Change the color displayed in the WPF Charting Toolkit Legend

Question

I have the following style that deletes a data point and randomly generates line color for line graphs of lines

<Style x:Key="LineDataPointStyle" 
        TargetType="ChartingToolkit:LineDataPoint">
    <Setter Property="Foreground" Value="DarkGreen"/>
    <Setter Property="IsTabStop" Value="False"/>
    <Setter Property="Width" Value="NaN"/>
    <Setter Property="Height" Value="NaN"/>
    <Setter Property="Background" 
            Value="{Binding RelativeSource={RelativeSource Self}, 
                            Converter={StaticResource ColorBrushConverter}}"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="ChartingToolkit:LineDataPoint">
                <Grid x:Name="Root" Opacity="0"/>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

where is the converter:

public class ColorToBrushConverter : IValueConverter
{
    public object Convert(object value, Type targetType, 
        object parameter, System.Globalization.CultureInfo culture)
    {
        return new SolidColorBrush(Utils.GenerateRandomColor());
    }

    public object ConvertBack(object value, Type targetType, 
        object parameter, System.Globalization.CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

This generates a string in random color, but the legend is different in color; it is either automatically generated by the library itself, or it also calls my converter through a style template.

How can I make a legend print the correct color?

Answer 1

Note: the answer to the question Killercamthat was asked here . The answer to this question is especially suitable for his generosity, so at his request I publish it here.

Button .

Part I. Binding in ControlTemplate

Binding ControlTemplate, :

<ControlTemplate TargetType="{x:Type SomeControl}">
    <Rectangle Fill="{TemplateBinding Background}" />

MSDN:

A TemplateBinding - , , {Binding RelativeSource={RelativeSource TemplatedParent}}.

Notes about using TemplateBinding

TemplateBinding VisualTree, TemplateBinding . , TemplateBinding , Freezable ( ), - VisualBrush. Binding :

<FreezableControl Property="{Binding RelativeSource={RelativeSource TemplatedParent},
                                     Path=Background}" />

, TemplateBinding:

<Rectangle Fill="{Binding RelativeSource={RelativeSource TemplatedParent},
                          Path=Background}" />

:

<Rectangle Fill="{Binding Background, 
                          RelativeSource={RelativeSource AncestorType={x:Type SomeControl}}, 
                          Path=Background}" />

Part II. Notes about your version

ControlTemplate, Binding background Border. Border , Tag .

Example of using

ChartingToolkit , Button, .

Solution 1: using Tag

<Window.Resources>
    <Style x:Key="TestButtonStyle" TargetType="{x:Type Button}">
        <Setter Property="BorderThickness" Value="0" />
        <Setter Property="IsTabStop" Value="False" />

        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type Button}">
                    <!-- Here we are set Tag for Border Background -->
                    <Border Background="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=Tag}" 
                            BorderThickness="{TemplateBinding BorderThickness}">

                        <Grid>
                            <Rectangle Width="24" 
                                       Height="24" 
                                       Fill="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=Background}" 
                                       Stroke="{TemplateBinding BorderBrush}" />

                            <ContentPresenter Content="{TemplateBinding Content}" 
                                              HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                                              VerticalAlignment="{TemplateBinding VerticalContentAlignment}" />
                        </Grid>
                    </Border>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</Window.Resources>

<Grid>
    <Button Name="TestButton"
            Style="{StaticResource TestButtonStyle}"
            Content="Test"
            HorizontalContentAlignment="Center"
            VerticalContentAlignment="Center"
            Tag="Green"
            Background="Aquamarine"
            Width="100"
            Height="100" />
</Grid>

Output

Rectangle : Rectangle, Border. , :

• Border and Rectangle , : Background, BorderThickness, BorderBrush .., Tag .

• , "Tag" .

, , .

ButtonExt.cs

public static class ButtonExt
{
    #region RectangleBackground Property

    public static readonly DependencyProperty RectangleBackgroundProperty;

    public static void SetRectangleBackground(DependencyObject DepObject, Brush value)
    {
        DepObject.SetValue(RectangleBackgroundProperty, value);
    }

    public static Brush GetRectangleBackground(DependencyObject DepObject)
    {
        return (Brush)DepObject.GetValue(RectangleBackgroundProperty);
    }

    #endregion

    #region RectangleBorderBrush Property

    public static readonly DependencyProperty RectangleBorderBrushProperty;

    public static void SetRectangleBorderBrush(DependencyObject DepObject, Brush value)
    {
        DepObject.SetValue(RectangleBorderBrushProperty, value);
    }

    public static Brush GetRectangleBorderBrush(DependencyObject DepObject)
    {
        return (Brush)DepObject.GetValue(RectangleBorderBrushProperty);
    }

    #endregion       

    #region Button Constructor

    static ButtonExt()
    {
        #region RectangleBackground

        PropertyMetadata BrushPropertyMetadata = new PropertyMetadata(Brushes.Transparent);

