Question

Suppose I have a style like

<Style x:Key="NotificationItemTemplate" TargetType="{x:Type ListBoxItem}">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type ListBoxItem}">
                <DockPanel LastChildFill="False">
                    <DockPanel.Background>
                        <LinearGradientBrush>
                            <GradientStop Offset="0" Color="#FF565656" /> <!-- How to change color values -->
                            <GradientStop Offset="1" Color="#FF353535" />
                        </LinearGradientBrush>
                    </DockPanel.Background>
                    ...
                </DockPanel>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

How can I set the color value of a gradient stop as labeled above to a different color, say on MouseOver, I know I use a Trigger, but how do I refer to that color value?

Answer 1

Unfortunately, I’m not sure if you can do it for a single gradient stop. You likely have to trigger to change the entire background brush:

<Style TargetType="{x:Type ListBoxItem}">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type ListBoxItem}">
                <DockPanel LastChildFill="False" x:Name="dock">
                    <DockPanel.Background>
                        <LinearGradientBrush>
                            <GradientStop Offset="0" Color="#FF565656" />
                            <!-- How to change color values -->
                            <GradientStop Offset="1" Color="#FF353535" />
                        </LinearGradientBrush>
                    </DockPanel.Background>
                    <ContentPresenter />
                </DockPanel>
                <ControlTemplate.Triggers>
                    <Trigger Property="IsMouseOver" Value="True">
                        <Setter TargetName="dock" Property="Background">
                            <Setter.Value>
                                <LinearGradientBrush>
                                    <GradientStop Offset="0" Color="#00CDFFFF" />
                                    <!-- How to change color values -->
                                    <GradientStop Offset="1" Color="#FF343465" />
                                </LinearGradientBrush>
                            </Setter.Value>
                        </Setter>
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>