Generics and general purpose helpers

[Jeff Jarrell]

I am working with Winforms and writing some general purpose helpers for use
with a 3rd party grid (devexpress).

I have been using BindingList<Tto bind to the grid. At some point I need
to get the object stored at the Nth index of the list.

The intent is something like the following...
BindingList<Objectlist
list = (BindingList<Object>) gridview.DataSource
Object row = list[5]

The casts don't work because they are BindingList<ConcreteType>. I don't
know how to make the < ... part dynamic. And no, I can't use DataSets.

Suggestions?
jeff

[Nicholas Paldino [.NET/C# MVP]]

Jeff,

Cast the DataSource to IList (the non-generic version) and then access
it through that interface's indexer. You will get an object back, but I
assume that's fine, since you don't seem to know the type anyways (or can't
make assumptions about it in your code).

--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard.caspershouse.com

"Jeff Jarrell" <jj************@yahoo.comwrote in message
news:%2****************@TK2MSFTNGP02.phx.gbl...

>I am working with Winforms and writing some general purpose helpers for use
with a 3rd party grid (devexpress).

I have been using BindingList<Tto bind to the grid. At some point I
need to get the object stored at the Nth index of the list.

The intent is something like the following...
BindingList<Objectlist
list = (BindingList<Object>) gridview.DataSource
Object row = list[5]

The casts don't work because they are BindingList<ConcreteType>. I don't
know how to make the < ... part dynamic. And no, I can't use DataSets.

Suggestions?
jeff

[John B]

Jeff Jarrell wrote:

I am working with Winforms and writing some general purpose helpers for use
with a 3rd party grid (devexpress).

I have been using BindingList<Tto bind to the grid. At some point I need
to get the object stored at the Nth index of the list.

The intent is something like the following...
BindingList<Objectlist
list = (BindingList<Object>) gridview.DataSource
Object row = list[5]

The casts don't work because they are BindingList<ConcreteType>. I don't
know how to make the < ... part dynamic. And no, I can't use DataSets.

Suggestions?
jeff

public T ItemByIndex<T>(int index)
{
return ((BindingList<T>)gridview.DataSource)[index];
}

Or Nicholas's way :)

JB

[Jon Skeet [C# MVP]]

Jeff Jarrell <jj************@yahoo.comwrote:

I am working with Winforms and writing some general purpose helpers for use
with a 3rd party grid (devexpress).

I have been using BindingList<Tto bind to the grid. At some point I need
to get the object stored at the Nth index of the list.

The intent is something like the following...
BindingList<Objectlist
list = (BindingList<Object>) gridview.DataSource
Object row = list[5]

The casts don't work because they are BindingList<ConcreteType>. I don't
know how to make the < ... part dynamic. And no, I can't use DataSets.

Suggestions?

BindingList<Timplements IList - could you just cast to that instead?

--
Jon Skeet - <sk***@pobox.com>
http://www.pobox.com/~skeet Blog: http://www.msmvps.com/jon.skeet
If replying to the group, please do not mail me too

[Jeff Jarrell]

That did the trick. Thanks.

"Nicholas Paldino [.NET/C# MVP]" <mv*@spam.guard.caspershouse.comwrote in
message news:1D**********************************@microsof t.com...

Jeff,

Cast the DataSource to IList (the non-generic version) and then access
it through that interface's indexer. You will get an object back, but I
assume that's fine, since you don't seem to know the type anyways (or
can't make assumptions about it in your code).

--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard.caspershouse.com

"Jeff Jarrell" <jj************@yahoo.comwrote in message
news:%2****************@TK2MSFTNGP02.phx.gbl...

>>I am working with Winforms and writing some general purpose helpers for
use with a 3rd party grid (devexpress).

I have been using BindingList<Tto bind to the grid. At some point I
need to get the object stored at the Nth index of the list.

The intent is something like the following...
BindingList<Objectlist
list = (BindingList<Object>) gridview.DataSource
Object row = list[5]

The casts don't work because they are BindingList<ConcreteType>. I
don't know how to make the < ... part dynamic. And no, I can't use
DataSets.

Suggestions?
jeff