with windows10/2k DPI/14 inch screen ,when show the gridview gridline,the line is different.
     the other things,when the tabitem is selected,the dropdownmenu can't mark the selected item.
   look the attach files!

Basing on the "{StaticResource FilterControlStyle}" would cause an InvalidArgumentException, if the types would mismatch. 
If you are to base on a custom style on the default style of either of those controls, you can do it by type reference - e.g. BasedOn="{StaticResource {x:Type telerik:FilteringControl}}"

I want to have opportunity to disable RadExpander header because I want to programmatically expand or collapse RadExpander control.

You have, for example rectangle which is in ContentControl in XAML, next to FluidC.C.

FluidContentControl is in small state. Ona  button click SmallContent is assigned to the Rectangle.

This leads to the exception stated that rectangle is already a logical child of another element.

User can set AutoCalculateBounds to True by the following way:

 public class CustomClusterGenerator : DefaultClusterGenerator
    {
        public override ClusterData CreateCluster(Location center, object item)
        {
            var clusterData = base.CreateCluster(center, item);
            clusterData.AutoCalculateBounds = true;
            return clusterData;
        }
    }

  this.VisualizationLayer1.ClusterGenerator = new CustomClusterGenerator();

When clustering 4 points:

ObservableCollection<DataItem> items = new ObservableCollection<DataItem>()
            {
                new DataItem() {MapLocation = new Telerik.Windows.Controls.Map.Location(20, 30) },
                new DataItem() {MapLocation = new Telerik.Windows.Controls.Map.Location(20, 34) },

                new DataItem() {MapLocation = new Telerik.Windows.Controls.Map.Location(22, 32) },
                new DataItem() {MapLocation = new Telerik.Windows.Controls.Map.Location(18, 32) },
            };

            this.VisualizationLayer1.ItemsSource = items;

EXPECTED:  ClusterData's Bounds must  be:

WEST: 30 and EAST: 34.

Actual Values are 30 and 30 (29.9999 and 30).

looking the attach file,when resize the second gridview's column moving back and forth when at first run the sample,the after columns flicker and the width grow and lessen.and when resize the third column,the 'unit price' column will become the min width.
but when test the microsoft's datagrid,it is good,the any other column width's change is gentle.

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.

look the attach file.

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. 

Fix available in R2 2018 SP1 version.

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.

     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.

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.

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

Telerik.Windows.Controls.SpreadsheetUI.for.Wpf NuGet package is not uploaded on the Telerik NuGet server.

Fix available in LIB Version 2018.3.1029.

I'm using the fluent theme in my app. When I load ColorVariation.Dark, everything is dark except a sub-window. This is a window created by my main window. Its main control is TabControl with most of the tabs items being ListBoxes using data templates. The Listboxes display dark but the window itself is light along with the first tab item which is just a grid with TextBoxes. I don't specify background color on any of these controls so I assumed they would come from the theme. Do I have to do something to pass the info th a sub-window?

An exception is thrown when the ItemsSource of the ItemsSourceProvider is bound to a DataTable and an item is select in the drop-down.

The fix for this issue will be available with our next official version – R1 2019 expected in the middle of January.