNDL, 114, " "+STR$(Called)
Called = 0
CASE 104 ' Quit
DIALOG END CBHNDL
END SELECT
END FUNCTION

'¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤'
FUNCTION PBMAIN
LOCAL hDlg AS LONG
DIALOG NEW 0, " example", 230, 60, 110, 159, 0 TO hDlg
CONTROL ADD COMBOBOX,hDlg, 99, , 4, 1, 102, 150, %CBS_DROPDOWNLIST
CONTROL ADD FRAME, hDlg, 100, "", 4, 13, 102, 93
CONTROL ADD FRAME, hDlg, 105, "", 4, 116, 102, 24
CONTROL ADD BUTTON, hDlg, 103, "Show", 35, 123, 40, 14, 0
CONTROL ADD BUTTON, hDlg, 104, "Quit", 5, 145, 100, 12, 1
CONTROL ADD LABEL, hDlg, 114, " ", 2, 108, 109, 12, 0
DIALOG SHOW MODAL hDlg CALL MainCB
END FUNCTION



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Kind Regards
Mike

[Bern Ertl]

Mike,

I think your SELECT CASE CBCTL structure should be
encapsulated inside a %WM_COMMAND case for the CBMSG structure.



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Bernard Ertl

[Lance Edmonds]

Not just that, but Mike should check the type of notification message for the control you are responding to... ie, test the value of CBCTLMSG. For example, you will likely be getting "UPDATE" and "CHANGE" messages, and responding to each one without regard to the context of the event.

------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

[Mike Trader]

so what am I looking for? What does the combobox send when the user makes a selection?
I only want it to call my function once, and I cont want it to call my function at any other time which it seems to be doing now.


Is this what i need:

SELECT CASE %WM_COMMAND
SELECT CASE CBCTL
CASE 99
IF LOWRD(CBCTLMSG) = %CBN_SELENDOK THEN
INCR called
'CALL a function to process the ComboBox choice ONCE here
end if

it seems to work but is it right?


------------------
Kind Regards
Mike

[Lance Edmonds]

Out of interest, can you tell us the purpose of the "SHOW" button?

If that is the "action" key (for the user to actually do something after making a selection in the combo), you would get the selection(s) from the combobox and process them when the SHOW button is clicked. However, your questions suggest you are doing something when a selection is made in addition to when the SHOW button is clicked.

Basically, when a selection is make (and especially if the combo has an edit control), you'll receive a series of messages from the combobox control. These notification messages are documented in MSDN and most good API programming books.

Therefore I have to ask... have you read the section on ComboBoxes in WIN32.HLP? It also outlines the notification messages a combobox generates and sends to the parent window/dialog callback function (WNDPROC) depending on the kind of user interraction event that occurred.


------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>