wpf中如何改变Listbox选中项的颜色

你可以使用ListBox的ItemContainerStyle来定义ListBoxItem的样式，然后在样式中设置选中项的背景颜色。以下是一个示例：

<ListBox>
    <ListBox.ItemContainerStyle>
        <Style TargetType="{x:Type ListBoxItem}">
            <Setter Property="Background" Value="Transparent" />
            <Setter Property="BorderBrush" Value="Transparent" />
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type ListBoxItem}">
                        <Border x:Name="Bd"
                                Background="{TemplateBinding Background}"
                                BorderBrush="{TemplateBinding BorderBrush}"
                                BorderThickness="{TemplateBinding BorderThickness}"
                                Padding="{TemplateBinding Padding}">
                            <ContentPresenter />
                        </Border>
                        <ControlTemplate.Triggers>
                            <Trigger Property="IsSelected" Value="True">
                                <Setter TargetName="Bd" Property="Background" Value="#FF007ACC" />
                                <Setter Property="Foreground" Value="White" />
                            </Trigger>
                            <MultiTrigger>
                                <MultiTrigger.Conditions>
                                    <Condition Property="IsSelected" Value="True" />
                                    <Condition Property="Selector.IsSelectionActive" Value="False" />
                                </MultiTrigger.Conditions>
                                <Setter TargetName="Bd" Property="Background" Value="LightGray"/>
                                <Setter Property="Foreground" Value="Black" />
                            </MultiTrigger>
                        </ControlTemplate.Triggers>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
    </ListBox.ItemContainerStyle>
    <ListBoxItem>Item 1</ListBoxItem>
    <ListBoxItem>Item 2</ListBoxItem>
    <ListBoxItem>Item 3</ListBoxItem>
</ListBox>

在这个示例中，选中项的背景颜色被设置为#FF007ACC，未选中项的背景颜色被设置为透明。你可以根据自己的需求进行调整。