Return a generic from a static function

[Bill McCormick]

Hi C# programmers,

I'd like to be able to call a static function or property and have it
return a generic list. The compiler indicates that "static types cannot
be used as generic arguments", so I'm looking for the correct way to do
this and/or other alternatives.

The static function should make some DB query, build some objects
foreach record and populate a List<T>. In the end, I'd like to be able
to use it like this:

foreach(Item item in MyListFunction) DoSomethingWith (item);

I'd like to do this without having to first create a List and fill it
with whatever, so behind MyListFunction is the DB query, List creation,
object building and filling of the List.


Thanks,


Bill

[Anthony Jones]

Re: Return a generic from a static function

"Bill McCormick" <wpmccormick@ne wsgroup.nospamw rote in message
news:u0sDfz7MJH A.4380@TK2MSFTN GP04.phx.gbl...

Hi C# programmers,
>
I'd like to be able to call a static function or property and have it
return a generic list. The compiler indicates that "static types cannot be
used as generic arguments", so I'm looking for the correct way to do this
and/or other alternatives.
>
The static function should make some DB query, build some objects foreach
record and populate a List<T>. In the end, I'd like to be able to use it
like this:
>
foreach(Item item in MyListFunction) DoSomethingWith (item);
>
I'd like to do this without having to first create a List and fill it with
whatever, so behind MyListFunction is the DB query, List creation, object
building and filling of the List.
>
>

It would really help if you specify which version of C# you are using and
what version of framework you are targeting. C#3 pointing at .NET 3.5 then
this sort of thing is best handled with LINQ.

In C#2 you are probably don't want to return a List<Tbut an Enumerable<T>
and you should be looking at the yeild return statement.

The fact that you can't use a Static type as a generic argument is not
relevent, you're not looking for a method to return a set of static types
(which is an oxymoron) you are looking for a static method to return a set
of instances of a type.

State versions for more detail.


--
Anthony Jones - MVP ASP/ASP.NET

[Bill McCormick]

Re: Return a generic from a static function

Anthony Jones wrote:

"Bill McCormick" <wpmccormick@ne wsgroup.nospamw rote in message
news:u0sDfz7MJH A.4380@TK2MSFTN GP04.phx.gbl...

>Hi C# programmers,
>>
>I'd like to be able to call a static function or property and have it
>return a generic list. The compiler indicates that "static types
>cannot be used as generic arguments", so I'm looking for the correct
>way to do this and/or other alternatives.
>>
>The static function should make some DB query, build some objects
>foreach record and populate a List<T>. In the end, I'd like to be able
>to use it like this:
>>
>foreach(Item item in MyListFunction) DoSomethingWith (item);
>>
>I'd like to do this without having to first create a List and fill it
>with whatever, so behind MyListFunction is the DB query, List
>creation, object building and filling of the List.
>>
>>

>
It would really help if you specify which version of C# you are using
and what version of framework you are targeting. C#3 pointing at .NET
3.5 then this sort of thing is best handled with LINQ.
>
In C#2 you are probably don't want to return a List<Tbut an
Enumerable<Tand you should be looking at the yeild return statement.
>
The fact that you can't use a Static type as a generic argument is not
relevent, you're not looking for a method to return a set of static
types (which is an oxymoron) you are looking for a static method to
return a set of instances of a type.
>
State versions for more detail.
>
>

I'm using C#2. I'll take a look at yield.

Thanks.

[Bill McCormick]

Re: Return a generic from a static function

Bill McCormick wrote:

Anthony Jones wrote:

>"Bill McCormick" <wpmccormick@ne wsgroup.nospamw rote in message
>news:u0sDfz7MJ HA.4380@TK2MSFT NGP04.phx.gbl.. .

>>Hi C# programmers,
>>>
>>I'd like to be able to call a static function or property and have it
>>return a generic list. The compiler indicates that "static types
>>cannot be used as generic arguments", so I'm looking for the correct
>>way to do this and/or other alternatives.
>>>
>>The static function should make some DB query, build some objects
>>foreach record and populate a List<T>. In the end, I'd like to be
>>able to use it like this:
>>>
>>foreach(Ite m item in MyListFunction) DoSomethingWith (item);
>>>
>>I'd like to do this without having to first create a List and fill it
>>with whatever, so behind MyListFunction is the DB query, List
>>creation, object building and filling of the List.
>>>
>>>

>>
>It would really help if you specify which version of C# you are using
>and what version of framework you are targeting. C#3 pointing at .NET
>3.5 then this sort of thing is best handled with LINQ.
>>
>In C#2 you are probably don't want to return a List<Tbut an
>Enumerable<Tan d you should be looking at the yeild return statement.
>>
>The fact that you can't use a Static type as a generic argument is not
>relevent, you're not looking for a method to return a set of static
>types (which is an oxymoron) you are looking for a static method to
>return a set of instances of a type.
>>
>State versions for more detail.
>>
>>

I'm using C#2. I'll take a look at yield.
>
Thanks.

