Question

Control Validation & the Tab Control

Asked by: mshire

Hi, I'm using VB.net and doing various validation on controls using the Validating event and setting the e.Cancel = true if the validation was unsuccessful.

This works fine on everything apart from when the user hits a tab on a tab control... its seems to fire the validating event 2/3 times but the tab still changes and an incorrect value is left stored in the control. Why should this happen, surely the tab control shouldn't receive the focus if I set e.cancel = true in the validating event...?

Any ideas?

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Asked On
2003-09-18 at 02:49:48ID20742199
Tags

tab

,

control

,

validating

Topic

.NET

Participating Experts
2
Points
125
Comments
8

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Answers

 

by: TheLearnedOnePosted on 2003-09-18 at 05:10:52ID: 9385536

This description is a little vague.


<< tab control shouldn't receive the focus if I set e.cancel = true in the validating event>>
The Validating event is when a control is about to lose focus.

The events occurs in this order:

Leave
Validating
Validated
LostFocus

So unless you are putting in e.Cancel=True in another control's Validating event, then the tab control will receive the focus.

 

by: morphinexPosted on 2003-09-18 at 06:40:35ID: 9386140

Try sticking in

e.handled = true

somewhere in the code.

 

by: mshirePosted on 2003-09-18 at 08:33:11ID: 9387040

Sorry...

I have a Textbox in which I'm doing some validation using the validating event. If the validation fails I set e.Cancel=true and the textbox does not lose the focus when clicking anywhere on the form.... except when clicking on a tab of a tab control...

Somehow the tab control seems to continue to work and switches pages, firing the validating event of the textbox a few times, but eventually losing the focus leaving an invalid value...

Does this make more sense?

 

by: TheLearnedOnePosted on 2003-12-30 at 08:23:01ID: 10016785

Are you still having a problem with this?

 

by: mshirePosted on 2003-12-31 at 11:19:22ID: 10023015

Yes I've still got the problem.

The validating event of a textbox doesn't seem to stop the tab control changing tabs... which is very annoying, any work around would be welcomed.

 

by: TheLearnedOnePosted on 2003-12-31 at 11:23:05ID: 10023030

I set up a small test (VB.NET 2003), with the tab control.  I put one text box, with e.Cancel = True in the TextBox_Validating event.  When I tried to change the tab page, it fired the Validating event, and cancelled, just like it is supposed to.  

 

by: TheLearnedOnePosted on 2004-01-06 at 14:01:08ID: 10056498

Did you get that last comment?  Did you find a fix yourself?

 

by: mshirePosted on 2004-01-07 at 01:58:09ID: 10060366

Thanks for your help it would appear that it was my problem, if you place sender.focus (I don't know why this was done....) in the validating event it causes the events I described above.

20120131-EE-VQP-002

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