动态Gridview-获取第一个子级原生广告

Question

我有一个简单的动态Gridview：

<GridView x:Name="MainGridStations" ItemsSource="{x:Bind Stations}" IsItemClickEnabled="True" ItemClick="GridView_ItemClick">
            <GridView.ItemTemplate>
                <DataTemplate x:DataType="local:Station">
                    <Grid>
                        <Grid Background="White" HorizontalAlignment="Center" Width="300" Height="200" VerticalAlignment="Center">
                            <Image x:Name="ImageStation" Source="{Binding ImageURL}"/>
                            <Grid Background="#e4f0fc" Height="65" VerticalAlignment="Bottom" Opacity="0.8">
                                <TextBlock x:Name="StationName" Text="{Binding Name}" FontWeight="Bold" Foreground="#2c9a8b" HorizontalAlignment="Center" />
                            </Grid>
                        </Grid>
                    </Grid>
                </DataTemplate>
            </GridView.ItemTemplate>
</GridView>

现在，我想在此gridview中使用原生广告。在原生广告的代码中，我需要注册包含用于点击事件等广告的广告容器。 它将始终是gridview的第一个子项，这意味着gridview中的第一个网格容器。

我已经尝试过了：

nativeAd.RegisterAdContainer(MainGridStations.ContainerFromIndex(0));

这给了我错误，它无法从 Windows.UI.Xaml.DependencyObject 转换为Windows.UI.Xaml.FrameworkElement

基本上，我期望我无法提供xaml控件的直接名称。 我该如何克服？

Answer 1

  

这给了我错误，它无法从Windows.UI.Xaml.DependencyObject转换为Windows.UI.Xaml.FrameworkElement

RegisterAdContainer方法来注册充当原生广告容器的UI元素；正确跟踪广告的展示次数和点击次数是必需的。

RegisterAdContainer的可用参数为FrameworkElement。但是MainGridStations.ContainerFromIndex(0)的值为DependencyObject。因此它将引发异常。

如果您想在第一项GridView中显示原生广告，则可以在呈现第一项时获得如下所示的第一项。

您需要继承GridView并重写MeasureOverride，ArrangeOverride方法来获取项目，然后使用 Visual Helper 获取子项。

class MyGridView : GridView
{
    private const string ImageStation = "ImageStation";
    private const string StationName = "StationName";
    private const string RootLayout = "RootLayout";
    private bool isFirst;

    NativeAdsManagerV2 myNativeAdsManager = null;
    string myAppId = "d25517cb-12d4-4699-8bdc-52040c712cab";
    string myAdUnitId = "test";

    public MyGridView()
    {
        myNativeAdsManager = new NativeAdsManagerV2(myAppId, myAdUnitId);
        myNativeAdsManager.AdReady += MyNativeAd_AdReady;
        myNativeAdsManager.ErrorOccurred += MyNativeAdsManager_ErrorOccurred;
        myNativeAdsManager.RequestAd();
    }

    private void MyNativeAdsManager_ErrorOccurred(object sender, NativeAdErrorEventArgs e)
    {

    }

    private void MyNativeAd_AdReady(object sender, NativeAdReadyEventArgs e)
    {
        NativeAdV2 nativeAd = e.NativeAd;
        AdTitle.Text = nativeAd.Title;
        Adimage.Source = nativeAd.AdIcon.Source;
        nativeAd.RegisterAdContainer(AdContainer);
    }

    protected override void PrepareContainerForItemOverride(DependencyObject element, object item)
    {
        if (this.IndexFromContainer(element) == 0)
        {
            isFirst = true;
        }
        else
        {
            isFirst = false;
        }

        base.PrepareContainerForItemOverride(element, item);
    }


    protected override Size MeasureOverride(Size availableSize)
    {
        return base.MeasureOverride(availableSize);

    }
    private Image Adimage;
    private TextBlock AdTitle;
    private Grid AdContainer;

    protected override Size ArrangeOverride(Size finalSize)
    {
        if (isFirst)
        {
            var item = this.ContainerFromIndex(0);
            AdContainer = MyFindGridViewChildByName(item, RootLayout) as Grid;
            Adimage = MyFindGridViewChildByName(item, ImageStation) as Image;
            AdTitle = MyFindGridViewChildByName(item, StationName) as TextBlock;
            isFirst = false;

        }

        return base.ArrangeOverride(finalSize);
    }

    public static DependencyObject MyFindGridViewChildByName(DependencyObject parant, string ControlName)
    {
        int count = VisualTreeHelper.GetChildrenCount(parant);

        for (int i = 0; i < count; i++)
        {
            var MyChild = VisualTreeHelper.GetChild(parant, i);
            if (MyChild is FrameworkElement && ((FrameworkElement)MyChild).Name == ControlName)
                return MyChild;

            var FindResult = MyFindGridViewChildByName(MyChild, ControlName);
            if (FindResult != null)
                return FindResult;
        }

        return null;
    }

}