在Listpicker中加载数据

Question

请问我在listpicker控件中显示数据的方式有问题。我实际上从一个Web服务加载，但我后来尝试使用静态数据，但我发现我无法加载我的静态数据。它使我的MVVM出错。我粘贴了下面的代码。

我的模特课

public class ContinentSelect
{
    public int ID { get; set; }
    public string Name { get; set; }
}

ViewModels

public class ContinentViewModel : INotifyPropertyChanged
{
    private ContinentSelect continent;

    // public ContinentViewModel() { }

    public ContinentViewModel(ContinentSelect continent)
    {
        this.continent = continent;
    }

    public string ID
    {
        get
        {
            return continent.ID.ToString();
        }
        set
        {
            if (value != continent.ID.ToString())
            {
                continent.ID =  int.Parse(value);
                NotifyPropertyChanged("ID");
            }
        }
    }

    public string Name
    {
        get
        {
            return continent.Name;
        }
        set
        {
            if (value != continent.Name)
            {
                continent.Name = value;
                NotifyPropertyChanged("Name");
            }
        }
    }

    //This would notify the view when there is a direct change in the values of the list items
    public event PropertyChangedEventHandler PropertyChanged;
    private void NotifyPropertyChanged(String propertyName)
    {
        PropertyChangedEventHandler handler = PropertyChanged;
        if (null != handler)
        {
            handler(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}

public class MainContinentViewModel  : INotifyPropertyChanged
{
    IRegionService regionservice = null;

    public MainContinentViewModel()
    {
        this.Items = new ObservableCollection<ContinentViewModel>();
        regionservice = new RegionService();
    }

    public ObservableCollection<ContinentViewModel> Items { get; private set; }

    private string _sampleProperty = "Sample Runtime Property Value";
    /// <summary>
    /// Sample ViewModel property; this property is used in the view to display its value using a Binding
    /// </summary>
    /// <returns></returns>
    public string SampleProperty
    {
        get
        {
            return _sampleProperty;
        }
        set
        {
            if (value != _sampleProperty)
            {
                _sampleProperty = value;
                NotifyPropertyChanged("SampleProperty");
            }
        }
    }

    /// <summary>
    /// Sample property that returns a localized string
    /// </summary>
    public string LocalizedSampleProperty
    {
        get
        {
            return AppResources.SampleProperty;
        }
    }

    public bool IsDataLoaded
    {
        get;
        private set;
    }

    public void LoadData() 
    {
       // this.CollectContinents();

        ContinentSelect continent = new ContinentSelect() { ID = 0, Name = "Jide" };
        ContinentViewModel viewmodel = new ContinentViewModel(continent);
        Items.Add(viewmodel);
    }

    public event PropertyChangedEventHandler PropertyChanged;
    private void NotifyPropertyChanged(String propertyName)
    {
        PropertyChangedEventHandler handler = PropertyChanged;
        if (null != handler)
        {
            handler(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}

然后我的xaml视图如下。我跳过一些代码使其可读且简短

<phone:PhoneApplicationPage
    x:Class="JizB2c.UserLocation"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
    xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    d:DataContext="{d:DesignData SampleData/ContinentSampleData.xaml}"
    FontFamily="{StaticResource PhoneFontFamilyNormal}"
    FontSize="{StaticResource PhoneFontSizeNormal}"
    Foreground="{StaticResource PhoneForegroundBrush}"
    SupportedOrientations="Portrait" Orientation="Portrait"
    mc:Ignorable="d"
    shell:SystemTray.IsVisible="True"
    xmlns:toolkit="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone.Controls.Toolkit" 
    Loaded="UserLocationPage_Loaded">

    <toolkit:ListPicker 
                Grid.Column="0"
                Grid.Row="0"
                Grid.ColumnSpan="2"
                x:Name="listPicker"
                Header="Choose Continent">
        <toolkit:ListPicker.ItemTemplate>
            <DataTemplate>
                <StackPanel Margin="0,0,0,17" Orientation="Horizontal">
                    <TextBlock Text="{Binding ID}" TextWrapping="Wrap" Style="{StaticResource PhoneTextExtraLargeStyle}"/>
                    <TextBlock Text="{Binding Name}" TextWrapping="Wrap" Margin="12,-6,12,0" Style="{StaticResource PhoneTextSubtleStyle}"/>
                </StackPanel>
            </DataTemplate>
        </toolkit:ListPicker.ItemTemplate>
    </toolkit:ListPicker>
</phone:PhoneApplicationPage>