How do I validate the values entered for custom control properties?

21 Jul 2006 5:11 AM

Nathan Sokalski

I have a custom control with properties named MinValue, MaxValue, and Value
(all of which I have assigned a DefaultValue design-time attribute). The
Value property must be between (or equal to) the MinValue and MaxValue
properties in order to avoid a runtime error. I want to give an error during
the usage of the control stating this, as well as prevent it from compiling
under these conditions. Because this is something I have never done with
custom controls before, I need some help here. Thanks.

--
Nathan Sokalski
njsokal***@hotmail.com
http://www.nathansokalski.com/

21 Jul 2006 7:15 AM

G Himangi

One way would be to throw an exception if the value is out of range - Visual
Studio will catch this exception and not allow the user to change to invalid
values.

---------
- G Himangi, Sky Software http://www.ssware.com
Shell MegaPack : Drop-In Explorer GUI Controls For Your Apps (.Net & ActiveX
Editions Available)
EZNamespaceExtensions.Net : Develop namespace extensions rapidly in .Net
EZShellExtensions.Net : Develop all shell extensions rapidly in .Net
---------

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"Nathan Sokalski" <njsokal***@hotmail.com> wrote in message
news:Olw3uQIrGHA.4692@TK2MSFTNGP02.phx.gbl...
>I have a custom control with properties named MinValue, MaxValue, and Value
>(all of which I have assigned a DefaultValue design-time attribute). The
>Value property must be between (or equal to) the MinValue and MaxValue
>properties in order to avoid a runtime error. I want to give an error
>during the usage of the control stating this, as well as prevent it from
>compiling under these conditions. Because this is something I have never
>done with custom controls before, I need some help here. Thanks.
> --
> Nathan Sokalski
> njsokal***@hotmail.com
> http://www.nathansokalski.com/
>

21 Jul 2006 6:34 PM

Nathan Sokalski

That will not work in all situations. For example, if the current values are
MinValue=75, MaxValue=100, Value=80 and the user wants to change them to
MinValue=25, MaxValue=50, Value=40. This will force the user to change them
in a certain order, which could be very annoying. I want the user to be
notified, but still be allowed to change them, and simply not be allowed to
compile it if they are out of range. Also, if I did use your exception idea,
where in my code would I put it? Thanks.

--
Nathan Sokalski
njsokal***@hotmail.com
http://www.nathansokalski.com/

Show quoteHide quote

"G Himangi" <i***@ssware.com> wrote in message
news:empcjVJrGHA.3256@TK2MSFTNGP04.phx.gbl...
> One way would be to throw an exception if the value is out of range -
> Visual Studio will catch this exception and not allow the user to change
> to invalid values.
>
>
> ---------
> - G Himangi, Sky Software http://www.ssware.com
> Shell MegaPack : Drop-In Explorer GUI Controls For Your Apps (.Net &
> ActiveX Editions Available)
> EZNamespaceExtensions.Net : Develop namespace extensions rapidly in .Net
> EZShellExtensions.Net : Develop all shell extensions rapidly in .Net
> ---------
>
>
>
> "Nathan Sokalski" <njsokal***@hotmail.com> wrote in message
> news:Olw3uQIrGHA.4692@TK2MSFTNGP02.phx.gbl...
>>I have a custom control with properties named MinValue, MaxValue, and
>>Value (all of which I have assigned a DefaultValue design-time attribute).
>>The Value property must be between (or equal to) the MinValue and MaxValue
>>properties in order to avoid a runtime error. I want to give an error
>>during the usage of the control stating this, as well as prevent it from
>>compiling under these conditions. Because this is something I have never
>>done with custom controls before, I need some help here. Thanks.
>> --
>> Nathan Sokalski
>> njsokal***@hotmail.com
>> http://www.nathansokalski.com/
>>
>
>