Add protection mode that allows to make the document readonly, but allow forms editing. In MS Word this can be enabled via the "Restrict Editing" menu. The option is called "Filling in forms" and protects the document, but leaves the Sdt elements (the forms) editable.
We have a document in XLS format produced by GemBox. The yellow cells get black once the document is imported and then exported (back to XLS or XLSX) with RadSpreadProcessing.
The SUMIFS function adds all of its arguments that meet multiple criteria. A list of the supported functions is available at http://docs.telerik.com/devtools/document-processing/libraries/radspreadprocessing/features/formulas/functions This function can be implemented as a custom function. Check the following resources for more details on how to achieve that: - http://docs.telerik.com/devtools/document-processing/libraries/radspreadprocessing/features/formulas/custom-functions - https://github.com/telerik/xaml-sdk/tree/master/Spreadsheet/WPF/CustomFunctions
In the WPF Create New Project Wizard, the target framework versions dropdown is empty when no distribution is installed: