Hi,
The following code throws me an Error, i use a method to bring a DataTable
object and i want to asigne it to a Strongly Typed DataTable, but VB doesn't
allow me.
How can i do this right? And if it couldn't be done, then wich would be an
equivalent solution.
Thank you very much.


'FoldersDataTable: Inherits from DataTable.
Dim Data As New FoldersDataTable

'BringDataTable: Retrives a DataTable object
Data = CType(BringDataTable("Select * From Folders"), FoldersDataTable)
'Error: 'InvalidCastExeption'

> Hi,
> The following code throws me an Error, i use a method to bring a
> DataTable
> object and i want to asigne it to a Strongly Typed DataTable, but VB
> doesn't
> allow me.
> How can i do this right? And if it couldn't be done, then wich would
> be an
> equivalent solution.
> Thank you very much.
> 'FoldersDataTable: Inherits from DataTable.
> Dim Data As New FoldersDataTable
> 'BringDataTable: Retrives a DataTable object
> Data = CType(BringDataTable("Select * From Folders"),
> FoldersDataTable)
> 'Error: 'InvalidCastExeption'

Right, you are trying to do an upcast essentially, which is never permissable.

You have a few options (OTTOMH):
1) Fill the super data table directly.
2) Copy the data from one to the other.

Obviously 1 will be more performant than 2 but depending on your circumstances
may not be possible.

hth, Ryan

Thanks for your answer,
In my case y can fill the strongly typed DataTable as you've suggested, but
the thing is that right now i am learning this kind of "stuff" (i mean
ADO.NET) while building my application, so i allready have set a proyect for
manipulating data, and i have set al methods in the classes of this proyect
to return DataSet and DataTable objects to use in the buisennes ruels
proyect, so I do want to follow your sugestion of filling directly the
strongly typed DataTable, but how do i arrange the hole design of the tiers.



"Ryan Trudelle-Schwarz" <(E-Mail Removed)> escribió en el mensaje
news:(E-Mail Removed)...
>> Hi,
>> The following code throws me an Error, i use a method to bring a
>> DataTable
>> object and i want to asigne it to a Strongly Typed DataTable, but VB
>> doesn't
>> allow me.
>> How can i do this right? And if it couldn't be done, then wich would
>> be an
>> equivalent solution.
>> Thank you very much.
>> 'FoldersDataTable: Inherits from DataTable.
>> Dim Data As New FoldersDataTable
>> 'BringDataTable: Retrives a DataTable object
>> Data = CType(BringDataTable("Select * From Folders"),
>> FoldersDataTable)
>> 'Error: 'InvalidCastExeption'
>
> Right, you are trying to do an upcast essentially, which is never
> permissable.
>
> You have a few options (OTTOMH):
> 1) Fill the super data table directly.
> 2) Copy the data from one to the other.
>
> Obviously 1 will be more performant than 2 but depending on your
> circumstances may not be possible.
>
> hth, Ryan
>

Anibal,

What is the returntype of
BringDataTable("Select * From Folders")

Cor

The type is a DataTable Object with the data from the SQL statement

"Cor Ligthert" <(E-Mail Removed)> escribió en el mensaje
news:(E-Mail Removed)...
> Anibal,
>
> What is the returntype of
> BringDataTable("Select * From Folders")
>
> Cor
>