LocalizableException with text "Format string is not in the correct format.", with inner ArgumentException "Format string is not in the correct format." is thrown. 

Currently the validation doesn't allow number format string starting with date or time formatting to have more that one section (for negative and zero numbers). Excel allows this type of number formats and if you set format like dd/mm/yyyy;[RED](#.##0); the positive numbers are visualized as dates, but negative numbers are visualized as numbers and their fore color is red.

Examples (including the final semicolons):

- ss;

- dd;

- dd/mm/yyyy;;

- mmm-yy;mmm-yy;_-* "-"??_-;_-@_-

When number format ends with N commas, the resulting number should be divided to 1000 N times. Instead, such commas are ignored. 

For example, if the format is #.0,, and the value of the cell is 12,200,000, the number should be displayed as 12.200.0

Improve the editing in RadSpreadsheet with IME (input method editors). 

Problematic scenarios:

- Start typing:
When Japanese IME is chosen (for example) and the user starts typing while a cell is selected, the CellEditor should be in EditMode - the same behavior as if you are typing in English.

- Committing:
When the user is already in EditMode and typing with the Japanese IME, suggestions are listed in a popup. The user can than commit the sentence by selecting some of the suggested words with the mouse (by double-clicking on the suggestion) everything is correct and you continue to be in EditMode. However, if the user navigates to the suggestion and hit Enter (which is the most used case and it is somehow the native one) the editor goes out from EditMode to Inactive.

Data validation does not validate values if they are not set using the cell editor. Pasting or auto-fill of invalid values will not produce data validation warning.

The formula expressions are invalidated by the formula arguments only. Which means that the formula expression will be invalidated only if some of its arguments is invalidated. But formulas like Indirect returns cell reference ranges. If something in the preferred range is changed the result have to update for which invalidation of the formula expression is needed.

Using SetValueAsText method to set empty string and the exporting the document generates invalid XLSX, which can not be imported by Excel.

Currently indexed colors are imported only regarding the default color palette. Instead, when the entire palette is predefined using construct like:

  <colors>
    <indexedColors>
      <rgbColor rgb="00000000"/>
      ...

in styles.xml part, the indexed should be changed with the provided ones.

As this feature is not implemented, such colors are changed during the import.

RadSpreadsheet should respect negative time values as MS Excel does it.

Add an event that indicates when a hyperlink is clicked.

Xlsx documents with a global filter defined cannot be imported. Message box "The name that you entered is not valid." is shown and internally SpreadsheetNameException is thrown. MS Excel can import such document and even preserve the filter, but do not respect it and doesn't have UI to clear it.

Workaround 1 (includes processing the document with MS Excel):
- Open the document in MS Excel
- Choose Formulas -> Defined names -> Named Manager
- Choose Filter -> Names with errors
- Find all Filter defined names and delete them
- Save the document

Returns a Range object that represents the current region. The current region is a range bounded by any combination of blank rows and blank columns. If we want to be consistent with MS Excel we should implement this property. It is useful for many operations of a region such as filtering(selecting one cell and executing the Filter command should apply it to the current region), sorting, selecting all and etc. This document will be useful: https://docs.microsoft.com/en-us/office/vba/api/excel.range.currentregion.

Filter command should be disabled when a single row or cell is selected. 

Fix available in LIB Version 2018.3.1105.

Customers are reporting an issue when trying to copy content in an application hosted on a remote machine (there are reports using TigerVNC and Citrix).  The exception is thrown from the Clipboard class with a message: OpenClipboard failed (Exception from HRESULT: 0x800401D0 (CLIPBRD_E_CANT_OPEN))

It seems like such a behavior could be reproduced when the clipboard is already opened by another application. Here is a discussion on the matter: https://stackoverflow.com/questions/68666/clipbrd-e-cant-open-error-when-setting-the-clipboard-from-net

The functionality would allow to zoom the print preview and scroll the resulting viewport.

A partial implementation of the zooming functionality can be found in the attached file to provide a starting point for a custom implementation.

The PrintPreviewControl refreshes its preview content on change in the SheetPageSetup object. This method would allow on-demand update.

At the moment this can be achieved by changing something in the page setup and restoring it. 

bool printGridlines = this.spreadsheet.Workbook.ActiveWorksheet.WorksheetPageSetup.PrintOptions.PrintGridlines;
this.spreadsheet.Workbook.ActiveWorksheet.WorksheetPageSetup.PrintOptions.PrintGridlines = !printGridlines;
this.spreadsheet.Workbook.ActiveWorksheet.WorksheetPageSetup.PrintOptions.PrintGridlines = printGridlines;

This behavior happens at a specific width of the cell's Column. Using different VerticalAlignment (not Bottom) would workaround this issue.

When the formula bar is empty and alt + enter is pressed in order to insert a new line, NullReferenceException is thrown. The exception might be reproduced with text in the formula bar, but the caret has to be placed in the end of a run/end of the text.

Fix available in LIB Version 2018.2.820.

In MS Excel, the users can choose between showing the original size of the page and fit it in the window. Expose a similar option in RadSpreadsheet as well.

When the users click on the More Borders option provided in the ribbon UI, the Format Cells dialog opens but the popup of the dropdown is still kept open.