Short version of feature request: 
It would be nice to be able to enforce unique value in a column in an MVVM environment?

Long version of request:
To enforce a unique value in a column I ended up with a custom ValidationAttribute in the data model. Very much like the last example in the old thread 
https://www.telerik.com/forums/force-validation-on-new-record-insert

Direct link to the example provided by Telerik:
https://www.telerik.com/clientsfiles/375715_328546-TestApp-new.zip 

At a first glance, the solution seems to work, but if you edit a value in a cell and the new value is the same as another cell in the same column, BOTH these cells would have an error. Not just the cell you edited. I understand that not all cells can be validated whenever a single cell is edited, but it would nice if there was way to configure the RadGridView to “refresh” validations of all visible cells when a validation error is either set or removed?

I do not know if a solution like this would fit the internal design of the RadGridView, but it might give you some inspiration :-)

Add an attribute to the column definitions in the GridView:
ValidationTransitionMode= Default | ForceValidationOfAllVisibleCellsInColumn | ForceValidationOfAllVisibleCells

Default: 
No change from existing functionality.

ForceValidationOfAllVisibleCellsInColumn: 
Whenever a validation result of a cell changes (from no_error to error OR from error to no_error) all the visible cells in the column will be re-validated. This would do the trick to enforce uniqness in a column with a custom ValidationAttribute.

ForceValidationOfAllVisibleCells: 
Whenever a validation result of a cell changes (from no_error to error OR from error to no_error) all the visible cells of the complete grid will be re-validated. To be used by people with more complex validation algorithms depending on values in other columns as well.


Steps to visualize the current problem.
◦Run the example (https://www.telerik.com/clientsfiles/375715_328546-TestApp-new.zip )
◦When the application is running, reduce the window height (from the bottom) so that the scroll bar is visible and the top visible row shows “last name”=”Rockhead 0” and the bottom visible row shows “Rockhead 4”.
◦Change last name “Smith 3” to “Smith 1”.
◦Now there is a red border around the cell we edited (as expected) but nothing happens to row 2 (First name=Jane1).
◦Scroll to the bottom and back up to the top.
◦Now there is also an error on row 2 (First name = Jane1).
◦Change “Smith 1” back to “Smith 3” (on the row where First name=Jane 3).
◦The error on the cell edited is now removed, BUT the error on row 2 (Jane 1) is still visible even as all values in the Last name column is now unique.

I got some very good support and a suggestion to modify the control template, but it would still be nice to be able to control the validation execution of cells, other than the current cell.

Complete information can be found in the forum thread:
https://www.telerik.com/forums/enforce-unique-content-in-a-column-using-mvvm#4qSllj_EKkecS6ZtctdwAw 

Regards
/Stefan

UI can still accept more inputs  even if item has been selected in SelectionMode="Single"
Please check the screenshot.

SelectionBoxesVisibility property will be introduced with Q1 2019 expected in the middle of January. When set to Hidden/Collapsed, SearchAutoCompleteBox contains the selected item as text only.

The current workaround is to handle the Loaded event like so:

        private void RadMultiColumnComboBox_Loaded(object sender, RoutedEventArgs e)
        {
            this.combo.DropDownWidth = this.combo.DropDownMinWidth;
        }

The fix for this issue will be available with the next LIB (version 2018.3.1224) expected on Monday, December 24.

I would like to do a Backstage design without writing code, the syntax of XAML is confusing and I do not understand it well, besides being slow, the development of software at design time is always much faster.

In the current version of the WPF SDK Sample Browser Application it is really hard to track what's new and what control was updated. Even the version of Sample Browser by itself (2018.3) is not visible.

Maybe you remember the former Sivlerlight Online Demos (I'm not sure if it is still around but I cannot run it anymore because it needs IE11)? There was always an updated or new badge on the controls. So it was obvious what was new and updated.

I think this should be possible in WPF also.

When hovering with the mouse over the control panels there shoud be more information shown like date of the last update of the sample.

When clicking on a control on viewing the samples of the control, I can only open the folder, open in VS or run it. Sometimes it makes sense to open directly the sample on github to quickly check the version history.

.Net Core 3.0 (https://github.com/dotnet/core/blob/master/roadmap.md) is now activly developed. It will support WPF on Windows. How are your plans to support it?

Any roadmap?

I think that deploying scenario for applications and protecting dll-s are complicated. I think that better way is to use control panel. I want to send you needed informations through control panel, a and I want to provide me my version of dll-s that are protected and I can use it in my app. You build it on your own. The way you are doing it now is complicated, and can produce issues.

     if the pie chart area's size is auto,when adjust the area's  vertical size,the pie's radius  will change in order to fit the label display,it is ok,but when adjust the area's horizontal size,the pie's radius don't  change,looking the attachment file,the label move above the pie.

Currently the palette of a theme can only be set for the entire application. Setting the palette per control instance should also be possible.

The copyright notice is shown on top of the content. It cannot be moved and there is no way for the customer to see the content beneath the notice.

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This item has been moved to the Document Processing portal. It can be found here: https://feedback.telerik.com/Project/184/Feedback/Details/251942-spreadstreamprocessing-implement-workbook-import

Fix available in R2 2018 SP1 version.

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Setting the TextWrapping to Wrap or WrapWithOverflow will not allow the WatermarkContent to be wrapped.

Reason for decline: 

Instead of setting the content inline, we recommend setting it as follows: 

<telerik:RadWatermarkTextBox Width="100">
	<telerik:RadWatermarkTextBox.WatermarkContent>
		<TextBlock TextWrapping="Wrap" Text="Watermark Content Watermark Content Watermark Content Watermark Content" />
	</telerik:RadWatermarkTextBox.WatermarkContent>
</telerik:RadWatermarkTextBox>

More information can be found in our help about using the WatermarkContent and WatermarkTemplate properties: https://docs.telerik.com/devtools/wpf/controls/radwatermarktextbox/features#using-the-watermarkcontent-property
Please let us know if this is not applicable in the scenario of your application.

When both horizontal and vertical ScrollBars are visible in Fluent theme, the "BottomHandle" RepeatButton cannot be pressed as it is overlapped by the horizontal ScrollBar on MouseOver. 

Default behavior will be changed and the scrollbars will be reordered in the ScrollViewer ControlTemplate so on MouseOver the current ScrollBar will have higher Canvas.ZIndex. 

look the attach file.

Hello,

I am using DateTimePicker with JAWS.  Here are the issue I ran into:
1. JAWS reads out watermark 3 times
2. JAWS reads out date and time where there is only date populate and dateformat is set for shortdate.  For example, date is "04/12/2018".  JAWS reads "04/12/2018 00:00:00"
3. Once the date is populated and date field got focus, it will read out date and time at least 2 times.

I work on project that required it to compliance with government section 508. This issue will not allow me to use Telerik's datepicker.  Please fix this.