ReactiveUI - ViewCell结合

Question

我正在尝试复制101例 of ReactiveUI并使其适应Xamarin Forms。

我使用自定义的ViewCell，但不能以ReactiveUI的方式绑定它：

public partial class FlickrPhotoCell : ViewCell, IViewFor<FlickrPhotoModel>
{
    public FlickrPhotoCell()
    {
        InitializeComponent();
        this.Bind(ViewModel, vm => vm.Title, v => v.TitleLabel.Text);
        this.Bind(ViewModel, vm => vm.Description, v => v.DescriptionLabel.Text);
        this.Bind(ViewModel, vm => vm.Url, v => v.UrlImage.Source, null, new CustomConverter());
    }

    //The rest of the code below is plumbing:

    public static readonly BindableProperty ViewModelProperty = BindableProperty.Create(nameof(ViewModel), typeof(FlickrPhotoModel), typeof(FlickrPhotoCell));

    public FlickrPhotoModel ViewModel
    {
        get { return (FlickrPhotoModel)GetValue(ViewModelProperty); }
        set { SetValue(ViewModelProperty, value); }
    }

    object IViewFor.ViewModel
    {
        get { return ViewModel; }
        set { ViewModel = (FlickrPhotoModel)value; }
    }
}

然而，如果我按照通常的Xamarin Forms方式做这件事的话，效果会很好：

public FlickrPhotoCell()
    {
        InitializeComponent();
        TitleLabel.SetBinding<FlickrPhotoModel>(Label.TextProperty, x => x.Title);
        DescriptionLabel.SetBinding<FlickrPhotoModel>(Label.TextProperty, x => x.Description);
        UrlImage.SetBinding<FlickrPhotoModel>(Image.SourceProperty, x => x.Url);
    }

Answer 1

我认为一个不同之处是，Xamarin方法使用的是BindingContext，而ReactiveUI方法使用的是纯ViewModel。所以我的第一个猜测是ViewModel属性没有被设置。也许试着将BindingContext绑定到ViewModel？或者重写OnBindingContext，更改并在那里设置ViewModel，以查看它是否有效。