How do I extend the DBProviderFactory class to accept parameters?

I am writing an ASP.NET 2.0 app. I need touse several databases, so I am using the DbProviderFactory to I can dynamically change the provider type. Although it works, I find the parameter adding a bit verbose. Because the createParameter method doesn't accept parameters itself, I end up with several lines of code like this for each parameter....

    param = oFactory.CreateParameter()
    param.ParameterName = "ID"
    param.DbType = DbType.Int32
    param.Value = 2

What I am trying to do is extend the DbProviderFactory to include a CreateParameter method that DOES accept these properties as parameters. Here is what I have...

Public Class ExtendedDbProviderFactory Inherits DbProviderFactory

Public Function CreateMyParameter(ByVal strParameterName As String, ByVal oDBType As DbType, ByVal oValue As Object) As System.Data.Common.DbParameter

    Dim param As System.Data.Common.DbParameter
    param = MyBase.CreateParameter()

    param.ParameterName = strParameterName
    param.DbType = oDBType
    param.Value = oValue

    Return param

End Function

End Class

I then attempt to create it using this code....

    Dim css As System.Configuration.ConnectionStringSettings = ConfigurationManager.ConnectionStrings(0)
    Dim oMyExtendedFactory As ExtendedDbProviderFactory = DbProviderFactories.GetFactory(css.ProviderName)

But I keep getting this error when I run it with a SQL Server provider

Unable to cast object of type 'System.Data.SqlClient.SqlClientFactory' to type 'ExtendedDbProviderFactory'.

I would think that, because my class inherits the DBProviderFacotry class, and only extends it with 1 method, it would work as easily as the DBProviderFactory class itself does.

ansaurus

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How do I extend the DBProviderFactory class to accept parameters?

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