LEFT$ problem

[George Deluca]

In trying to track down an intermittent bug, I've narrowed it down to the following tiny point.

The code is from a small preferences dialog. The failing part has to do with a simple TEXT box which the user can leave blank or enter a single character into.

Retrieving was not always successful as sometimes, when a character was entered, it did not appear to be detected. So I added some MSGBOX's and ran through it over and over.

1. ERR is always zero, as expected.
2. The 1st display of LeftClickChar is ALWAYS correct (what was entered).
3. The 2nd display of LeftClickChar is blank about 1/2 the time, not always.
4. LeftClickChar is just a simple dynamic STRING.

I can't believe LEFT$ is failing, but it sure looks like that.
EDIT: I switched to MID$(xxx, 1, 1) from LEFT$ but no difference, but what else can alter the string between the MSGBOX's?

Any other thoughts? I'm tearing my hair out.

George

   CONTROL GET TEXT hMouse, %MOUSE_LEFTCLICK_CHAR TO LeftClickChar
   MSGBOX "Err=" & FORMAT$(ERR)
   MSGBOX LeftClickChar
   LeftClickChar = LEFT$(LeftClickChar, 1)
   MSGBOX LeftClickChar

[Chuck de Young]

There might be a none displaying character in the string. Why not print the Length of the string, which you think will be one, but ???. Also print the Format$(Asc(LeftClickChar)) to see what you really have.

Chuck

[George Deluca]

Left$ problem - please ignore

Smacking forehead with a large hammer here.

Guess what a leading blank does.

Can't believe I've wasted so much time on this.

Grrrr..


Many, many thanks,

George

[Mel Bishop]

Don't think for a minute you are the only one that's been-there-done-that, George.

[Bern Ertl]

BTW, you can use:

CONTROL POST hDlg, %IDC_TEXTBOX1, %EM_LIMITTEXT, 1, 0

to force the textbox to only accept 1 character (thus avoiding the need to use LEFT$). Adjust the %id as necessary of course.

[Lee Bergeron]

You can also use the TRIM$ Command -

LeftClickChar = LEFT$(TRIM$(LeftClickChar), 1)

[George Deluca]

Bern: Thanks a lot. I'd been looking for a way to limit the input in the PB help, but found nothing. I didn't even know messages like this existed.

As you can guess, this is my 1st go-round at dialogs. Makes me appreciate the enormous grunt-work that must go into the interfaces for some apps, let alone that needed to actually DO the real work.

I thought retirement was going to be easy; I thought I'd escaped the perpetual learning curve.


George