ASP.NET 图表饼图 - 每片的内部和外部标签

ASP.NET Charting Pie Chart - both inside and outside label per slice

在现有应用程序中(Web 表单,但底层 Microsoft Charting 堆栈与 winforms/webforms/razor 图表基本相同)我有饼图,每个切片都有以下业务数据:

  1. 价值
  2. 标签
  3. 颜色(用于分类,多个切片相同颜色)

要求是一张图表,所有信息布局在一个图表中,如下所示(模型):

使用 Series/Points 上的 CustomProperties,我可以使用 Inside

显示每个数据点

或外部标签:

但不是两者。我能以某种方式让饼图显示 both 每个数据点的内部和外部标签吗?

我意识到这是一个边缘案例(通常你会使用图例+颜色来可视化它,但我们已经使用颜色来分类)。我宁愿避免首先渲染到位图并在上面手动渲染标签文本(因为有适当的机制可以将图表流式传输到网页和生成的文档)。

创建两个系列和两个图表区域并将它们叠加:

ASPX:

<asp:Chart ID="Chart1" runat="server">
    <series>
        <asp:Series ChartType="Pie" 
            Name="Series1" 
            CustomProperties="PieLabelStyle=Inside, PieStartAngle=270" 
            BorderColor="White" 
            ChartArea="ChartArea1">
        </asp:Series>
        <asp:Series ChartType="Pie" 
            Name="Series2" 
            CustomProperties="PieLabelStyle=Outside, PieStartAngle=270" 
            ChartArea="ChartArea2">
        </asp:Series>
    </series>
    <chartareas>
        <asp:ChartArea Name="ChartArea1" >
            <InnerPlotPosition Height="95" Width="45.98404" X="27.00798" Y="2.50000072" />
        </asp:ChartArea>
        <asp:ChartArea Name="ChartArea2" 
            AlignWithChartArea="ChartArea1"
            AlignmentOrientation="All"
            BackColor="Transparent">
            <InnerPlotPosition Height="95" Width="45.98404" X="27.00798" Y="2.50000072" />
        </asp:ChartArea>
        </chartareas>
</asp:Chart>

CS:

protected void Page_Load(object sender, EventArgs e)
{
    List<MyDataModel> data = new List<MyDataModel> {
        new MyDataModel { Color = Color.LightBlue, Label = "Value 1", Value = 100 },
        new MyDataModel { Color = Color.LightBlue, Label = "Value 2", Value = 100 },
        new MyDataModel { Color = Color.LightBlue, Label = "Value 3", Value = 100 },
        new MyDataModel { Color = Color.Blue, Label = "Value 4", Value = 100 },
        new MyDataModel { Color = Color.Blue, Label = "Value 5", Value = 400 },
    };

        foreach (MyDataModel dm in data)
        {
            Chart1.Series[0].Points.Add(new DataPoint
            {
                Color = dm.Color,
                Label = dm.Value.ToString(),
                YValues = new double[] { dm.Value }
            });

            Chart1.Series[1].Points.Add(new DataPoint
            {
                Color = Color.Transparent,
                Label = dm.Label,
                YValues = new double[] { dm.Value }
            });
        }
}