Questions on UI for WPF Forum

1 answer

364 views

I am using QueryableCollectionView (QCV) together with EF Core 3.1.2 as a datasource for RadGridView. As soon as I set an AggregateFunctions on a DataColumn in my grid EF Core throws an error:

System.InvalidOperationException
HResult=0x80131509
Message= Processing of the LINQ expression '(GroupByShaperExpression:
KeySelector: (1),
ElementSelector:(EntityShaperExpression:
EntityType: SalesOrderHeader
ValueBufferExpression:
(ProjectionBindingExpression: EmptyProjectionMember)
IsNullable: False
)
)' by 'RelationalProjectionBindingExpressionVisitor' failed. This may indicate either a bug or a limitation in EF Core. See https://go.microsoft.com/fwlink/?linkid=2101433 for more detailed information.
Source= Microsoft.EntityFrameworkCore.Relational

I consider this as a serious bug. The way EF Core 3.x supports query evaluation has changed drastically compared to former versions (as mentioned in the link inside the error message) and it seems that Telerik's query building is not taken this fact into account.

It is quite simple to reproduce the error:

1. Create a .NET Core 3 WPF project with Telerik.UI.for.Wpf.NetCore 2020.1.218
2. Add EF Core 3.1.x package
3. Create a DbContext with just one table (which is enough to reproduce the error)
4. Create a QCV from the table
5. Place a RadGridView and bind it to the QCV

Everything should work as expected. Now place an AggregateFunction like CountFunction on one DataColumn and you should see the error. There is also a similar issue in this thread:

https://www.telerik.com/forums/todatasource-throws-exception-using-ef-core-3-0-with-groups

At the moment I am migrating a WPF application from .NET 4.6.1 to .NET Core 3 and I rely heavily on QCV. I would be very grateful for any help!

Regards
Heiko

General Discussions

answered on 16 Mar 2020

3 answers

172 views

Intervals not showing

Fairly new, and I hope this isn't a dumb question, but...

When I create a RadTimeBar by its lonesome, and bind values to the PeriodStart/End, SelectionStart/End everything works as expected. If I use it in a ItemTemplate in a RadListBox, intervals no longer show.

Any ideas?

TimeBar

answered on 16 Mar 2020

2 answers

276 views

Change foreground color of merged cell

Hi,

I am trying to conditionally format the contents of merged cells. For this I have implemented a MergedCellStyleSelector as per the examples. The setters all work as expected except for setting the foreground color. If I look at the live visual tree in VS I can see that the data gets presented in a text block which does not inherit from the foreground property set on the conditional style.

public class MergedSlotStyleSelector : StyleSelector

{

public override Style SelectStyle(object item, DependencyObject container)

{

var info = item as MergedCellInfo;

var cell = container as GridViewMergedCell;

var column = cell.DataColumn;

var ctx = cell.DataContext as MainViewModel;

var vm = ctx.SectionElements.OrderBy(o=>o.Sequence).ToArray()[info.VerticalStart];

var baseStyle = Application.Current.Resources["GridViewMergedCellStyle"] as Style;

var background = new SolidColorBrush(Telerik.Windows.Controls.FluentPalette.Palette.AccentColor);

var foreground = new SolidColorBrush(Telerik.Windows.Controls.FluentPalette.Palette.PrimaryMouseOverColor);

var style = new Style(typeof(GridViewMergedCell), baseStyle);

style.Setters.Add(new Setter(GridViewMergedCell.VerticalContentAlignmentProperty, VerticalAlignment.Center));

style.Setters.Add(new Setter(GridViewMergedCell.HorizontalContentAlignmentProperty, HorizontalAlignment.Right));

if (vm.IsRulingSegment)

{

style.Setters.Add(new Setter(GridViewMergedCell.BackgroundProperty, background)); //<-- THIS WORKS

style.Setters.Add(new Setter(GridViewMergedCell.ForegroundProperty, foreground)); //<-- THIS DOES NOT WORK

style.Setters.Add(new Setter(GridViewMergedCell.FontWeightProperty, FontWeights.Bold)); //<-- THIS WORKS

}

return style;

}

GridView

answered on 16 Mar 2020

1 answer

114 views

Find Row number and set it to binded item property

Hi Telerik team,

I have a special case where it is required to find a row number automatically and later on save it to respective binded property.

I have gone through some of examples to find row indexes but can you please guide me how to set them to respective fields.

GridView

answered on 13 Mar 2020

1 answer

281 views

Hooking into ValueChange

I am trying to validate a Textbox that will hold an IP Address. I have a working example that works as expected

<telerik:RadMaskedTextInput ValidationRegex="{x:Static maskedInput:ValidationHelper.IP}" x:Name="hueIpAddress" Height="23" Margin="203,39,0,0" VerticalAlignment="Top" Width="120" HorizontalAlignment="Left"
EmptyContent="Enter IP Address"
InputBehavior="Insert"
Mask="{Binding Path=Text, ElementName=Mask, Mode=TwoWay}"
IsClearButtonVisible="False"
SelectionOnFocus="CaretToEnd"
TextMode="PlainText"
UpdateValueEvent="ProperyChanged" />

But no matter what I do, I cannot get an event to fire when the value is updated. I have tried ValueChanged and ValueChanging, but none fire as expected, and I am not interested in playing the PreviewTextInput/KeyDown game which is unreliable. I want to be able to update a label on my page with the current value of the text box, and doing it via the handle method as I will need to do other stuff as well.

MaskedInput (Numeric, DateTime, Text, Currency)

answered on 12 Mar 2020

2 answers

242 views

Removing the dropdown

I need the time interval to be 1 minute. This makes the dropdown unusable. How can I disable or just remove the dropdown completely so it works like the old WinForms time picker? I saw this:

https://www.telerik.com/forums/how-to-remove-the-drop-down-button

but it's pretty old and I don't really want to mess with Expression Blend (if it even still exists?). I would also need the cursor keys and mouse wheel to increment/decrement the current value.

Or is it better to just try make the NumericUpDown work like a TimePicker?

TimePicker

answered on 11 Mar 2020

5 answers

162 views

With the Office2013 style, the row error display is not correct on the first line

Hello,

As you can see in the attached screenshot, the first row has not a top red line.

GridView

answered on 11 Mar 2020

3 answers

135 views

Communication between RadRichTextBoxRibbonUI and System.Windows.Control.RichTextBox

Created the visual studio project with
telerik:RadRichTextBoxRibbonUI and System.Windows.Controls.RichtextBox

How can we communicate between above two components.

RichTextBox

answered on 11 Mar 2020

1 answer

119 views

Cursor jumps while composing in Telugu

Created one Visual studio project with telerik Richtextbox
Trying to compose in Telugu language using IME keyboard but the cursor is jumping ahead.

The following problem is solved for Devanagari script.

Please go thru the following link for your reference,
https://www.telerik.com/forums/silverlight-richtextbox-unicode-issue

RichTextBox

answered on 11 Mar 2020

1 answer

179 views

Tag with Icon

So I have the honor to write the first post on this board. :-)

I like the new TaskBoard component. What I would like to do is show the tags together with an icon and I can't find a solution for that. Also I can't find a way to define the colour of the tags. Is there a template that I can modify? Any hint would be nice!

Regards
Heiko

TaskBoard

answered on 10 Mar 2020