绑定到DevExpress StockSeries2D图表

我正试图将ViewModel中的ObservableCollection数据绑定到视图中的Devexpress 2D股票图。我知道虚拟机绑定了View的DataContext，因为我将窗口的Title绑定到了虚拟机中的一个属性，并且在运行程序时它是正确的。集合被正确地实例化了，我可以看到所有的对象都被创建了，都有值，并被添加到集合中。

图表信息就是没有显示。图表没有显示应该绑定到它的信息。我猜它与XAML中的一行有关，但我不知道它是什么。

以下是输出的错误：

System.Windows.Data错误：40:BindingExpression路径错误：在"object"ChartElementPanel"上找不到"Snapshots"属性（名称=''）'。BindingExpression:Path=DataContext.Snapshots；DataItem='ChartElementPanel'（名称=''）；目标元素是"StockSeries2D"（哈希代码=24500892）；目标属性为"DataSource"（类型"对象"）

DevExpress版本为10.1.9

编辑：我想我知道问题出在哪里。StockSeries2D DataContext=DevExpress.Xpf.Charts.ChartElementPanel所以当我使用时

DataSource="{Binding Path=DataContext.Snapshots}"

它实际上指向DevExpress.Xpf.Charts.ChartElementPanel，由于它不包含快照属性，因此引发了错误。

XAML:

    <Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="200" />
        <RowDefinition Height="50" />
    </Grid.RowDefinitions>
    <dxc:ChartControl Name="chartControl1">
        <dxc:ChartControl.Diagram>
            <dxc:XYDiagram2D>
                <dxc:XYDiagram2D.Series>
                    <dxc:StockSeries2D DataSource="{Binding DataContext.Snapshots}" HighValueDataMember="High" LowValueDataMember="Low" CloseValueDataMember="Last" ArgumentScaleType="DateTime" ArgumentDataMember="TimeStamp">
                        <dxc:StockSeries2D.PointOptions>
                            <dxc:PointOptions dxc:FinancialSeries2D.ValueToDisplay="HighValue" />
                        </dxc:StockSeries2D.PointOptions>
                        <dxc:StockSeries2D.Model>
                            <dxc:ArrowsStock2DModel />
                        </dxc:StockSeries2D.Model>
                    </dxc:StockSeries2D>
                </dxc:XYDiagram2D.Series>
                <!--Region #Axis X-->
                <dxc:XYDiagram2D.AxisX>
                    <dxc:AxisX2D>
                        <dxc:AxisX2D.DateTimeOptions>
                            <dxc:DateTimeOptions Format="ShortTime" />
                        </dxc:AxisX2D.DateTimeOptions>
                    </dxc:AxisX2D>
                </dxc:XYDiagram2D.AxisX>
                <!-- End Rgion -->
                <!-- region #AxisY -->
                <dxc:XYDiagram2D.AxisY>
                    <dxc:AxisY2D>
                        <dxc:AxisY2D.Range>
                            <dxc:AxisRange dxc:AxisY2D.AlwaysShowZeroLevel="False" />
                        </dxc:AxisY2D.Range>
                    </dxc:AxisY2D>
                </dxc:XYDiagram2D.AxisY>
                <!--End Rgion-->
            </dxc:XYDiagram2D>
        </dxc:ChartControl.Diagram>
    </dxc:ChartControl>
</Grid>

ViewModel:

    public class MainWindowViewModel : INotifyPropertyChanged
{
    ObservableCollection<ISnapShot> _snapShots;
    string _windowTitle;
    public MainWindowViewModel()
    {
        _snapShots = new ObservableCollection<ISnapShot>();
        LoadSnapshots();
        WindowTitle = Snapshots.First().Symbol;
    }
    public ObservableCollection<ISnapShot> Snapshots
    {
        get { return _snapShots; }
    }
    public String WindowTitle
    {
        get { return _windowTitle; }
        set { _windowTitle = value; OnPropertyChanged("WindowTitle"); }
    }
    private void AddSnapshot(ISnapShot snapshot)
    {
        _snapShots.Add(snapshot);
    }
    private void LoadSnapshots()
    {
        int counter = 0;
        while (counter < 5)
        {
            ISnapShot s = new Snapshot()
            {
                TimeStamp = DateTime.Now,
                Symbol = "XYZ",
                High = (counter + 1) * 5,
                Low = (counter + 1) * 2,
                Last = (counter + 1) * 3
            };
            _snapShots.Add(s);
            counter++;
            Thread.Sleep(1000);
        }
    }
    public event PropertyChangedEventHandler PropertyChanged;
    void OnPropertyChanged(string prop)
    {
        if (PropertyChanged != null)
            PropertyChanged(this, new PropertyChangedEventArgs(prop));
    }
}

视图：

    public partial class MainWindow : Window
{
    private MainWindowViewModel _vm;

    public MainWindow(MainWindowViewModel vm)
    {
        InitializeComponent();
        _vm = vm;
        this.DataContext = _vm;
    }
}

应用程序：

public partial class App : Application
{
    private void OnStartup(object sender, StartupEventArgs e)
    {
        MainWindowViewModel vm = new MainWindowViewModel();
        Views.MainWindow view = new Views.MainWindow(vm); 
        view.Show();
    }
}