Compiler still gives me the same error ("static types

>>cannot be used as generic arguments").

for example:

public static class MyObjControl {

private static IEnumerable<MyO bjGetMyObjList( ) {
foreach(Foo foo in bar) {
MyObj myObj = new MyObj(foo);
yield return myObj;
}
}
}

[puzzlecracker]

Re: Return a generic from a static function

On Oct 21, 5:51 pm, Bill McCormick <wpmccorm...@ne wsgroup.nospam>
wrote:

Bill McCormick wrote:

Anthony Jones wrote:

"Bill McCormick" <wpmccorm...@ne wsgroup.nospamw rote in message
>news:u0sDfz7MJ HA.4380@TK2MSFT NGP04.phx.gbl.. .
>Hi C# programmers,

>

>I'd like to be able to call a static function or property and have it
>return a generic list. The compiler indicates that "static types
>cannot be used as generic arguments", so I'm looking for the correct
>way to do this and/or other alternatives.

>

>The static function should make some DB query, build some objects
>foreach record and populate a List<T>. In the end, I'd like to be
>able to use it like this:

>

>foreach(Item item in MyListFunction) DoSomethingWith (item);

>

>I'd like to do this without having to first create a List and fill it
>with whatever, so behind MyListFunction is the DB query, List
>creation, object building and filling of the List.

>

It would really help if you specify which version of C# you are using
and what version of framework you are targeting. C#3 pointing at .NET
3.5 then this sort of thing is best handled with LINQ.

>

In C#2 you are probably don't want to return a List<Tbut an
Enumerable<Tand you should be looking at the yeild return statement.

>

The fact that you can't use a Static type as a generic argument is not
relevent, you're not looking for a method to return a set of static
types (which is an oxymoron) you are looking for a static method to
return a set of instances of a type.

>

State versions for more detail.

>

I'm using C#2. I'll take a look at yield.

>

Thanks.

>
Compiler still gives me the same error ("static types

>>cannot be used as generic arguments").

>
for example:
>
public static class MyObjControl {
>
private static IEnumerable<MyO bjGetMyObjList( ) {
foreach(Foo foo in bar) {
MyObj myObj = new MyObj(foo);
yield return myObj;
}
}
>
}

Bill, I don't see anything wrong with code above. Would you point me
what breaks?

Thanks

[Bill McCormick]

Re: Return a generic from a static function

puzzlecracker wrote:

On Oct 21, 5:51 pm, Bill McCormick <wpmccorm...@ne wsgroup.nospam>
wrote:

>Bill McCormick wrote:

>>Anthony Jones wrote:
>>>"Bill McCormick" <wpmccorm...@ne wsgroup.nospamw rote in message
>>>news:u0sDfz7 MJHA.4380@TK2MS FTNGP04.phx.gbl ...
>>>>Hi C# programmers,
>>>>I'd like to be able to call a static function or property and have it
>>>>return a generic list. The compiler indicates that "static types
>>>>cannot be used as generic arguments", so I'm looking for the correct
>>>>way to do this and/or other alternatives.
>>>>The static function should make some DB query, build some objects
>>>>foreach record and populate a List<T>. In the end, I'd like to be
>>>>able to use it like this:
>>>>foreach(Ite m item in MyListFunction) DoSomethingWith (item);
>>>>I'd like to do this without having to first create a List and fill it
>>>>with whatever, so behind MyListFunction is the DB query, List
>>>>creation, object building and filling of the List.
>>>It would really help if you specify which version of C# you are using
>>>and what version of framework you are targeting. C#3 pointing at .NET
>>>3.5 then this sort of thing is best handled with LINQ.
>>>In C#2 you are probably don't want to return a List<Tbut an
>>>Enumerable<T and you should be looking at the yeild return statement.
>>>The fact that you can't use a Static type as a generic argument is not
>>>relevent, you're not looking for a method to return a set of static
>>>types (which is an oxymoron) you are looking for a static method to
>>>return a set of instances of a type.
>>>State versions for more detail.
>>I'm using C#2. I'll take a look at yield.
>>Thanks.

>Compiler still gives me the same error ("static types

> >>cannot be used as generic arguments").

>>
>for example:
>>
>public static class MyObjControl {
>>
> private static IEnumerable<MyO bjGetMyObjList( ) {
> foreach(Foo foo in bar) {
> MyObj myObj = new MyObj(foo);
> yield return myObj;
> }
> }
>>
>}

Bill, I don't see anything wrong with code above. Would you point me
what breaks?
>
Thanks

See my previous post.

Thanks.