I'm not sure what did you mean by "unbound value in Gridview", but one option to format fields in UI side will be to use
DataFormatString
property of
BoundField[
^]. For example
<asp:BoundField HeaderText="Price/Unit"
DataField="UnitPrice" SortExpression="UnitPrice"
DataFormatString="{0:c}">
will format UnitPrice field of the GridView to Currency. For lists of different DataFormatString ,have a look at
this[
^] MSDN article.