如何控制 System.Web.UI.DataVisualization.Charting 中自定义标签的宽度？

Question

我有一些代码可以使用旧的 Dundas 图表组件（版本 7）生成类似温度计的简单图表。这是代码：

'Imports Dundas, Dundas.Charting, Dundas.Charting.WebControl
Public Shared Function GetSimpleThermometerChart(ByVal currentValue As Integer, ByVal goalValue As Integer) As Stream
    If goalValue < 0 Then goalValue = 0
    If currentValue < 0 Then currentValue = 0
    If currentValue > goalValue Then currentValue = goalValue

    Dim red = Drawing.Color.FromArgb(255, 192, 80, 77)
    Dim chart1 = New Chart()
    Dim series1 = chart1.Series.Add("Series1")
    Dim defaultArea = chart1.ChartAreas.Add("Default")

    With chart1
        .Legends(0).Enabled = False
        .Height = New System.Web.UI.WebControls.Unit(200)
        .Width = New System.Web.UI.WebControls.Unit(275)
    End With

    With defaultArea
        .BorderStyle = ChartDashStyle.Solid

        ' Y-axis
        .AxisY2.MajorGrid.Enabled = True
        .AxisY2.Interval = goalValue / 2
        .AxisY2.Maximum = goalValue
        .AxisY2.LabelStyle.Interval = goalValue
        .AxisY2.MajorTickMark.Interval = goalValue / 2
        .AxisY2.MajorTickMark.Enabled = False
        .AxisY2.LabelStyle.Font = New System.Drawing.Font("Tahoma", 10)
        .AxisY2.CustomLabels.Add((goalValue * 0.45), (goalValue * 0.55), String.Format(" You're half way to your goal of {0}!", goalValue))
        .AxisY2.CustomLabels.Add((goalValue * 0.9), (goalValue * 0.99), String.Format(" You met the goal of {0}!!!", goalValue))

        ' X-axis
        .AxisX.MajorGrid.Enabled = False
        .AxisX.Maximum = 1
        .AxisX.Minimum = 0.8
        .AxisX.LabelStyle.Enabled = False
        .AxisX.MajorTickMark.Enabled = False
    End With

    ' Populate series data
    Dim pt1 = New DataPoint(1, currentValue)
    series1.Points.Add(pt1)

    With series1
        .Type = SeriesChartType.Column
        .Color = red
        .YAxisType = AxisType.Secondary
    End With

    Dim memStrm As New MemoryStream()
    chart1.Save(memStrm, ChartImageFormat.Png)
    memStrm.Position = 0
    Return memStrm
End Function

此代码生成的图表在左侧显示了一个漂亮的小图表，在右侧 Y 轴上显示了完整的、未截断的自定义标签文本。

Microsoft 购买了 Dundas 图表组件并将其集成到 .NET 4.0 框架中，因此我一直在测试图表的功能是否相同。当然，我立刻就遇到了矛盾。在将上面的代码转换为新的 System.Web.UI.DataVisualization.Charting 等效代码时，我得到了以下代码：

'Imports System.Web.UI.DataVisualization.Charting
Public Shared Function GetSimpleThermometerChart(ByVal currentValue As Integer, ByVal goalValue As Integer) As Stream
    If goalValue < 0 Then goalValue = 0
    If currentValue < 0 Then currentValue = 0
    If currentValue > goalValue Then currentValue = goalValue

    Dim red = Drawing.Color.FromArgb(255, 192, 80, 77)
    Dim chart1 = New Chart()
    Dim series1 = chart1.Series.Add("Series1")
    Dim defaultArea = chart1.ChartAreas.Add("Default")

    With chart1
        .Height = New System.Web.UI.WebControls.Unit(200)
        .Width = New System.Web.UI.WebControls.Unit(275)
    End With

    With defaultArea
        '.InnerPlotPosition.Height = 100 ' YUCK!  Why???
        '.InnerPlotPosition.Width = 20  ' YUCK!  Why???

        .BorderDashStyle = ChartDashStyle.Solid

        ' Y-axis
        .AxisY2.MajorGrid.Enabled = True
        .AxisY2.Interval = goalValue / 2
        .AxisY2.Maximum = goalValue
        .AxisY2.LabelStyle.Interval = goalValue
        .AxisY2.MajorTickMark.Interval = goalValue / 2
        .AxisY2.MajorTickMark.Enabled = False
        .AxisY2.LabelStyle.Font = New System.Drawing.Font("Tahoma", 10)
        .AxisY2.CustomLabels.Add((goalValue * 0.45), (goalValue * 0.55), String.Format(" You're half way to your goal of {0}!", goalValue))
        .AxisY2.CustomLabels.Add((goalValue * 0.9), (goalValue * 0.99), String.Format(" You met the goal of {0}!!!", goalValue))

        ' X-axis
        .AxisX.MajorGrid.Enabled = False
        .AxisX.Maximum = 1
        .AxisX.Minimum = 0.8
        .AxisX.LabelStyle.Enabled = False
        .AxisX.MajorTickMark.Enabled = False
    End With

    ' Populate series data
    Dim pt1 = New DataPoint(1, currentValue)
    series1.Points.Add(pt1)

    With series1
        .ChartType = SeriesChartType.Column
        .Color = red
        .YAxisType = AxisType.Secondary
    End With

    Dim memStrm As New MemoryStream()
    chart1.SaveImage(memStrm, ChartImageFormat.Png)
    memStrm.Position = 0
    Return memStrm
End Function

现在，不是缩放图表以显示我的自定义标签的全文，而是图表变得更宽，文本被省略号截断。我一直在寻找如何从 Dundas 获得行为但没有运气。我尝试了各种设置，例如：

With defaultArea
   .AxisY2.IsLabelAutoFit = True
   .AxisY2.LabelAutoFitStyle = LabelAutoFitStyles.None
   .AxisY2.LabelStyle.TruncatedLabels = False
End With

这些不起作用。我唯一能够开始工作的事情就是如果我这样做：

With defaultArea
   .InnerPlotPosition.Height = 100 ' YUCK!  Why???  Seems brittle...
   .InnerPlotPosition.Width = 20 ' YUCK!  Why???  Seems brittle...
End With

这段代码的问题在于我更关心文本的大小而不是图表的大小，并且我希望文本始终显示。尽管这个人为示例中的文本是硬编码的，但在实际系统中不会这样，所以我真的需要动态的图形大小，以便自定义标签始终显示文本而不缩放字体大小。有关如何模仿旧 Dundas 组件的默认行为的任何建议？

Answer 1

我知道您试图找到与 MS 图表控件一起使用的 right 属性是什么意思。遍历对象层次结构可能会很痛苦，但我认为您正在寻找的是以下代码：

Me.Chart1.ChartAreas("Default").AxisY2.LabelStyle.Font = New System.Drawing.Font("Arial", 6)