extending system class

[active T]

Is it possible to extend the system classes?

I want to create a function for converting a DateTime into a TimeSpan.

Any Ideas?

at the moment i've created:

public class Convert
{
public static TimeSpan DateTimeToTimeS pan(DateTime value)
{
return new TimeSpan(value. Hour, value.Minute,
value.Second);
}
}


But I like a funtction like:

DateTime inputVar
Timestamp outputVar= inputVar.GetTim eStamp


is this possible? Just extending the systemclass.

thnx

[Jon Skeet [C# MVP]]

Re: extending system class

On Oct 23, 2:03 pm, active T <TonnyBr...@gma il.comwrote:

Is it possible to extend the system classes?
>
I want to create a function for converting a DateTime into a TimeSpan.
>
Any Ideas?

<snip>

Well, there are three points here:

1) DateTime and TimeSpan are both structs, not classes, and therefore
can't be derived from.
2) You can't really add methods to an existing type
3) Extension methods in C# 3 make it *look* like you're adding methods
- you could do what you want with C# 3.

Jon

[Martin Honnen]

Re: extending system class

active T wrote:

Is it possible to extend the system classes?

Will be possible in the upcoming version of C#/.NET:
<URL:http://weblogs.asp.net/scottgu/archive/2007/03/13/new-orcas-language-feature-extension-methods.aspx>



--

Martin Honnen --- MVP XML
http://JavaScript.FAQTs.com/

[Ignacio Machin \( .NET/ C# MVP \)]

Re: extending system class

Hi,


You cannot extend an already defined class (will be possible in the next
version though). You could derive from it but then you need to make
reference to your own class.
Unfortunatelly Convert is marked as sealed so you cannot inherit from it.

In your particular case, I do not see how you will do it. A DateTime and a
TimeSpan represent two different concepts.You cuold only do it IF you set a
starting point only then you could do a TimeSpan.
What would be your starting point ?

--
Ignacio Machin

http://www.laceupsolutions.com

Mobile & warehouse Solutions.
"active T" <TonnyBrink@gma il.comwrote in message
news:1193144612 .674320.80700@k 35g2000prh.goog legroups.com...

Is it possible to extend the system classes?
>
I want to create a function for converting a DateTime into a TimeSpan.
>
Any Ideas?
>
at the moment i've created:
>
public class Convert
{
public static TimeSpan DateTimeToTimeS pan(DateTime value)
{
return new TimeSpan(value. Hour, value.Minute,
value.Second);
}
}
>
>
But I like a funtction like:
>
DateTime inputVar
Timestamp outputVar= inputVar.GetTim eStamp
>
>
is this possible? Just extending the systemclass.
>
thnx
>

[Christof Nordiek]

Re: extending system class

"active T" <TonnyBrink@gma il.comschrieb im Newsbeitrag
news:1193144612 .674320.80700@k 35g2000prh.goog legroups.com...

Is it possible to extend the system classes?
>
I want to create a function for converting a DateTime into a TimeSpan.

<snip>

at the moment i've created:
>
public class Convert
{
public static TimeSpan DateTimeToTimeS pan(DateTime value)
{
return new TimeSpan(value. Hour, value.Minute,
value.Second);
}
}
>
>

Besides, that this omits seconds fractions, it's the same as TimeOfDay, wich
allready is in DateTime.

Christof