用net和owc11在画句柄时遇到的问题

最近在用owc11做数据统计分析时遇到一个有意思的问题。源码如下：

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        Dim startdate As Date
        Dim enddate As Date = Now()

        startdate = enddate.AddDays(-1)
        'classstring = "a" + Chr(9) + "b" + Chr(9) + "c"
        ' valuesstring = "1" + Chr(9) + "20" + Chr(9) + "30"
        '在此处放置初始化页的用户代码
        readdata()
        Response.Buffer = True
        Response.ContentType = "image/gif"
        Dim ChartSpace1 As OWC11.ChartSpace
        ChartSpace1 = New OWC11.ChartSpaceClass
        Dim chart1 As OWC11.ChChart
        Dim DataLabels As OWC11.ChDataLabels
        chart1 = ChartSpace1.Charts.Add(0)
        ChartSpace1.HasChartSpaceLegend = True
        ChartSpace1.ChartSpaceLegend.Position = ChartLegendPositionEnum.chLegendPositionBottom
        ChartSpace1.HasChartSpaceTitle = True
        ChartSpace1.ChartSpaceTitle.Caption = "从" + startdate.ToLongDateString + "到" + enddate.ToLongDateString + "数据集访问分析图"
        chart1.Type = ChartChartTypeEnum.chChartTypePie
        chart1.SeriesCollection.Add(0)
        'chart1.SeriesCollection(0).SetData(OWC11.ChartDimensionsEnum.chDimSeriesNames, OWC11.ChartSpecialDataSourcesEnum.chDataLiteral, "aa")
        chart1.SeriesCollection(0).SetData(OWC11.ChartDimensionsEnum.chDimCategories, OWC11.ChartSpecialDataSourcesEnum.chDataLiteral, classstring)
        chart1.SeriesCollection(0).SetData(OWC11.ChartDimensionsEnum.chDimValues, OWC11.ChartSpecialDataSourcesEnum.chDataLiteral, valuesstring)
        DataLabels.Position = ChartDataLabelPositionEnum.chLabelPositionAutomatic
        Response.BinaryWrite(ChartSpace1.GetPicture("gif", 550, 500))
        Response.End()
    End Sub

 

主要是这句

DataLabels.Position = ChartDataLabelPositionEnum.chLabelPositionAutomatic

datalabels的定位属性只能是自动和居中不能是别的。一用别的类型就报错说参数无效。网上查了一下很多人说也遇到了这个问题，但是没有人能解决，估计是微软的疏忽还是什么原因。。。期待有人能解决这个问题。