editchanging event

[Arnoud Oortwijk]

Does anybody know if the dwneditchanging event on a DW control has a return
value that ommits the last key stroke?

My problem is as follows.
I have a decimal column on a DW. I to prevent the user from entering invalid
characters like abc etc.
I know I can do this using the editchange event. But when the the user
enters 1.a I want to ommit the 'a' only 1. should remain in the edit field.

I want to implement this on my ancestor object. As such I'd prefer not to
use edit masks.

Any help would be greatly appreciated.

Kindest regards,

Arnoud

[Philip Salgannik]

Editchanging won't help you.
You need pbm_dwnkey combined with Peekmessage API:
function boolean PeekMessageA (ref blob lpMsg, long hWnd, uint
uMsgFilterMin, uint uMsgFilterMax, uint wRemoveMsg) library "user32.dll"

In pbm_dwnkey you'll write smth like:

blob{28} lblb_msg
integer lpdot
string lscurrt
boolean lb_remove

CHOOSE CASE key
CASE Key1!, Key2!, Key3!, Key4!, Key5!, Key6!, Key7!, Key8!, Key9!,
Key0!, KeyBack!, &
KeyDelete!, keyleftarrow!, keyrightarrow!, keynumpad0!,
keynumpad1!, keynumpad2!, keynumpad3!, &

keynumpad4!,keynumpad5!,keynumpad6!,keynumpad7!,keynumpad8!,keynumpad9!

CASE keyperiod!

lscurrt = GetText()
lpdot = Pos(lscurrt, ".")
IF lpdot > 1 THEN
lpdot = Pos(lscurrt, ".", lpdot)
lb_remove = lpdot > 0
END IF

CASE ELSE
lb_remove = TRUE

END CHOOSE

IF lb_remove THEN PeekMessageA(lblb_msg,0,256,264,1)

RETURN 0

Obviously above has a very crude method of parcing for a decimal separator,
you'll have to come up with something production ready.

pbm_thisusuallydoesnothelp:-))
Philip Salgannik

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