How to pass a typed dataset to a web service

[Justin Crossley]

I'm having a type mismatch problem when trying to pass a typed dataset to a
web service.

My code is:

CLIENT CODE

I have a dataset schema file called MainData.xsd containing a table called
mytable

'create and fill typed dataset
Dim dsMain As New MainData
Dim con As New SqlConnection("myconnectionstring")
Dim da As New SqlDataAdapter("select * .....", con)
da.Fill(dsMain.mytable)

'pass typed dataset to web service
Dim ws As New localhost.DataTransfer
ws.PassData(dsMain)

WEB SERVICE CODE

The web service also has an identical local file containing the data schema
called MainData.xsd

<WebMethod()> Public function PassData(Value as MainData)
....
End Function
Unfortunately I get an error when I hover over the PassData method that says
'Value of Type MainData cannot be converted to localhost.MainData'.

It is obviously treating the two data types as being different.

If I change the parameter type of the PassData function to type DataSet then
the function can be called OK, but then I lose the type information.

Any ideas anybody?

Thanks

Justin Crossley

[Drew Marsh]

Justin Crossley wrote:

I'm having a type mismatch problem when trying to pass a typed dataset
to a web service.

... code snipped for brevity ...

Unfortunately I get an error when I hover over the PassData method
that says 'Value of Type MainData cannot be converted to
localhost.MainData'.

It is obviously treating the two data types as being different.
It's because they are two different data types as far as .NET knows. Even though the MainData you have generated on the client is logically the same because it was generated from the same XSD, it's not the same .NET type. So you have to use the MainData class generated by the web reference.
If I change the parameter type of the PassData function to type
DataSet then the function can be called OK, but then I lose the type
information.

Yeah, you shouldn't have to go this route though. It's less type specific and what you're doing is a perfectly viable solution. I think you're just getting confused by .NET typing vs. XSD typing.

HTH,
Drew