当radtreeview打开或关闭时，如何更改扩展器按钮

Question

我有两个图标，分别是a和b；我需要我的radtreeviewitem在打开时显示带有图标a的扩展器按钮，在关闭时显示图标b。下面是两个图标

<Style x:Key="ExpanderStyleOpen" TargetType="ToggleButton">
            <Setter Property="IsEnabled" Value="True" />
            <Setter Property="IsTabStop" Value="False" />
            <Setter Property="ToggleButton.IsChecked" Value="True" />
            <Setter Property="Cursor" Value="Hand" />
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="ToggleButton">
                        ...
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
        <Style x:Key="ExpanderStyleClose" TargetType="ToggleButton">
            <Setter Property="IsEnabled" Value="True" />
            <Setter Property="IsTabStop" Value="False" />
            <Setter Property="ToggleButton.IsChecked" Value="False" />
            <Setter Property="Cursor" Value="Hand" />
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="ToggleButton">
                       ...
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>

然后我的radtreeview。。。

<telerik:RadTreeView Name="radTreeView"
<!--static can't change...:(-->
                             ExpanderStyle="{StaticResource ExpanderStyleClose}"
                             FontSize="12"
                             IsLineEnabled="True"
                             IsRootLinesEnabled="False"
                             Visibility="{Binding IsVisible}">

Answer 1

通过使用Trigger，您可以将两种样式组合为一种。

想法是：

1. 将闭合图像设置为样式的实际图像
2. 创建一个Trigger以更改ToggleButton的IsChecked属性。"关闭"时为false，打开时为true

像这样的东西应该起作用：

<Style x:Key="ExpanderStyle" TargetType="{x:Type ToggleButton}">
    <Setter Property="IsEnabled" Value="True" />
    <Setter Property="IsTabStop" Value="False" />
    <Setter Property="Cursor" Value="Hand" />
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type ToggleButton}">
                <StackPanel Orientation="Horizontal">
                    <Grid SnapsToDevicePixels="False" Background="Transparent">
                        <Image x:Name="expanderImage" Source="..." />
                    </Grid>
                    <ContentPresenter />
                </StackPanel>
                <ControlTemplate.Triggers>
                    <Trigger Property="IsChecked" Value="false">
                        <Setter Property="Source" TargetName="expanderImage" Value="..." />
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>