IDbDataParameter参数转换的问题, 一直困惑.

Private Shared Function getSQLParameter(ByVal ParamArray commandParameters() As IDbDataParameter) As SqlParameter()
Dim i As Integer
Dim newParamter() As SqlParameter
If Not (commandParameters Is Nothing) Then
If commandParameters.Length > 0 Then
ReDim newParamter(commandParameters.Length - 1)
For i = 0 To commandParameters.Length - 1
newParamter(i) = CType(commandParameters(i), SqlParameter)
Next
End If
Else
newParamter = CType(Nothing, SqlParameter())
End If
Return newParamter
End Function

现在用C#写, 我想知道 CType(commandParameters(i), SqlParameter) 应该怎么写,谢谢!