Charts in excel have support for minor grid lines. This is not supported here.

Stacktrace: 

Now there is no public API that allows the users to check if a Worksheet is empty or not. The UsedCellRange property returns a cell range that is only the cell A1 even if it is empty too.

Possible solution is to expose IsEmpty property of the CellRange.

Workaround: Check if Worksheet.UsedCellRange contains only A1, and that additionally A1 is empty.

The value of Worksheet.UsedCellRange could be calculated during the import of the workbook - as all cells are processed anyway. This will improve the performance of the first usage of this property, which is very common scenario. Also xlsx documents can have optional 'dimension' element which is used to specify the used cell range:

<dimension ref="A1:C2"/>.

Introduce support for cell reference ranges which refer to whole columns. For example "=Sheet1$A:$A" refers to the whole column A.

Create API allowing conversion of .NET standard numeric format strings to Excel/RadSpreadsheet's number formats.

For example, G3 .NET numeric format should be converted to scientific notation RadSpreadsheet mode - CellValueFormat("0.00E+00").

Include the view property in the model in order to not be lost during import and export. The possible values for this property are normal, pageBreakPreview, and pageLayout.

Example:
<sheetViews>
    <sheetView tabSelected="1" view="pageBreakPreview" zoomScaleNormal="100" zoomScaleSheetLayoutView="100" workbookViewId="0">
        <selection activeCell="J5" sqref="J5"/>
    </sheetView>
</sheetViews>

When a chart is inserted in a document, generated by SpreadProcessing or WordsProcessing, the chart seems to lack any bars. The reason is that some theme information is missing, which effectively makes shapes take their default color, which is transparent. The same applies for shapes inserted in any Document Processing-generated OOXML documents - docx, xlsx.

Workaround: (applicable for Excel) Manually change the theme for the document in MS Excel:
- Choose Page Layout -> Themes -> Themes dropdown -> Office.

Add support for theme effects (format schemes). They are described in OOXML using the 'fmtScheme' element. Thing of providing predefined sets.

In MS Excel the UI for changing is located in Page Layout tab -> Themes -> Effects.

Split allows you to split the window into different panes that each scroll separately. 

This feature is different than the horizontal/vertical split of freeze panes, which is supported.

When importing and exporting xlsx document with email address hyperlink the exported document shows invalid document message when opened in Excel: "We found a problem with some content in 'file.xlsx'. Do you want us to try to recover as much as we can? If you trust the source of thes workbook, click Yes.". The document can be only partially recovered and information is lost.

Steps to reproduce: 

1. Enter in a cell =Today()
2. Show Format Cells dialog and set Custom format "d"

Expected: The value is the day of the month.
Actual: The date is formatted as short date but has to be day of the month.

Add API for registering custom image decoders, e.g. for .emf and .wmf images.

Add support for the AVERAGEIF function:  https://support.office.com/en-us/article/AVERAGEIF-function-faec8e2e-0dec-4308-af69-f5576d8ac642

Returns the average (arithmetic mean) of all the cells in a range that meet a given criteria:

AVERAGEIF(range, criteria, [average_range])


Workaround: This could be implemented as a custom function: http://docs.telerik.com/devtools/document-processing/libraries/radspreadprocessing/features/formulas/custom-functions.html

The exception is thrown when importing a document that contains an empty stylesheet tag in its styles.xml part.

For example, if a user wants to set a 5x5 array of values in the worksheet he has to iterate through all the values one by one and set it to the worksheet. With that API the user should be able to set the entire array with just one method call giving it the array.

When calling AutoFitWidth on single cell selections there is no issue. However, calling it on a multi-column selection the document is corrupted and repair error message is shown when opening it in Excel.

Workaround: The AutoFitWidth method may be called for each column separately. 

If Spreadsheet's history is not enabled, merged cells cannot be unmerged. 

Workaround: Enable the History before calling Unmerge():

workbook.History.IsEnabled = true;
worksheet.Cells[0, 0, 0, 4].Unmerge();
workbook.History.IsEnabled = false;

This would allow repeating header rows on every printed page. More information related to this functionality may be found on the following link:

https://support.office.com/en-us/article/Print-rows-with-column-headers-on-top-of-every-page-d3550133-f6a1-4c72-ad70-5309a2e8fe8c

Add support for TRIM function. TRIM removes all spaces from text except for single spaces between words.

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/CustomFunctions

Available in R2 2017 Official Release.