DateTime null

[JJ]

Hi,

What's the correct code for checking if a DateTime control is empty or not
filled in with a date?

Thanks,

JJ

[Jon Skeet [C# MVP]]

Re: DateTime null

JJ <JJ@discussions .microsoft.com> wrote:[color=blue]
> What's the correct code for checking if a DateTime control is empty
> or not filled in with a date?[/color]

Not sure what you mean by a DateTime control, as DateTime *isn't* a
control - however, there's no concept of a DateTime not being filled
in, any more than there is a concept of an int not being filled in. You
*may* be able to use a special value (eg DateTime.MinVal ue) as "not
provided" depending on your application.

Alternatively, you could encapsulate the DateTime in a reference type.

--
Jon Skeet - <skeet@pobox.co m>

http://www.pobox.com/~skeet

If replying to the group, please do not mail me too

[Bruce Wood]

Re: DateTime null

Or, you could wait for v2.0 of the Framework, at which point you can
use "DateTime?"

[JJ]

Re: DateTime null

ok the DateTimePicker Control is what i'm using if u want to get technical
about it.
I want to know if someone has not entered a date into it.

JJ

"Jon Skeet [C# MVP]" wrote:
[color=blue]
> JJ <JJ@discussions .microsoft.com> wrote:[color=green]
> > What's the correct code for checking if a DateTime control is empty
> > or not filled in with a date?[/color]
>
> Not sure what you mean by a DateTime control, as DateTime *isn't* a
> control - however, there's no concept of a DateTime not being filled
> in, any more than there is a concept of an int not being filled in. You
> *may* be able to use a special value (eg DateTime.MinVal ue) as "not
> provided" depending on your application.
>
> Alternatively, you could encapsulate the DateTime in a reference type.
>
> --
> Jon Skeet - <skeet@pobox.co m>
> http://www.pobox.com/~skeet
> If replying to the group, please do not mail me too
>[/color]

[mk]

Re: DateTime null

Incidentally, how would you set the value to null in the first place? I
would recommend that you handle the click or valuechanged event to indicate
user interaction.
BTW: The venerable Mr. Skeet was exactly right in pointing you towards
reference type, not to mention that he similar to the C# forum what
Alexander, Kim, Brian, and Igor are to the ATL forum (sorry
gurus-not-mentioned, I'm very bad on names). Suggesting that a person is
being too technical in a technical forum may be ill-received by some people.
Best regards.

HTH,

mk

"JJ" wrote:
[color=blue]
> ok the DateTimePicker Control is what i'm using if u want to get technical
> about it.
> I want to know if someone has not entered a date into it.
>
> JJ
>
> "Jon Skeet [C# MVP]" wrote:
>[color=green]
> > JJ <JJ@discussions .microsoft.com> wrote:[color=darkred]
> > > What's the correct code for checking if a DateTime control is empty
> > > or not filled in with a date?[/color]
> >
> > Not sure what you mean by a DateTime control, as DateTime *isn't* a
> > control - however, there's no concept of a DateTime not being filled
> > in, any more than there is a concept of an int not being filled in. You
> > *may* be able to use a special value (eg DateTime.MinVal ue) as "not
> > provided" depending on your application.
> >
> > Alternatively, you could encapsulate the DateTime in a reference type.
> >
> > --
> > Jon Skeet - <skeet@pobox.co m>
> > http://www.pobox.com/~skeet
> > If replying to the group, please do not mail me too
> >[/color][/color]

[JJ]

Re: DateTime null

What I meant was there is a datetimepicker control. Sorry for leaving off the
picker part but I figured most people would know that I'm probably talking
about the datetimepicker control.

"mk" wrote:
[color=blue]
> Incidentally, how would you set the value to null in the first place? I
> would recommend that you handle the click or valuechanged event to indicate
> user interaction.
> BTW: The venerable Mr. Skeet was exactly right in pointing you towards
> reference type, not to mention that he similar to the C# forum what
> Alexander, Kim, Brian, and Igor are to the ATL forum (sorry
> gurus-not-mentioned, I'm very bad on names). Suggesting that a person is
> being too technical in a technical forum may be ill-received by some people.
> Best regards.
>
> HTH,
>
> mk
>
> "JJ" wrote:
>[color=green]
> > ok the DateTimePicker Control is what i'm using if u want to get technical
> > about it.
> > I want to know if someone has not entered a date into it.
> >
> > JJ
> >
> > "Jon Skeet [C# MVP]" wrote:
> >[color=darkred]
> > > JJ <JJ@discussions .microsoft.com> wrote:
> > > > What's the correct code for checking if a DateTime control is empty
> > > > or not filled in with a date?
> > >
> > > Not sure what you mean by a DateTime control, as DateTime *isn't* a
> > > control - however, there's no concept of a DateTime not being filled
> > > in, any more than there is a concept of an int not being filled in. You
> > > *may* be able to use a special value (eg DateTime.MinVal ue) as "not
> > > provided" depending on your application.
> > >
> > > Alternatively, you could encapsulate the DateTime in a reference type.
> > >
> > > --
> > > Jon Skeet - <skeet@pobox.co m>
> > > http://www.pobox.com/~skeet
> > > If replying to the group, please do not mail me too
> > >[/color][/color][/color]

[Jon Skeet [C# MVP]]

Re: DateTime null

JJ <JJ@discussions .microsoft.com> wrote:[color=blue]
> What I meant was there is a datetimepicker control. Sorry for leaving off the
> picker part but I figured most people would know that I'm probably talking
> about the datetimepicker control.[/color]

As far as I can see, a DateTimePicker is filled with the current
date/time until the user chooses something, so there's no concept of
"null" there either.

--
Jon Skeet - <skeet@pobox.co m>

http://www.pobox.com/~skeet

If replying to the group, please do not mail me too

[Claudio Grazioli]

Re: DateTime null

On Wed, 11 May 2005 13:59:15 -0700, JJ wrote:
[color=blue]
> What I meant was there is a datetimepicker control. Sorry for leaving off the
> picker part but I figured most people would know that I'm probably talking
> about the datetimepicker control.
>[/color]

With the standard DateTimePickerC ontrol a user does not have the
possibility to enter no date. So you always have a valid DateTime value in
the DateTimePickerC ontrol.

If you need a DateTimePickerC ontrol that allows the user to empty the
control, have a look at this solution:

http://www.codeproject.com/cs/miscctrl/NullableDateTimePicker.asp

--
Claudio Grazioli

http://www.grazioli.ch

http://www.grazioli.ch/HommingbergerGepardenforelle/