MVVM新手在这里。当我尝试在MVVM中绑定数组ChoiceText[]时，初始值显示在我的视图中，但更新后的值不显示。

public partial class MainViewModel : ObservableObject
{
    private int _questionNumber = 0;
    private int _numberOfQuestions = 30;
    MainPage.quizQuestion _question = new MainPage.quizQuestion();

    [ObservableProperty]
    string _answerText = "no answer yet...";

    [ObservableProperty]
    string _questionText = "what's this a picture of?";

    [ObservableProperty]
    string _imagePath = "pic1_72dpi.jpg";

    [ObservableProperty]
    string[] _choiceText = {"1", "2", "3", "4"};

    private void LoadQuestion()
    {
        _question = LoadHardCodedQuestion(_questionNumber);
        QuestionText = _question.QText;
        AnswerText = string.Empty;
        ImagePath = _question.imagePath;
        for (int i = 0; i < _question.choices.Length; i++) { ChoiceText[i] = _question.choices[i]; }
    }
}

在我的.xaml视图代码隐藏中：

<Image Grid.Row="0"  Grid.ColumnSpan="2"
               Source="{Binding ImagePath}"
               BackgroundColor="Black"/>

<Label x:Name ="lblQuestion"
               Grid.Row="1"
               Text="{Binding QuestionText}"
               FontSize="18"
               VerticalOptions="Center"
               HorizontalOptions="Center"/>

<Button Text="{Binding ChoiceText[0]}" 
                Grid.Row="2" Grid.ColumnSpan="2"
                Style="{StaticResource defaultButtonStyle}"
                Command="{Binding SubmitAnswerCommand}" CommandParameter="1"/>
<Button Text="{Binding ChoiceText[1]}" 
                Grid.Row="3" Grid.ColumnSpan="2"
                Style="{StaticResource defaultButtonStyle}" 
                Command="{Binding SubmitAnswerCommand}" CommandParameter="2"/>
<Button Text="{Binding ChoiceText[2]}" 
                Grid.Row="4" Grid.ColumnSpan="2"
                Style="{StaticResource defaultButtonStyle}"
                Command="{Binding SubmitAnswerCommand}" CommandParameter="3"/>
<Button Text="{Binding ChoiceText[3]}" 
                Grid.Row="5" Grid.ColumnSpan="2"
                Style="{StaticResource defaultButtonStyle}" 
                Command="{Binding SubmitAnswerCommand}" CommandParameter="4"/>

<Label x:Name ="lblAnswer" IsVisible="True"
               Grid.Row="6"
               Text="{Binding AnswerText}"
               FontSize="18"
               VerticalOptions="Start"
               HorizontalOptions="Start"/>

其他可观察属性在视图中更新，没有问题。
我可以将ChoiceText[]定义为4个唯一变量，ChoiceText 1，ChoiceText 2等，但我希望能够绑定这个数组和可能更大的数组。我没绑好吗？
谢谢！abedaun