将可观察集合绑定到 Xaml 中的 CollectionView 不起作用

如何解决将可观察集合绑定到 Xaml 中的 CollectionView 不起作用

我有一个数据列表，我正在 ViewModel 的 ObservableCollection 属性中初始化这些数据。然后我在我的 Xaml 中绑定到这个属性。绑定上下文是通过 Prism 设置的。 （我已经测试过绑定不是问题）。当我设置 ItemSource 属性时，我得到了我的集合所用模型的输出，但是当我绑定到 DataTemplate 中的实际属性时，我没有得到任何输出。empty output on my iOS simulator image

这是我的可观察集合的示例

 public ObservableCollection<Article> Articles { get; set; }

    public HeadlinesViewModel()
    {
        Articles = new ObservableCollection<Article>();
        GetNews();
    }

    private void GetNews()
    {
        Articles.Clear();
        Articles.Add(new Article
        {

            Author = "",Title = "Chris Doyle resigns from Jacksonville Jaguars coaching staff after backlash,per report - CBS Sports",Description = "Doyle's resignation comes just one day after his hiring was announced",Url = "https://www.cbssports.com/nfl/news/chris-doyle-resigns-from-jacksonville-jaguars-coaching-staff-after-backlash-per-report/",UrlToImage = "https://sportshub.cbsistatic.com/i/r/2020/06/06/0cc1de7f-e541-4d15-997b-3a07fd108595/thumbnail/1200x675/e06338e0fc01ba092ff7d2db49136c47/chris-doyle.jpg",PublishedAt = "2021-02-13T05:06:00Z",Content = "Chris Doyle has resigned from the Jacksonville Jaguars coaching staff just one day after his controversial hiring was announced,according to ESPN's Adam Schefter. Doyle was hired by new head coach U… [+3590 chars]",Source = "CBS Sports"
        });
        Articles.Add(new Article
        {

            Author = "By <a href=\"/profiles/james-griffiths\">James Griffiths</a> and <a href=\"/profiles/brett-mckeehan\">Brett McKeehan</a>,CNN",Title = "The latest on the coronavirus pandemic and vaccines: Live updates - CNN ",Description = "The coronavirus pandemic has brought countries to a standstill. Meanwhile,vaccinations have already started in some countries as cases continue to rise. Follow here for the latest.",Url = "https://www.cnn.com/world/live-news/coronavirus-pandemic-vaccine-updates-02-13-21/index.html",UrlToImage = "https://cdn.cnn.com/cnnnext/dam/assets/200213175739-03-coronavirus-0213-super-tease.jpg",PublishedAt = "2021-02-13T05:00:00Z",Content = "The US state of California is adding millions of people to its Covid-19 vaccination priority list,including residents at high risk with developmental and other disabilities\" and those with serious u… [+2465 chars]",Source = "CNN"
        });

}

这是我的 Xaml 示例

<Grid Grid.Row="1" Margin="0,30,0">
            <Grid.RowDefinitions>
                <RowDefinition Height="Auto" />
                <RowDefinition Height="*" />
            </Grid.RowDefinitions>
            <StackLayout Orientation="Horizontal">
                <Label
                    FontFamily="Roboto-Black"
                    FontSize="24"
                    HorizontalOptions="StartAndExpand"
                    Text="US Politics"
                    VerticalOptions="Center" />
                <Frame
                    Padding="8,4"
                    BackgroundColor="#EEEEEE"
                    CornerRadius="8"
                    HasShadow="False"
                    HorizontalOptions="End"
                    VerticalOptions="Center">
                    <Label
                        FontFamily="OpenSans-SemiBold"
                        FontSize="14"
                        Text="Show all" />
                </Frame>
            </StackLayout>
            <CollectionView
                Grid.Row="1"
                Margin="0,10"
                HeightRequest="250"
                HorizontalScrollBarVisibility="Never"
                ItemsSource="{Binding Articles}"
                WidthRequest="100">
                <CollectionView.ItemTemplate>
                    <DataTemplate>
                        <Image Source="{Binding UrlToImage}" />
                    </DataTemplate>
                </CollectionView.ItemTemplate>
            </CollectionView>

        </Grid>