我需要在选中/取消选中复选框后运行一个命令。复选框通过StackLayout的项目源在页面中呈现，EventToCommandBehavior来自MAUI CommunityToolkit。
当应该呈现页面时（最有可能是在分析和处理XAML时）会引发异常。异常消息如下：“由于对象的当前状态，操作无效。"，这不是很有帮助（我缺少什么状态，谁是所有者，什么是无效的）。
也许打个电话能帮上忙？

at Microsoft.Maui.Controls.Binding.ApplyRelativeSourceBinding(BindableObject targetObject, BindableProperty targetProperty) in D:\a\_work\1\s\src\Controls\src\Core\Binding.cs:line 152
  at System.Threading.Tasks.Task.<>c.<ThrowAsync>b__128_0(Object state)
  at Android.App.SyncContext.<>c__DisplayClass2_0.<Post>b__0() in /Users/runner/work/1/s/xamarin-android/src/Mono.Android/Android.App/SyncContext.cs:line 36
  at Java.Lang.Thread.RunnableImplementor.Run() in /Users/runner/work/1/s/xamarin-android/src/Mono.Android/Java.Lang/Thread.cs:line 36
  at Java.Lang.IRunnableInvoker.n_Run(IntPtr jnienv, IntPtr native__this) in /Users/runner/work/1/s/xamarin-android/src/Mono.Android/obj/Release/net6.0/android-31/mcw/Java.Lang.IRunnable.cs:line 84
  at Android.Runtime.JNINativeWrapper.Wrap_JniMarshal_PP_V(_JniMarshal_PP_V callback, IntPtr jnienv, IntPtr klazz) in /Users/runner/work/1/s/xamarin-android/src/Mono.Android/Android.Runtime/JNINativeWrap

我已经在Xamarin中使用过几次相同的技术。它在那里如预期的那样工作，但是在MAUI中下面的代码抛出InvalidOperationException。内容页面和视图模型被正确地创建（构造函数传递），但是稍后某个地方抛出了异常，老实说不知道为什么。

<StackLayout 
    BindableLayout.ItemsSource="{Binding GameVariants}">
    <BindableLayout.ItemTemplate>
        <DataTemplate x:DataType="bindable:SelectExpansion">
            <StackLayout Orientation="Horizontal" VerticalOptions="Center">
                <CheckBox
                    IsEnabled="{Binding IsExpansion}"
                    IsChecked="{Binding Selected}">
                    <CheckBox.Behaviors>
                        <toolkit:EventToCommandBehavior
                            EventName="CheckedChanged"
                            Command="{Binding Source={RelativeSource AncestorType={x:Type vm:SelectExpansionsPageViewModel}}, Path=SelectExpansionCommand}"
                            CommandParameter="{Binding .}" />
                    </CheckBox.Behaviors>
                </CheckBox>
                <Label Text="{Binding Expansion}" VerticalTextAlignment="Center" />
            </StackLayout>
        </DataTemplate>
    </BindableLayout.ItemTemplate>
</StackLayout>

后面的代码只包含通过依赖项设置上下文。

public partial class SelectExpansionsPage : ContentPage
{
    public SelectExpansionsPage(SelectExpansionsPageViewModel vm)
    {
        BindingContext = vm;
        InitializeComponent();
    }
}

这是页面视图模型

public partial class SelectExpansionsPageViewModel : ObservableObject
{
    public SelectExpansionsPageViewModel(Game state)
    {
        GameVariants = new ObservableCollection<SelectExpansion>(AvailableExpansions.Expansions.Select(item =>
        {
            item.Selected = state.Expansions.Contains(item.Expansion);

            return item;
        }));
    }

    public ObservableCollection<SelectExpansion> GameVariants { get; }
    
    [RelayCommand]
    public void SelectExpansion(SelectExpansion item)
    {
        Debug.WriteLine("Select item changed");
    }
}