How to Validate the Editing Field Value in the Document Preview
This example demonstrates how to validate the EditingField value before closing the Editing Field editor, and how to prevent the editor from opening for certain fields.
Analyze the field value in the DocumentPreviewControl.ValidateEditingField event handler. If validation fails, set the IsValid property to false and specify the ErrorType and ErrorMessage property values.
Handle the DocumentPreviewControl.ShowingEditingFieldEditor event, determine the field by checking the EditingField property, and set the Cancel property to true to prevent the editor for that field from being displayed.