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

Resizing images always position the image at the cell where the image has been inserted. Flipping image also results in a wrong behavior.

Add support for formats which can present numbers with non-arabic numerals, for example:
- Bengali - [$-bn-IN,500]0
- Devanagari - [$-hi-IN,400]0
- East Arabic - [$-ar-SA,200]0
- Persian - [$-ar-SA,300]0
- Gujarati - [$-gu-IN,700]0
- Kannada - [$-kn-IN,B00]0
- Khmer - [$-et-EE,1200]0
- Lao - [$-lo-LA,E00]0
- Malayalam - [$-ml-IN,C00]0
- Mongolian - [$-mn-MN,1300]0
- Burmese - [$-my-MM,1000]0
- Oriya - [$-or-IN,800]0
- Tamil - [$-ta-IN,900]0
- Telugu - [$-te-IN,A00]0
- Thai - [$-th-TH,D00]0
- Tibetan - [$-bo-CN,F00]0

The item is closed as a duplicate. Please, vote and follow the item at https://feedback.telerik.com/wpf/1354143-spreadsheet-add-support-for-number-formats-for-presenting-numbers-with-non-arabic-numerals.

When you chose the Expand XAML option of the RadSpreadsheetRibbon control, the Charts group which should be in the Insert tab, is missing.

Add support for visualizing and editing charts.

Some of the RadSpreadsheet child controls do not apply the new theme, but stay with office black applied when theme is set on control level.

ArgumentException is thrown when protecting a worksheet having missing algorithmName information

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

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

At the moment when any of the properties are changed, e.g. the frozen panes, the UI is not notified and you have to export and import the file in order for the UI to pick them up. 


Workaround: There are several workarounds:

1. Change the active worksheet and return to the old one

2. Export and import the document

3. Change the workbook of the RadSpreadsheet to a new one, and return the old one after that
4. Freeze the active worksheet using the ActiveWorksheetEditor.FreezePanes() method and freeze all others using the ViewState:
RadWorksheetEditor editor = this.radSpreadsheet.ActiveWorksheetEditor;
editor.FreezePanes(new CellIndex(3,3));
foreach (var worksheet in this.radSpreadsheet.Workbook.Worksheets)
{
    worksheet.ViewState.FreezePanes(5, 5);
}

We should provide an easier API allowing the customers to remove the key bindings or change the commands that they trigger.

Workaround: There is attached a sample showing how all the commands triggered by the key bindings can be disabled.

The AM/PM value is not shown in the cell when formatting a time value.

Steps to reproduce:
1. Insert some time in a cell in spreadsheet (22:20)
2. Apply it a custom format that contains AM/PM (e.g. "h:mm AM/PM")

Observed: The AM/PM format is missing
Expected: AM or PM should be shown after the time (image attached) 

Declined: The changes could be applied if the user presses OK button instead of pressing Enter key. A new feedback item is open where the issue is described: https://feedback.telerik.com/Project/143/Feedback/Details/212042-spreadsheet-custom-number-type-values-in-format-cells-dialog-are-not-applied-wh

If plain text is pasted in a cell, and the text is automatically recognizable as date, number, percentage, formula or other format, the text is always converted to the recognized number format.

Instead, the cell's current number format should affect the convertion in the following way:
- If the current format is General -> parse the value with the automatically recognized format, and set the value with the automatically recognized format
- If the current format is Text -> set the value as text, and preserve the current format (Text)
- If the current format is any other format -> try parse the value with the current format
  - Successful -> set the parsed value with the current format
  - Unsuccessful -> parse the value with the automatically recognized format, and set the parsed value with the current format.

As a result, strings which are recognizable as dates, for example, are pasted as their numeric representation instead of with their Date formatting. Also it's not possible to paste something as plain text. 

Workaround: for always pasting plain text: Create custom Paste button and executes the following code:
this.radSpreadsheet.ActiveWorksheetEditor.Selection.Cells.SetValueAsText(Clipboard.GetText());

When setting the following strings as cell value, they are recognized as dates. In industry standard applications like MS Excel and OpenOffice, they are recognized as strings:
- "12 3456" in bg-BG, fr-FR, ru-RU, sv-FI, en-US
- "12.3456" in de-DE
- "1 23" in en-US
- "2013/5" in en-US
- "3000-03" in en-US

Currently the following text filters are not supported in the model, filtering popup and Custom Filter dialog:
- begins with
- does not begin with
- ends with
- does not end with
- contains
- does not contain.

All of these are supported in MS Excel.

Add support for import and export of Excel Template files (XLTS) file format.

The overlapping of SelectionFill and SelectionStroke geometries may be seen in the attached screenshot. This scenario may be reproduced with the following RadSpreadsheet instance:

<telerik:RadSpreadsheet SelectionStroke="Red" SelectionStrokeThickness="10" FillHandleSelectionStroke="Green" SelectionFill="#550000FF" />

Number formats like "[$-1010409]General" containing locale code and General keyword are not parsed correctly which results in interpreting them as number formats which have to replace the positive numbers with "General".

Available in R1 2017 SP

The visualization and scrolling of documents containing many merged cells (e.g. 1000) is very slow. The control becomes almost unusable when the number increases.

Workaround: Import the document without using the default command

OpenFileDialog openFileDialog = new OpenFileDialog();
openFileDialog.Filter = "All Spreadsheet Files (*.txt, *.csv, *.pdf, *.xlsx)|*.txt;*.csv;*.pdf;*.xlsx|Excel Workbook (*.xlsx)|*.xlsx|CSV (Comma delimited) (*.csv)|*.csv|Text (Tab delimited) (*.txt)|*.txt|All Files (*.*)|*.*";
if (openFileDialog.ShowDialog() == true)
{
    string extension = Path.GetExtension(openFileDialog.SafeFileName);
    using (Stream input = openFileDialog.OpenFile())
    {
        Workbook workbook = WorkbookFormatProvidersManager.Import(extension, input);
        workbook.Name = openFileDialog.SafeFileName; // in the default implementation this is set after applying the document to RadSpreadsheet and triggers the event
       
        this.radSpreadsheet.Workbook = workbook;
    }
}