在GridView数据模板内的组合框中填充组合框项目和SelectedValue

我正在开发一个Windows 10通用应用程序,在GridView数据模板中的组合框(组合框项目和SelectedValue)中填充项目时遇到问题。我似乎找不到这样做的方法。

详情如下:

我有个目标( UserData )可以包含另一个对象的多个实例的( List<VisitedCity> ). 在XAML页面上,的多个实例 VisitedCity 显示在垂直网格视图上。

的每个实例 访问城市 可以包含 CityName 和 VisitedDate . 在XAML页面上,CityName显示在组合框中,访问日期显示在每个GridViewItem内的日期选择器上。

什么不起作用:

显示每个访问城市的选定城市名称的组合框需要从 List<string> 变量(以便用户可以更改)和组合框SelectedValue需要从curretUserData对象的 VisitedCities 属性(CityName属性)。

我正在尝试使用 x:Bind 在XAML上,以最小化代码落后。

我已经包含了我为解决此问题而使用的示例应用程序中的所有代码,并且还指出了我在XAML上遇到问题的代码行。

请注意,这是以VisitedCities为例的大型应用程序的高度简化部分,以便更好地演示问题。感谢您的帮助和投入!

这是我的班级档案:

namespace mySampleApp
{
    class UserData
    {
        public string FullName { get; set; }
        public List<VisitedCity> VisitedCities { get; set; }
    }

    class VisitedCity
    {
        public string CityName { get; set; }
        public DateTime VisitedDate { get; set; }

    }

    class CityNameManager
    {
        public static List<string> GetListOfCitiesFromServer()
        {
            List<string> listOfCities = new List<string>();

            //code will be here to get the latest list from the server. for now we will manually return a list

            listOfCities.Add("City1");
            listOfCities.Add("City2");
            listOfCities.Add("City3");
            listOfCities.Add("City4");
            listOfCities.Add("City5");

            return listOfCities;

        }
    }
}

这是我的XAML:

<Page
    x:Class="mySampleApp.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:mySampleApp"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d">

    <Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">

        <Grid.RowDefinitions>
            <RowDefinition  Height="Auto"/>
            <RowDefinition  Height="Auto"/>
            <RowDefinition  Height="Auto"/>
            <RowDefinition  Height="Auto"/>
            <RowDefinition  Height="Auto"/>
        </Grid.RowDefinitions>

        <TextBox x:Name="txtFirstName" Grid.Row="0" Header="Enter Your Name" Text="{x:Bind curretUserData.FullName}"/>

        <TextBlock x:Name="label1" Grid.Row="1" TextWrapping="WrapWholeWords" Text="Please select all cities you have visited during the last 5 years. For each city please enter the data visited. If you visited a city multiple times, please have multiple entries for each time indicating the date visited each time." />

        <TextBlock x:Name="label2" Grid.Row="2" TextWrapping="WrapWholeWords" Text="Press the + button to add rows as needed. " />

        <Button x:Name="myButton" Grid.Row="3" Content="+" Click="myButton_Click" />

        <GridView x:Name="myGridView" Grid.Row="4" HorizontalContentAlignment="Stretch" SelectionMode="None" ItemsSource="{x:Bind curretUserData.VisitedCities}">
            <GridView.ItemsPanel>
                <ItemsPanelTemplate>
                    <ItemsStackPanel Orientation="Vertical" />
                </ItemsPanelTemplate>
            </GridView.ItemsPanel>

            <GridView.ItemContainerStyle>
                <Style TargetType="GridViewItem">
                    <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
                    <Setter Property="HorizontalAlignment" Value="Stretch"/>
                </Style>
            </GridView.ItemContainerStyle>

            <GridView.ItemTemplate>
                <DataTemplate x:DataType="local:VisitedCity">
                    <Grid HorizontalAlignment="Stretch">

                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="Auto" />
                            <ColumnDefinition Width="*" />
                        </Grid.ColumnDefinitions>

                        <!-- This is the line of code which has issues-->
                        <ComboBox Grid.Column="0" x:Name="myTemplateComboBox"  ItemsSource="{local:CityList ??? }" SelectedValue="{x:Bind CityName ??? }" HorizontalAlignment="Stretch"  />

                        <DatePicker Grid.Column="1" x:Name="myTemplateDatePicker" Date="{x:Bind VisitedDate }" />

                    </Grid>
                </DataTemplate>
            </GridView.ItemTemplate>
        </GridView>
    </Grid>
</Page>

下面是我的代码:

namespace mySampleApp
{
    /// <summary>
    /// An empty page that can be used on its own or navigated to within a Frame.
    /// </summary>
    public sealed partial class MainPage : Page
    {
        //variables to use in XAML x:Bind
        private UserData curretUserData = new UserData();
        private List<string> CityList = new List<string>();

        public MainPage()
        {
            //get latest list of cities from the server
            CityList = CityNameManager.GetListOfCitiesFromServer();

            //add sample data to show on the page for demo
            curretUserData.FullName = "Sample User";
            List<VisitedCity> sampleUserVisitedCities = new List<VisitedCity>();
            sampleUserVisitedCities.Add(new VisitedCity {CityName = "City1", VisitedDate=DateTime.Parse("2/2/2016") });
            sampleUserVisitedCities.Add(new VisitedCity {CityName = "City2", VisitedDate = DateTime.Parse("2/2/2015") });
            curretUserData.VisitedCities = sampleUserVisitedCities;

            this.InitializeComponent();
        }

        private void myButton_Click(object sender, RoutedEventArgs e)
        {
            //add a new row
            GridViewItem gridViewItem = new GridViewItem();
            gridViewItem.ContentTemplate = myGridView.ItemTemplate;
            myGridView.Items.Add(gridViewItem);
        }
    }
}