插入“Label.Text”的 VisualState.Setters 属性时页面崩溃

Question

我有一个带有标签和开关的 .NET MAUI xaml 页面。当我尝试使用VisualState-setters 更改打开/关闭时的标签文本值时，它可以与模拟器和手机调试器模式一起使用，但是当我将其下载到我的 Android 手机中时，尝试打开时页面崩溃！这是重现问题的代码部分：

    <HorizontalStackLayout Grid.Row="2" Grid.Column="0" Margin="5" Spacing="7" BackgroundColor="White" HeightRequest="50">
                                
                <!-- Automatic-Manual -->
                <VerticalStackLayout Margin="2" >
                    <Label x:Name="LblAutoMan" Text="Automatic" VerticalOptions="Start" HorizontalOptions="Center" HeightRequest="20" WidthRequest="65"/>
                    <Switch IsToggled="True" HorizontalOptions="Start" VerticalOptions="Center" HeightRequest="10">
                        <VisualStateManager.VisualStateGroups>
                            <VisualStateGroup Name="CommonStates">
                                <VisualState Name="On">
                                    <VisualState.Setters>
                                        <Setter Property="ThumbColor" Value="Green" />
                                        <Setter TargetName="LblAutoMan" Property="Label.Text" Value="Automatic" /> 
                                    </VisualState.Setters>
                                </VisualState>
                                <VisualState Name="Off">
                                    <VisualState.Setters>
                                        <Setter Property="ThumbColor" Value="Red" />
                                        <Setter TargetName="LblAutoMan" Property="Label.Text" Value="Manual" /> 
                                    </VisualState.Setters>
                                </VisualState>
                            </VisualStateGroup>
                        </VisualStateManager.VisualStateGroups>
                    </Switch>
                </VerticalStackLayout>
               
            </HorizontalStackLayout>

如果我评论两行：<Setter TargetName="LblAutoMan"

有人可以解决这个错误吗？

Answer 1

根据这个问题，你需要将你的<VisualStateGroup>内部<VisualStateGroupList>标签括起来：

<HorizontalStackLayout Grid.Row="2" Grid.Column="0" Margin="5" Spacing="7" BackgroundColor="White" HeightRequest="50">
                            
    <!-- Automatic-Manual -->
    <VerticalStackLayout Margin="2" >
        <Label x:Name="LblAutoMan" Text="Automatic" VerticalOptions="Start" HorizontalOptions="Center" HeightRequest="20" WidthRequest="65"/>
        <Switch IsToggled="True" HorizontalOptions="Start" VerticalOptions="Center" HeightRequest="10">
            <VisualStateManager.VisualStateGroups>
                <VisualStateGroupList>
                    <VisualStateGroup Name="CommonStates">
                        <VisualState Name="On">
                            <VisualState.Setters>
                                <Setter Property="ThumbColor" Value="Green" />
                                <Setter TargetName="LblAutoMan" Property="Label.Text" Value="Automatic" /> 
                            </VisualState.Setters>
                        </VisualState>

                        <VisualState Name="Off">
                            <VisualState.Setters>
                                <Setter Property="ThumbColor" Value="Red" />
                                <Setter TargetName="LblAutoMan" Property="Label.Text" Value="Manual" /> 
                            </VisualState.Setters>
                        </VisualState>
                    </VisualStateGroup>
                  </VisualStateGroupList>
                </VisualStateManager.VisualStateGroups>
        </Switch>
    </VerticalStackLayout>
</HorizontalStackLayout>