如何在ListView或GridView列表项上设置AutomationProperties.AutomationId？

Question

我正在尝试学习Appium，并在Windows UWP应用程序测试中使用它。我想自动单击GridView中的项目，但不知道如何将AutomationProperties.AutomationId分配给这些动态生成的UI元素。读this SO post给了我一个线索，但对我没有用。这是我的GridView XAML：

    <GridView Name="MoviesListView" ItemsSource="{Binding Films}" Grid.Column="1" IsItemClickEnabled="True" ItemClick="MoviesListView_ItemClick">

        <GridView.ItemTemplate>
            <DataTemplate x:DataType="mov:Film">
                <RelativePanel>
                    <Image Name="posterImage" MinWidth="100" MaxWidth="150" Margin="0,0,0,10">
                        <Image.Source>
                            <BitmapImage UriSource="{Binding FullPosterPath}"/>
                        </Image.Source>
                    </Image>
                    <Border 
                            RelativePanel.AlignLeftWithPanel="True"
                            RelativePanel.AlignRightWithPanel="True"
                            RelativePanel.AlignBottomWithPanel="True">
                        <Border.Background>
                            <SolidColorBrush
                                Color="Black"
                                Opacity="0.5"/>
                        </Border.Background>
                        <TextBlock
                            Name="posterText"
                            Margin="0,0,0,10"
                            Width="100"
                            Text="{x:Bind Title}"
                            TextWrapping="Wrap"
                            HorizontalTextAlignment="Center"
                            Foreground="White"
                            Opacity="1"/>
                    </Border>
                </RelativePanel>
            </DataTemplate>
        </GridView.ItemTemplate>
        <GridView.ItemContainerStyle>
            <Style TargetType="GridViewItem">
                <Setter Property="AutomationProperties.AutomationId" Value="{Binding RelativeSource={RelativeSource Self}, Path=Film.Title}"/>
            </Style>
        </GridView.ItemContainerStyle>
    </GridView>

有人可以解释此示例中的绑定路径如何工作吗？如何分配唯一的AutomationId，例如PositionInSet？