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

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.

When possible implement PDF/A-3, this is the new standard in enterprises for the upcoming years.

Closure reason:  
The following versions of PDF/A Standard are implemented: PDF/A-1 (2005), PDF/A-2 (2011), PDF/A-3 (2013).
The feature is live with our latest Q1 2015 release.

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.

Develop Apple/MAC theme

Provide a way to convert any UIElement visualtree to a PDF

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.

With the Windows 10 Anniversary update native controls like TextBox provide this out of the box.

List numbering should be restarted when copied list is pasted after content that is not in a list.

Steps to reproduce:
1. Create a file with a list, a blank line, some text, and another blank line
2. Copy the list
3. Paste it on the blank line directly after the list
Expected: The items are added to the end of the existing list
Observed: The items are added to the end of the existing list
4. Paste it on the blank line after the text
Expected: The items are added to a new list and start numbering at 1
Observed: The items are added to the existing list and start numbering at 7

Workaround:
private void RadRichTextBox_CommandExecuting(object sender, Telerik.Windows.Documents.RichTextBoxCommands.CommandExecutingEventArgs e)
{
    if (e.Command is PasteCommand)
    {
        DocumentPosition position = new DocumentPosition(this.radRichTextBox.Document);
        position.MoveToPosition(this.radRichTextBox.Document.CaretPosition);
        position.MoveUp();
        Paragraph previousParagraph = position.GetCurrentParagraphBox().AssociatedParagraph;
        if (previousParagraph.IsInList)
        {
            // We shouldn't restart the numbering when the previous paragraph is in a list.
            return;
        }

        RadDocument doc = ClipboardEx.GetDocument().ToDocument();
        Paragraph firstParagraph = doc.EnumerateChildrenOfType<Paragraph>().First();
        if (firstParagraph != null && firstParagraph.IsInList)
        {
            RadDocumentEditor editor = new RadDocumentEditor(doc);
            editor.Document.CaretPosition.MoveToStartOfDocumentElement(firstParagraph);
            editor.RestartListNumbering();
        }

        this.radRichTextBox.InsertFragment(new DocumentFragment(doc));
        e.Cancel = true;
    }
}

I am attempting to use a ReleativeSource in my bindings in two places in a RadGridView:  1) the header of a column, and 2) one of the columns.  I am getting "System.Windows.Data Error: 4 : Cannot find source for binding with reference" in both cases.

I don't think I need to elaborate much, since https://www.telerik.com/forums/can%27t-find-the-right-ancestor-to-bind-to not only describes it perfectly, but also contains sample code from Telerik that, on my machine, fails the same way.

In addition to the fast document generation, the SpreadStreamProcessing can be adapted to import documents significantly faster than SpreadProcessing.

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

Hi,

I have implemented a WPF application that displays various pages.

I have the following code that is executed on one of my pages after a user logs in. This same code is executed when the user returns to the page:

If myUser.IsInRole("Master") Or myUser.IsInRole("Administrator") Then
            myRadGridView.SelectionMode = SelectionMode.Multiple
Else
           myRadGridView.SelectionMode = SelectionMode.Single
End If

After logging in the myRadGridView grid behaves as if it is SelectionMode.Single even though my user is in the role "Master" and the code branch above is executed to set the myRadGridView grid into SelectionMode.Multiple.

That being said, if I leave the page and come back to it, the same code is executed and the myRadGridView grid finally behaves as it should be in SelectionMode.Multiple.

How do I fix get this to work?

Thank you.

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

Affects RadDateTimePicker control of TelerikWPFControls version 2015.1.1

When the user is typing in a specific date and time, the RadDateTimePicker control's text-to-date parsing doesn't accept an uppercase 'A' at the start of what it expects to be the month's name and automatically errors (displays a tooltip showing 'Error') as soon as an 'A' is input. This prevents the user from entering dates and times more specific than the clickable selection for the months of 'April' and 'August'. However, replacing the 'A' with a lowercase 'a' allows the user to proceed with entering more specific dates and times as normal without the 'Error' tooltip showing. 

E.g.: 
1) the user selects 03 April 2018 17:00:00 from the control's clickable selection of date and times;

2) they then try to type more specific minutes and seconds, e.g. 03 April 2018 17:45:23, but this is not accepted by the control and it displays the 'Error' tooltip;

3) workaround - the user changes 'A' of 'April' to a lowercase 'a', as in 'april'. Now the 'Error' tooltip goes away and the user is able to enter and save the more specific date time of 03 april 2018 17:45:23.

This bug only came to light once the control was live in production (released in January) and prevented our users from entering the specific trade date times necessary for regulatory purposes.

Can you tell me if this bug has been fixed in later versions of the control?

Thanks and regards,

Robert Fiteni

check the attach file,the gridview's droplist extend the screen area,
my screen is 2560x1440/175% DPI/14 inch/windows 10

When I scroll around in RadVirtualGrid, I get empty cells in some places.

Details:
- I set InitialRowCount=21 and InitialColumnCount =17.
- The window that contains the VirtualGrid is rather small, so that the horizontal and vertical scrollbars are visible.
- I can always reproduce this issue, if I scroll completely to the right, then completely to the bottom and then half-way to the left.
- I found out that the CellValueNeeded event is never called with the indexes for these cells.
- I'm using version 2017.2.614.45 (NoXaml) of UI for WPF.
- I attached a screenshot showing the empty cells and my example project.

A project with problems in RadTreeListView in the attachment.

Description of the project:

The element RadTreeListView have the name ObjectsTree.  As the ItemsSource of ObjectsTree set the child elements of ObjectsTreeViewModel. ObjectsTreeViewModel contains child elements of type ParentNode. The elements of ParentNode have childrens with type ChildNode. (In the project are used 3 ParentNode elements with 3 childNodes at everyone).

ChildNode elements that have the property ShowNode  equals false should not be displayed. To do this, used the FilterDescriptor. The property IsConnected of ChildNode elements sets the ShowNode property (ShowNode = IsConnected).

The button "Node to offline" is used to reset a property IsConnected to the selected ParentNode element and to all of his children.
The button "All Nodes to online" is used to set a property IsConnected to the all ParentNode elements and to all of their children.
The button "Check Memory Leak" is used update ObjectTree 10000 times.
If you check radiobutton "With Rebind" update using Rebind() command
If you check radiobutton "With clearing filter" update using command sequence : FilterDescriptors.Clear -> FilterDescriptors.Add.

Description of the problem:
1)	When updating the tree using the sequence of commands FilterDescriptors.Clear (); FilterDescriptors.Add (...):
The visual element displays the elements of tree correctly, but there is a memory leak.

2)	When updating with Rebind ():
Memory leaks are not present, but we may see following bug:
Select ParentNode.
Press the "Node to offline" button      -> The child elements are hidden, but a triangle for expanding the list elements is visible.
When you click on this triangle            -> it disappears
Press the button "All Nodes to online" ->the children and the triangle do not appear.