ASP.NET MS 图表控件：数据点插入错误。这个数据系列只能设置2个Y值。参数名称：数据源

Question

我的 MS 图表控件出现此错误：

Data points insertion error. Only 2 Y values can be set for this data series. Parameter name: dataSource

它出现在我下面代码的 chartPriceHistory_STATIC.DataBind() 行。

我认为这与我添加点的方式有关(AddXY)，但无法弄清楚它是什么。

我尝试了这两个代码选项：

选项 1 chartPriceHistory_STATIC.Series(seriesName).Points.AddXY(get3LetterMonth(CDate(row("createdate")).Month) + "-" + CDate(row("createdate")).Year.ToString, {CType(row("price"), Integer), totalobjects})

选项 2 chartPriceHistory_STATIC.Series(seriesName).Points.AddXY(get3LetterMonth(CDate(row("createdate")).Month) + "-" + CDate(row("createdate" )).Year.ToString, CType(行("price"), 整数))<br> chartPriceHistory_STATIC.Series("totalobjects").Points.AddXY(get3LetterMonth(CDate(row("createdate")).Month) + "-" + CDate(row("createdate") ).Year.ToString, totalobjects)

两者都抛出相同的错误...我错过了什么？

    Dim mycommand As New SqlCommand("SELECT avgprice, createdate, totalobjects FROM avgprices", myConnection)
    Dim dtPrices As New System.Data.DataTable
    dtPrices.Columns.Add("price", System.Type.GetType("System.Int32"))
    dtPrices.Columns.Add("createdate", System.Type.GetType("System.DateTime"))
    dtPrices.Columns.Add("totalobjects", System.Type.GetType("System.Int32"))

    Dim dr As System.Data.DataRow

    Try
        Dim reader As SqlDataReader = mycommand.ExecuteReader()
        While reader.Read
            dr = dtPrices.NewRow()
            dr("price") = reader("price")
            dr("createdate") = reader("createdate")
            dr("totalobjects") = reader("totalobjects")
            dtPrices.Rows.Add(dr)
        End While
    Catch ex As Exception
    End Try

    ' Initializes a New instance of the DataSet class
    Dim myDataSet As DataSet = New DataSet()

    'Adds rows in the DataSet
    myDataSet.Tables.Add(dtPrices)

    chartPriceHistory_STATIC.Series.Clear()

    Dim seriesName As String = "Avg price"
    chartPriceHistory_STATIC.Series.Add(seriesName)
    chartPriceHistory_STATIC.Series(seriesName).XValueMember = "Date"

    chartPriceHistory_STATIC.ChartAreas.Add("ChartArea1")

    chartPriceHistory_STATIC.Series(seriesName).YValuesPerPoint = 2

    chartPriceHistory_STATIC.ChartAreas(0).AxisY.MajorGrid.Enabled = True
    chartPriceHistory_STATIC.ChartAreas(0).AxisY.Title = "Price"

    Dim totalobjects As Integer = 1


    chartPriceHistory_STATIC.Series.Add("Series2")
    chartPriceHistory_STATIC.Series("Series2").YAxisType = AxisType.Secondary
    chartPriceHistory_STATIC.Series("Series2").XValueMember = "Date"
    chartPriceHistory_STATIC.Series("Series2").YValueMembers = "totalobjects"
    chartPriceHistory_STATIC.Series("Series2").Name = "totalobjects"
    chartPriceHistory_STATIC.Series("totalobjects").ChartType = SeriesChartType.Line
    chartPriceHistory_STATIC.Series("totalobjects").ToolTip = "Total objects"


    chartPriceHistory_STATIC.Series(0).YAxisType = AxisType.Primary
    chartPriceHistory_STATIC.Series(1).YAxisType = AxisType.Secondary


    For Each row As DataRow In myDataSet.Tables(0).Rows
        totalobjects += 1

        'I tried: these 2 options, both generate the same error
        chartPriceHistory_STATIC.Series(seriesName).Points.AddXY(get3LetterMonth(CDate(row("createdate")).Month) + "-" + CDate(row("createdate")).Year.ToString, {CType(row("price"), Integer), totalobjects})

        chartPriceHistory_STATIC.Series(seriesName).Points.AddXY(get3LetterMonth(CDate(row("createdate")).Month) + "-" + CDate(row("createdate")).Year.ToString, CType(row("price"), Integer))
        chartPriceHistory_STATIC.Series("totalobjects").Points.AddXY(get3LetterMonth(CDate(row("createdate")).Month) + "-" + CDate(row("createdate")).Year.ToString, totalobjects)
    Next

    chartPriceHistory_STATIC.DataSource = myDataSet
    chartPriceHistory_STATIC.DataBind()

Answer 1

而不是使用 Points.AddXY 方法尝试通过新 class 创建点并将它们添加到图表

foreach (var result in data)
                {
                    point = new DataPoint();
                    point.AxisLabel = result.XData;

                    point.YValues = new double[] { result.YData };

                    point.Color = result.Color;
                    seriesDetail.Points.Add(point);

                }

Answer 2

您还需要为 "Avg price" 系列设置 YValueMembers。

添加这一行（使用您想要在 Y 轴上绘制的任何字符串）：

chartPriceHistory_Static.Series(seriesName).YValueMembers = "totalobjects"

在这一行之前添加：

chartPriceHistory_Static.Series(seriesName).YValuesPerPoint = 2

此外，您的 date/createdate 列名称不一致 - 在更正之前您将看不到图表。

如果您只添加 1 个 YValue，您可以再次将 YValuesPerPoint 降低到 1，不会出错。

已测试。工作正常。干杯！

ASP.NET MS 图表控件：数据点插入错误。这个数据系列只能设置2个Y值。参数名称：数据源

ASP.NET MS chart control: Data points insertion error. Only 2 Y values can be set for this data series. Parameter name: dataSource

vb.net

asp.net

data-visualization

microsoft-chart-controls