c# devexpress wpf charts问题

<Window x:Class="ChartsDemo.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:dxc="http://schemas.devexpress.com/winfx/2008/xaml/charts" 

    Title="Window1" Height="300" Width="300">

    <Grid>
        <dxc:ChartControl Name="chart" BorderThickness="0" MouseMove="chart_MouseMove" MouseLeave="chart_MouseLeave" >
            <dxc:ChartControl.Diagram>
                <dxc:XYDiagram2D>
                </dxc:XYDiagram2D>
            </dxc:ChartControl.Diagram>
        </dxc:ChartControl>
    </Grid>
</Window>


错误 4 未找到类型“dxc:XYDiagram2D”。请确保不缺少程序集引用，并且已生成所有引用的程序集。 C:\Users\GINO\Documents\Visual Studio 2008\Projects\ChartsDemo\ChartsDemo\Window1.xaml 11 18 ChartsDemo

引用的DLL是8.2的

补充：.NET技术 ,  C#