Using the New DLCall Function to call the Win API SendMessage Function we can
Select and DeSelect a ListBox's items in a few lines of code without iterating
through the entire list. Here's How:
First, put the following Declaration where it will be called ONLY ONCE during a
given RBase User Session, likely in a StartUp File of some kind. (Yes the
Pluses are line continuation so the news reader wouldn't wrap it)
-- Declaration of SendMessage:
StdCall function 'SendMessageA' +
alias 'SendMessage' +
(Integer, Integer, Integer, Integer) : Integer
Then on a form put a ListBox of some kind although I only tested it with a
variable User Defined ListBox.
assign it a Component ID (I used LBList )
in the OnAfterStart EEP , Set the ListBox to MultiSelect:
PROPERTY lblist multiselect 'true'
Put a couple of buttons on the form, One to Select All and one To DeSelect All
The Code for Select ALL:
--Begin
SET VAR vhnd TEXT = NULL
GETPROPERTY lblist handle vhnd
SET VAR vhwnd INTEGER = (INT(.vhnd))
SET VAR vret INTEGER = NULL
SET VAR lb_setsel INTEGER = 389
SET VAR vlparam INTEGER = -1
--SET VAR vbool INTEGER = 0 -- false removes Selected
SET VAR vbool INTEGER = 1 -- true Sets Selected
SET VAR vret = +
(dlcall('User32', 'SendMessageA' , vlparam, vbool, lb_setsel, vhwnd))
RETURN
--End
The Code for DeSelect ALL:
--Begin
SET VAR vhnd TEXT = NULL
GETPROPERTY lblist handle vhnd
SET VAR vhwnd INTEGER = (INT(.vhnd))
SET VAR vret INTEGER = NULL
SET VAR lb_setsel INTEGER = 389
SET VAR vlparam INTEGER = -1
SET VAR vbool INTEGER = 0 -- false Removes Selected
--set var vBool integer = 1 -- true Sets Selected
SET VAR vret = +
(dlcall('User32', 'SendMessageA' , vlparam, vbool, lb_setsel, vhwnd))
RETURN
--End
That's All there is to it. If you want to download a fully functioning demo,
here is the link (Just remember to execute the delcaration of the SendMessage
Function prior to running the form)
www.byerley.net/KT_ListBox.zip
Mike Byerley
"We Cannot Approach or Discuss 'YES', Until we
Have A Complete And Thorough Understanding Of 'NO'"
--- RBASE-L
================================================
TO POST A MESSAGE TO ALL MEMBERS:
Send a plain text email to [email protected]
(Don't use any of these words as your Subject:
INTRO, SUBSCRIBE, UNSUBSCRIBE, SEARCH,
REMOVE, SUSPEND, RESUME, DIGEST, RESEND, HELP)
================================================
TO SEE MESSAGE POSTING GUIDELINES:
Send a plain text email to [email protected]
In the message SUBJECT, put just one word: INTRO
================================================
TO UNSUBSCRIBE:
Send a plain text email to [email protected]
In the message SUBJECT, put just one word: UNSUBSCRIBE
================================================
TO SEARCH ARCHIVES:
Send a plain text email to [email protected]
In the message SUBJECT, put just one word: SEARCH-n
(where n is the number of days). In the message body,
place any
text to search for.
================================================
