Xamarin.Forms将IsEnable设置为true不起作用

<Button x:Name="myButton" Text="Click Me" />

public MainPage()
{
    InitializeComponent();
    myButton.IsEnabled = true; // 设置按钮为启用状态
}

public class MyViewModel : INotifyPropertyChanged
{
    private bool _isButtonEnabled;
    public bool IsButtonEnabled
    {
        get => _isButtonEnabled;
        set
        {
            _isButtonEnabled = value;
            OnPropertyChanged(nameof(IsButtonEnabled));
        }
    }

    public event PropertyChangedEventHandler PropertyChanged;
    protected void OnPropertyChanged(string propertyName)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}

<Button IsEnabled="{Binding IsButtonEnabled}" Text="Click Me" />

public MainPage()
{
    InitializeComponent();
    BindingContext = new MyViewModel();
    ((MyViewModel)BindingContext).IsButtonEnabled = true;
}