Use of DIALOG END

[Barney Winton]

Can any one tell me when the DIALOG END statement can be used without causing a GPF?

Example.(Created using CONTROL ADD...under PBMAIN) text box receives input that requires the program to close.Processing by callback attached to DIALOG SHOW statement results in a GPF.

Is it possible to fire the %WM_SYSCLOSE event and if so, does it do it cleanly ie: without causing a GPF.

I have used Callbacks attached to CONTROL ADD BUTTON statements that just do a DIALOG END and they work.
Problem is that the only other control is the System Close. I dont want to add a Close button if I can do without it.

[Lance Edmonds]

You can certainly use DIALOG END inside the dialog callback, but it should not be used in response to certain messages, such as %WM_INITDIALOG, etc. The most common position is (as you note) in response to %WM_COMMAND messages.

If you need to use END DIALOG in an "inappropriate" message handler, then the solution is to post the dialog a user-defined message and then use DIALOG END in response to the %WM_USER + 999& message.

ie, in psuedo code:

CALLBACK FUNCTION MyDialogCallback
  IF CBMSG = lMessage& THEN ' lMessage& is the message you want to end the dialog from
    PostMessage CBHNDL, %WM_USER + 999&, 0, 0)
  ELSEIF CBMSG = %WM_USER + 999& THEN
    DIALOG END CBHNDL
  END IF
END FUNCTION

If you are still having problems, then may I suggest that you post your problematic code in compilable form so that we can duplicate the problem you are having.


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

[Barney Winton]

Lance..

Your solution works great !. I guess I will have to be a bit more adventurous now I am getting a feel for the product.

'===============================================================
'
' SAMPLE PROG TO DEMONSTRATE ENDING PROG WITHOUT CAUSING GPF
'
'=================================================================
#COMPILE EXE
#REGISTER NONE
#INCLUDE "WIN32API.INC"


%TEST = 1
%PM_END = %WM_USER + 999

' App equates
'-------------------------------------------
$AppTitle = "PROGRAM ENDING"

' Control ID's for updateable controls
'-------------------------------------
%ID = 100
%ID_OPTION = 101

' Globals
'-------------------------------------
GLOBAL hDlg AS LONG

CALLBACK FUNCTION TestIt

ON ERROR RESUME NEXT

LOCAL lsA AS STRING

SELECT CASE CBMSG

CASE %WM_COMMAND

SELECT CASE CBCTL


' Options window
CASE %ID_OPTION

SELECT CASE CBCTLMSG

CASE %EN_CHANGE ' sent when user changes contents of edit box
' AFTER change is displayed - @ each keystroke.

CONTROL GET TEXT hDlg, %ID_OPTION TO lsA
SELECT CASE LEN(lsA)
CASE 1
IF lsA = "E" THEN

PostMessage CBHNDL, %PM_END, 0, 0

' causes a GPF
'------------------
' DIALOG END CBHNDL, 0

END IF

END SELECT ' LEN(lsA)

END SELECT ' CBCTLMSG

END SELECT ' CBCTL

CASE %PM_END

DIALOG END CBHNDL, 0

END SELECT ' CBMSG

END FUNCTION


regards

Barney
FUNCTION PBMAIN

ON ERROR RESUME NEXT


' Create our primary GUI
'-----------------------
DIALOG NEW 0, $AppTitle, 0, 0,400, 300, %WS_CAPTION OR %WS_SYSMENU OR %WS_SYSMENU OR %DS_CENTER, %WS_EX_APPWINDOW TO hDlg
CONTROL ADD TEXTBOX, hDlg, %ID_OPTION, "", 300, 260, 60, 14,%ES_UPPERCASE OR %WS_TABSTOP, %WS_EX_CLIENTEDGE

DIALOG SHOW MODAL hDlg, CALL TestIt

PBMAIN = 0

END FUNCTION


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[This message has been edited by Barney Winton (edited March 01, 2000).]