ToggleButton：样式不适用于 IsChecked 绑定

Question

我有一个这样定义的 ToggleButton：

<ToggleButton x:Name="tbtn_delivery_advice" IsChecked="{Binding ServiceOptions.Advice.Requested}" Style="{DynamicResource ToggleButtonStyle}" Grid.Column="0" Grid.Row="1" Width="28" Margin="2 7" VerticalAlignment="Top"/>

还有我在网上找到的这种风格：

        <Style x:Key="ToggleButtonStyle" TargetType="{x:Type ToggleButton}">
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type ToggleButton}">
                        <Viewbox>
                            <Border x:Name="Border" CornerRadius="10"
                            Background="#FFFFFFFF"
                            Width="40" Height="20"
                            BorderBrush="#FF707070"
                            BorderThickness="1">
                                <Ellipse x:Name="Ellipse" Fill="#FFFFFFFF" Stretch="Uniform"
                                 Margin="2 1 2 1"
                                 Stroke="LightGray" StrokeThickness="1"
                                 HorizontalAlignment="Stretch">
                                </Ellipse>
                            </Border>
                        </Viewbox>
                        <ControlTemplate.Triggers>
                            <EventTrigger RoutedEvent="Checked">
                                <BeginStoryboard>
                                    <Storyboard>
                                        <ColorAnimation Storyboard.TargetName="Border"
                                                    Storyboard.TargetProperty="(Border.Background).(SolidColorBrush.Color)"
                                                    To="#FF4CD661"
                                                    Duration="0:0:0.1" />
                                        <ThicknessAnimation Storyboard.TargetName="Ellipse"
                                                        Storyboard.TargetProperty="Margin"
                                                        To="20 1 2 1"
                                                        Duration="0:0:0.1" />
                                    </Storyboard>
                                </BeginStoryboard>
                            </EventTrigger>
                            <EventTrigger RoutedEvent="Unchecked">
                                <BeginStoryboard>
                                    <Storyboard>
                                        <ColorAnimation Storyboard.TargetName="Border"
                                                    Storyboard.TargetProperty="(Border.Background).(SolidColorBrush.Color)"
                                                    To="White"
                                                    Duration="0:0:0.1" />
                                        <ThicknessAnimation Storyboard.TargetName="Ellipse"
                                                        Storyboard.TargetProperty="Margin"
                                                        To="2 1 2 1"
                                                        Duration="0:0:0.1" />
                                    </Storyboard>
                                </BeginStoryboard>
                            </EventTrigger>
                        </ControlTemplate.Triggers>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>

当 IsChecked 未绑定到任何东西或初始值为false的属性时，Button 工作得很好并且看起来像预期的那样。 但是一旦初始值为true ，我就会得到一个异常。 该消息指出在System.Windows.Controls.ControlTemplate中找不到名称Border 。

我不知道如何解决这个问题，并希望得到任何帮助。

Answer 1

我找到了一个解决方案，即使我仍然不能百分百确定问题是什么。

我认为可能是在按钮完全初始化之前调用了Checked事件触发器。 所以我只是从EventTrigger切换到Trigger ，现在一切正常。

这是我的工作方式：

        <Style x:Key="ToggleButtonStyle" TargetType="{x:Type ToggleButton}">
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type ToggleButton}">
                        <Viewbox>
                            <Border x:Name="Border" CornerRadius="10"
                            Background="#FFFFFFFF"
                            Width="40" Height="20"
                            BorderBrush="#FF707070"
                            BorderThickness="1">
                                <Ellipse x:Name="Ellipse" Fill="#FFFFFFFF" Stretch="Uniform"
                                 Margin="2 1 2 1"
                                 Stroke="LightGray" StrokeThickness="1"
                                 HorizontalAlignment="Stretch">
                                </Ellipse>
                            </Border>
                        </Viewbox>
                        <ControlTemplate.Triggers>
                            <Trigger Property="ToggleButton.IsChecked" Value="True">
                                <Trigger.EnterActions>
                                    <BeginStoryboard>
                                        <Storyboard>
                                            <ColorAnimation Storyboard.TargetName="Border"
                                                    Storyboard.TargetProperty="(Border.Background).(SolidColorBrush.Color)"
                                                    To="#FF4CD661"
                                                    Duration="0:0:0.1" />
                                            <ThicknessAnimation Storyboard.TargetName="Ellipse"
                                                        Storyboard.TargetProperty="Margin"
                                                        To="20 1 2 1"
                                                        Duration="0:0:0.1" />
                                        </Storyboard>
                                    </BeginStoryboard>
                                </Trigger.EnterActions>
                                <Trigger.ExitActions>
                                    <BeginStoryboard>
                                        <Storyboard>
                                            <ColorAnimation Storyboard.TargetName="Border"
                                                    Storyboard.TargetProperty="(Border.Background).(SolidColorBrush.Color)"
                                                    To="White"
                                                    Duration="0:0:0.1" />
                                            <ThicknessAnimation Storyboard.TargetName="Ellipse"
                                                        Storyboard.TargetProperty="Margin"
                                                        To="2 1 2 1"
                                                        Duration="0:0:0.1" />
                                        </Storyboard>
                                    </BeginStoryboard>
                                </Trigger.ExitActions>
                            </Trigger>
                        </ControlTemplate.Triggers>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>