        RectangleBackgroundProperty = DependencyProperty.RegisterAttached("RectangleBackground",
                                                            typeof(Brush),
                                                            typeof(ButtonExt),
                                                            BrushPropertyMetadata);

        #endregion

        #region RectangleBorderBrush

        RectangleBorderBrushProperty = DependencyProperty.RegisterAttached("RectangleBorderBrush",
                                                            typeof(Brush),
                                                            typeof(ButtonExt),
                                                            BrushPropertyMetadata);

        #endregion
    }

    #endregion
}

MainWindow.xaml

<Window.Resources>
    <Style x:Key="TestButtonExtensionStyle" TargetType="{x:Type Button}">
        <Setter Property="Width" Value="80" />
        <Setter Property="Height" Value="80" />
        <Setter Property="Background" Value="Green" />
        <Setter Property="BorderBrush" Value="Pink" />
        <Setter Property="BorderThickness" Value="4" />

        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type Button}">
                    <Border Background="{TemplateBinding Background}" 
                            BorderBrush="{TemplateBinding BorderBrush}"
                            BorderThickness="{TemplateBinding BorderThickness}">

                        <Grid>
                            <Rectangle Fill="{TemplateBinding PropertiesExtension:ButtonExt.RectangleBackground}" 
                                       Stroke="{TemplateBinding PropertiesExtension:ButtonExt.RectangleBorderBrush}"
                                       Width="30" 
                                       Height="30" />

                            <ContentPresenter Content="{TemplateBinding Content}" 
                                              HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                                              VerticalAlignment="{TemplateBinding VerticalContentAlignment}" />
                        </Grid>
                    </Border>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</Window.Resources>

<Grid>
    <Button Style="{StaticResource TestButtonExtensionStyle}"
            PropertiesExtension:ButtonExt.RectangleBackground="Aquamarine"
            PropertiesExtension:ButtonExt.RectangleBorderBrush="Black"
            Content="Test" />
</Grid>

Output

Part III. Setting values for dependency properties

, Set Get :

public static void SetRectangleBackground(DependencyObject DepObject, Brush value)
{
    DepObject.SetValue(RectangleBackgroundProperty, value);
}

public static Brush GetRectangleBackground(DependencyObject DepObject)
{
    return (Brush)DepObject.GetValue(RectangleBackgroundProperty);
}

:

Set

ButtonExt.SetRectangleBackground(MyButton, Brushes.Red);

Get

Brush MyBrush = ButtonExt.GetRectangleBackground(MyButton);

. . , Button. Mode=TwoWay, UpdateSourceTrigger=PropertyChanged Binding GetBindingExpression().UpdateTarget(), .

, , . , , , , , , , .

Model ViewModel .

:

<Button Style="{StaticResource TestButtonExtensionStyle}"
        adp:ButtonExt.RectangleBackground="{Binding Path=Model.RectBackground,
                                                    Mode=TwoWay, 
                                                    UpdateSourceTrigger=PropertyChanged}"
        adp:ButtonExt.RectangleBorderBrush="{Binding Path=Model.RectBorderBrush,
                                                     Mode=TwoWay, 
                                                     UpdateSourceTrigger=PropertyChanged}" />

RectBackground RectBorderBrush INotifyPropertyChanged.

DataTemplate . DataTemplate MVVM, .

, DataTemplate, :

()

One ViewModel UserControl Window ViewModels

Answer 2

- , , ( , ). , , , .

- :

//If you declare your style in a resource dictionary, get that resource first

ResourceDictionary resD = (ResourceDictionary)Application.LoadComponent(new Uri("ResourcesPlot\\ResourceDictionaryPlot.xaml", UriKind.Relative));

//The actual style


Style lineDataPointStyle= (Style)resD["LineDataPointStyle"];

//Set the color
lineDataPointStyle.Setters.Add(new Setter(BackgroundProperty, Utils.GenerateRandomColor()));

, .

Edit:

( / )

<Style x:Key="CustomLegendItemStyle" TargetType="{x:Type chartingToolkit:LegendItem}">
        <Setter Property="IsTabStop" Value="False" />
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="chartingToolkit:LegendItem">
                    <StackPanel Orientation="Horizontal">
                        <CheckBox VerticalAlignment="Center" Margin="3" IsChecked="true" Checked="DisplaySeries_Checked" Unchecked="DisplaySeries_Unchecked"/>
                        <!--<Rectangle VerticalAlignment="Center" Width="8" Height="8" Fill="{DynamicResource MyBackgroundDiode1}" Stroke="{Binding BorderBrush}" StrokeThickness="1" Margin="5,5,5,5" />-->
                        <chartingToolkit:LegendItem VerticalAlignment="Center" Content="{TemplateBinding Content}" />

                    </StackPanel>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>