I have the following SqlDataSource and I want to convert it to DataView and read a column from it:
The SqlDataSource has a Select method which you can call to get back a DataView from your SqlDataSource - see the MSDN documentation on that.
SqlDataSource dataSource = new SqlDataSource(connectionString, selectSql);
DataView view = (DataView)dataSource.Select(args);
DataTable table = view.ToTable();
Is that what you're looking for??