accessing static members through Type?

[Rainer Queck]

Hi NG,

I have a generic list of Type where I hold some class types like:

List<Type> classList = new List<Type>();
classList.Add(typeof(Telegram1);
classList.Add(typeof(Telegram2);
......

Each of my Telegram<x> classes has a static Member "TlgNo";
With out building a instance of the class, I can get the TlgNo like
int tlgNo = Telegram1.TlgNo;

Is there a way to get this static member of the class from my list?
What I would like to do is:

for(int i=0; i<classList.Count; i++)
{
aTlgNo = classList[i].TlgNo;
......
}

Thanks for hints,

Rainer Queck

[Joanna Carter [TeamB]]

"Rainer Queck" <Ra****@noemail.noemail> a écrit dans le message de news:
uu**************@TK2MSFTNGP05.phx.gbl...

| I have a generic list of Type where I hold some class types like:
|
| List<Type> classList = new List<Type>();
| classList.Add(typeof(Telegram1);
| classList.Add(typeof(Telegram2);
| .....
|
| Each of my Telegram<x> classes has a static Member "TlgNo";
| With out building a instance of the class, I can get the TlgNo like
| int tlgNo = Telegram1.TlgNo;
|
| Is there a way to get this static member of the class from my list?
| What I would like to do is:
|
| for(int i=0; i<classList.Count; i++)
| {
| aTlgNo = classList[i].TlgNo;
| ......
| }

Assuming TlgNo is a static property, you need to use reflection like this :

foreach (object o in classList)
{
Type itemType = o.GetType();

PropertyInfo tlgNoProperty = itemType.GetProperty("TlgNo");
if (tlgNoProperty != null)
{
int aTlgNo = (int) tlgNoProperty.GetValue(null, null);
...
}
...
}

Joanna

--
Joanna Carter [TeamB]
Consultant Software Engineer

[Rainer Queck]

Hi Joanna,

thanks a lot for you help. Works perfect.

Rainer

[Göran Andersson]

A more object oriented solution could be to add an abstract property in
the base class and implement it in each class:

class Telegram {
abstract int TelegramNo { get; }
}

class Telegram1 : Telegram {
static int TlgNo = 1;
public virtual int TelegramNo { get { return TlgNo; } }
}

class Telegram2 : Telegram {
static int TlgNo = 2;
public virtual int TelegramNo { get { return TlgNo; } }
}

(It's my personal opinion that reflection generally is bad for program
structure. ;) )

Rainer Queck wrote:

Hi NG,

I have a generic list of Type where I hold some class types like:

List<Type> classList = new List<Type>();
classList.Add(typeof(Telegram1);
classList.Add(typeof(Telegram2);
.....

Each of my Telegram<x> classes has a static Member "TlgNo";
With out building a instance of the class, I can get the TlgNo like
int tlgNo = Telegram1.TlgNo;

Is there a way to get this static member of the class from my list?
What I would like to do is:

for(int i=0; i<classList.Count; i++)
{
aTlgNo = classList[i].TlgNo;
......
}

Thanks for hints,

Rainer Queck

[Joanna Carter [TeamB]]

"Göran Andersson" <gu***@guffa.com> a écrit dans le message de news:
%2****************@TK2MSFTNGP05.phx.gbl...

|A more object oriented solution could be to add an abstract property in
| the base class and implement it in each class:

....

| (It's my personal opinion that reflection generally is bad for program
| structure. ;) )

Unfortunately Rainer wanted to access the TlgNo value without having to
instantiate anything. Therefore, virtual properties/methods are not a viable
option.

Therefore, in the absence of virtual static members, the simplest choice is
reflection.

Joanna

--
Joanna Carter [TeamB]
Consultant Software Engineer

[Göran Andersson]

Aha, I see. When I look at the code again, I see that the List is only
containing the type of the objects, not any objects. Odd construction...
but in that case there is not much to do but to use reflection.

I didn't pay that much attention to the code as it isn't the actual code
that is used, as it won't even compile...

Joanna Carter [TeamB] wrote:

"Göran Andersson" <gu***@guffa.com> a écrit dans le message de news:
%2****************@TK2MSFTNGP05.phx.gbl...

|A more object oriented solution could be to add an abstract property in
| the base class and implement it in each class:

...

| (It's my personal opinion that reflection generally is bad for program
| structure. ;) )

Unfortunately Rainer wanted to access the TlgNo value without having to
instantiate anything. Therefore, virtual properties/methods are not a viable
option.

Therefore, in the absence of virtual static members, the simplest choice is
reflection.

Joanna