Editing Calculated Expression
You can allow users to edit or create new custom expressions in the Expression Editor at runtime. To accomplish this, set the PivotGridFieldOptionsEx.ShowExpressionEditorMenu property to true to add the Expression Editor command to the field’s context menu or call the ShowExpressionEditor method to invoke the Expression Editor.
Note
You cannot use the Expression Editor dialog in OLAP mode.
To switch to a new version of the Expression Editor, set the ExpressionEditorMode property to ExpressionEditorMode.AutoComplete.
For information on the syntax of expressions, see Expressions.
Refer to the Bind Pivot Grid Fields to Calculated Expressions topic for information on how to create calculated fields and populate them with data.