C# WPF SparrowChart绑定问题

我无法进行绑定以获取SparrowChart控件的数据：

  <sparrow:SparrowChart>
        <sparrow:SparrowChart.XAxis>
            <sparrow:LinearXAxis/>
        </sparrow:SparrowChart.XAxis>
        <sparrow:SparrowChart.YAxis>
            <sparrow:LinearYAxis/>
        </sparrow:SparrowChart.YAxis>
        <sparrow:LineSeries PointsSource="{Binding PlotValuesList,diagnostics:PresentationTraceSources.TraceLevel=High}" XPath="X" YPath="Y"/>
    </sparrow:SparrowChart>

这是我遵循的指导原则： 那么，这是怎么回事，因为即使我提供了一些数据，图表也不会出现

    System.Windows.Data Warning: 56 : Created BindingExpression (hash=28447227) for Binding (hash=64529095)
System.Windows.Data Warning: 58 :   Path: 'PlotValuesList'
System.Windows.Data Warning: 60 : BindingExpression (hash=28447227): Default mode resolved to OneWay
System.Windows.Data Warning: 61 : BindingExpression (hash=28447227): Default update trigger resolved to PropertyChanged
System.Windows.Data Warning: 62 : BindingExpression (hash=28447227): Attach to Sparrow.Chart.LineSeries.PointsSource (hash=25485653)
System.Windows.Data Warning: 67 : BindingExpression (hash=28447227): Resolving source 
System.Windows.Data Warning: 70 : BindingExpression (hash=28447227): Found data context element: LineSeries (hash=25485653) (OK)
System.Windows.Data Warning: 78 : BindingExpression (hash=28447227): Activate with root item <null>
System.Windows.Data Warning: 106 : BindingExpression (hash=28447227):   Item at level 0 is null - no accessor
System.Windows.Data Warning: 80 : BindingExpression (hash=28447227): TransferValue - got raw value {DependencyProperty.UnsetValue}
System.Windows.Data Warning: 88 : BindingExpression (hash=28447227): TransferValue - using fallback/default value <null>
System.Windows.Data Warning: 89 : BindingExpression (hash=28447227): TransferValue - using final value <null>