ColorPicker Custom Style Designer An Exception was thrown.

[Psyduck]

Hellp

 

In the previous post I asked a question and got an answer..
But there was a problem.

It is related to number 1. ( https://www.telerik.com/forums/is-a-custom-color-picker-possible )

 

It runs fine until the build is successful and I start debugging and finish.

Using <Setter Property = "local : CustomColorPickerOpenBehavior"Value = "True"/> crashes the designer.

Where xaml designer Exception was thrown.

 

InvalidOperationException: Sequence contains no matching element

 

 

Deleting the CustomColorPickerOpenBehavior property shows the xaml designer.

If the property is created again, an exception occurs.

 

What is the problem?

Thanks.

<Style TargetType="telerik:RadColorPicker" BasedOn="{StaticResource RadColorPickerStyle}">
	<Setter Property="Padding" Value="5" />
	<Setter Property="SplitButtonStyle">
		<Setter.Value>
			<Style TargetType="telerik:RadSplitButton" BasedOn="{StaticResource RadSplitButtonStyle}">
				<Setter Property="mat:MaterialAssist.FocusBrush"		Value="Transparent"/>
				<Setter Property="mat:MaterialAssist.MouseOverBrush"	Value="Transparent"/>
				<Setter Property="behaviour:ColorPickerButtonSync.IsEnabled" Value="True" />
				<Setter Property="IsChecked" Value="{Binding IsDropDownOpen, RelativeSource={RelativeSource AncestorType=telerik:RadColorPicker}}" />
			</Style>
		</Setter.Value>
	</Setter>
</Style>

<telerik:RadColorPicker Width="70" SelectedColor="Red" IsRecentColorsActive="True">
	<telerik:RadColorPicker.ContentTemplate>
		<DataTemplate>
			<Rectangle	Width="35" Height="25"
									Fill="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type telerik:RadColorPicker}},
									Path=SelectedColor, Converter={StaticResource mediaToBrushConverter}}" />
		</DataTemplate>
	</telerik:RadColorPicker.ContentTemplate>

	<telerik:RadColorPicker.AdditionalContent>
		<ContentControl HorizontalContentAlignment="Stretch" Content="{Binding}" >
			<ContentControl.ContentTemplate>
				<DataTemplate>
					<Grid>
						<telerik:RadButton	Height="26" BorderThickness="0"
														HorizontalContentAlignment="Left"
														Command="{Binding OnClickOpenEditColorsCommand}"
														CommandParameter="{Binding RelativeSource={RelativeSource Mode=FindAncestor,AncestorType={x:Type telerik:RadColorPicker}}}"
														>
							<telerik:RadButton.Content>
								<TextBlock Text="More Colors..." Margin="26 0 0 0" />
							</telerik:RadButton.Content>
						</telerik:RadButton>
					</Grid>
				</DataTemplate>
			</ContentControl.ContentTemplate>
		</ContentControl>
	</telerik:RadColorPicker.AdditionalContent>
</telerik:RadColorPicker>

 

public class ColorPickerButtonSync
    {
        public static bool GetIsEnabled(DependencyObject obj)
        {
            return (bool)obj.GetValue(IsEnabledProperty);
        }

        public static void SetIsEnabled(DependencyObject obj, bool value)
        {
            obj.SetValue(IsEnabledProperty, value);
        }

        public static readonly DependencyProperty IsEnabledProperty =
            DependencyProperty.RegisterAttached("IsEnabled", typeof(bool), typeof(ColorPickerButtonSync), new PropertyMetadata(false, new PropertyChangedCallback(OnIsEnabledChanged)));

        private static void OnIsEnabledChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            var button = d as RadSplitButton;
            button.IsToggle = true;
            button.Loaded += Button_Loaded;
            button.Checked += SplitButton_Checked;
            button.Unchecked += SplitButton_Unchecked;
            button.DropDownOpened += Button_DropDownOpened;
            button.DropDownClosed += Button_DropDownClosed;
        }

