How to retrieve value of a field in a dataset

VB.NET

ds.Tables('TableName').Rows(0)('ColumnName')

C#

ds.Tables['TableName'].Rows[0]['ColumnName'];

where TableName and ColumnName could be also integer (not in quotes then) to indicate you refer to the table’s or column’s index position.
Rows(0) indicates the first and only row in DataTable’s Rows collection