        private static void Button_Loaded(object sender, RoutedEventArgs e)
        {
            var splitButton = sender as RadSplitButton;
            var colorSelector = splitButton.DropDownContent as RadColorSelector;
            colorSelector.Loaded += (s, a) =>
            {
                var rootElement = colorSelector.ChildrenOfType<Grid>().First(x => x.Name == "RootElement");
                Grid.SetRow(rootElement.Children[1], 4);
                Grid.SetRow(rootElement.Children[2], 5);
                Grid.SetRow(rootElement.Children[3], 6);
                Grid.SetRow(rootElement.Children[4], 1);
                Grid.SetRow(rootElement.Children[5], 2);
                Grid.SetRow(rootElement.Children[6], 3);
            };

            var dropDownPart = splitButton.ChildrenOfType<RadToggleButton>().First(x => x.Name == "DropDownPart");
            var rectangle = splitButton.ChildrenOfType<Rectangle>().First(x => x.Name == "Separator");
            //System.InvalidOperationException: 'Sequence contains no matching element'
            dropDownPart.Visibility = Visibility.Collapsed;
            rectangle.Visibility = Visibility.Collapsed;
        }

        private static void Button_DropDownClosed(object sender, RoutedEventArgs e)
        {
            var splitButton = sender as RadSplitButton;
            splitButton.IsChecked = false;
        }

        private static void Button_DropDownOpened(object sender, RoutedEventArgs e)
        {
            var splitButton = sender as RadSplitButton;
            splitButton.IsChecked = true;
        }

        private static void SplitButton_Checked(object sender, RoutedEventArgs e)
        {
            var splitButton = sender as RadSplitButton;
            var colorPicker = splitButton.ParentOfType<RadColorPicker>();
            colorPicker.IsDropDownOpen = true;
        }

        private static void SplitButton_Unchecked(object sender, RoutedEventArgs e)
        {
            var splitButton = sender as RadSplitButton;
            var colorPicker = splitButton.ParentOfType<RadColorPicker>();
            colorPicker.IsDropDownOpen = false;
        }
    }

 

 

[Dilyan Traykov]

Hello,

Thank you for the provided images and code snippets.

I tested this with the sample project I last provided in the forum thread you referenced with the latest version of Visual Studio 2019, however, I do not observe any exceptions, and the RadColorPicker control is displayed as expected at my end. Here's a screenshot of the result I observe after building the project:

What I can suggest is to either try this with the latest version of Visual Studio or add the following if statement to avoid the exception:

        private static void Button_Loaded(object sender, RoutedEventArgs e)
        {
            var splitButton = sender as RadSplitButton;
            if (!System.ComponentModel.DesignerProperties.GetIsInDesignMode(splitButton))
            {
                var dropDownPart = splitButton.ChildrenOfType<RadToggleButton>().First(x => x.Name == "DropDownPart");
                var rectangle = splitButton.ChildrenOfType<Rectangle>().First(x => x.Name == "Separator");
                dropDownPart.Visibility = Visibility.Collapsed;
                rectangle.Visibility = Visibility.Collapsed;
                var colorSelector = splitButton.DropDownContent as RadColorSelector;
                colorSelector.Loaded += (s, a) =>
                {
                    var rootElement = colorSelector.ChildrenOfType<Grid>().First(x => x.Name == "RootElement");
                    Grid.SetRow(rootElement.Children[1], 4);
                    Grid.SetRow(rootElement.Children[2], 5);
                    Grid.SetRow(rootElement.Children[3], 6);
                    Grid.SetRow(rootElement.Children[4], 1);
                    Grid.SetRow(rootElement.Children[5], 2);
                    Grid.SetRow(rootElement.Children[6], 3);
                };
            }
        }

Please let me know if any of these approaches works for you.

Regards,
Dilyan Traykov
Progress Telerik

[Psyduck]

Hello.

 

I am using Visual Studio Community version 16.9.4. This is a post uploaded to the latest version.

Learn the GetIsInDesignMode function. This avoids the designer exception. I will use this.

 

DesignerProperties.GetIsInDesignMode doesn't catch breakpoints even when debugging, so it doesn't affect performance, right?

Is it just the code getting a little dirty?

 

Thanks.

 

[Martin Ivanov]

The line DesignerProperties.GetIsInDesignMode will be also evaluated by the debugger. In other words, it catches breakpoints. However, the effect on the performance won't be noticeable.