圆环图

圆环图 是由 Doughnut3DSeriesView 对象来表示的，此对象属于饼、圆环和漏斗系列视图。当需要比较相同系列中不同点参数的百分比取值时、并且以易于理解的圆环切块来说明这些取值时，使用这种视图。另外，三维外观使旋转图表变得可能，从而以一种吸引眼球且易于理解的方式来放置圆环切块。

在下面的插图中显示了一个圆环图。

下表列出了这种图表类型的主要特征。

特征	取值
系列视图类型	Doughnut3DSeriesView
图象类型	SimpleDiagram3D
每个数据点的参数个数	1
每个数据点的取值个数	1

注意
要获得关于哪些图表类型可以与圆环图组合使用的信息，请参阅组合使用不同的系列视图文档。

下面的示例演示了在运行时刻如何创建 ChartControl (拥有一个 Doughnut3DSeriesView 类型的系列)，设置它的常规属性，并把图表添加到窗体中。在继续本示例之前，首先要在 Visual Studio 中创建一个 Windows 窗体应用程序，并把所有必需的程序集包含到项目的“引用”列表中。

然后，把下列代码添加到 Form.Load 事件处理程序。

C#	复制代码
using System; using System.Windows.Forms; using DevExpress.XtraCharts; // ... private void Form1_Load(object sender, EventArgs e) { // Create an empty chart. ChartControl DoughnutChart3D = new ChartControl(); // Create a doughnut series. Series series1 = new Series("Doughnut Series 1", ViewType.Doughnut3D); // Populate the series with points. series1.Points.Add(new SeriesPoint("Russia", 17.0752)); series1.Points.Add(new SeriesPoint("Canada", 9.98467)); series1.Points.Add(new SeriesPoint("USA", 9.63142)); series1.Points.Add(new SeriesPoint("China", 9.59696)); series1.Points.Add(new SeriesPoint("Brazil", 8.511965)); series1.Points.Add(new SeriesPoint("Australia", 7.68685)); series1.Points.Add(new SeriesPoint("India", 3.28759)); series1.Points.Add(new SeriesPoint("Others", 81.2)); // Add the series to the chart. DoughnutChart3D.Series.Add(series1); // Adjust the value numeric options of the series. series1.PointOptions.ValueNumericOptions.Format = NumericFormat.Percent; series1.PointOptions.ValueNumericOptions.Precision = 2; // Adjust the view-type-specific options of the series. ((Doughnut3DSeriesView)series1.View).HoleRadiusPercent = 30; ((Doughnut3DSeriesView)series1.View).ExplodedPoints.Add(series1.Points[0]); // Access the diagram's options. ((SimpleDiagram3D)DoughnutChart3D.Diagram).RotationType = RotationType.UseAngles; ((SimpleDiagram3D)DoughnutChart3D.Diagram).RotationAngleX = -35; // Add a title to the chart and hide the legend. ChartTitle chartTitle1 = new ChartTitle(); chartTitle1.Text = "3D Doughnut Chart"; DoughnutChart3D.Titles.Add(chartTitle1); DoughnutChart3D.Legend.Visible = false; // Add the chart to the form. DoughnutChart3D.Dock = DockStyle.Fill; this.Controls.Add(DoughnutChart3D); }

C#

复制代码

using System;
using System.Windows.Forms;
using DevExpress.XtraCharts;
// ...

private void Form1_Load(object sender, EventArgs e) {
    // Create an empty chart.
    ChartControl DoughnutChart3D = new ChartControl();

    // Create a doughnut series.
    Series series1 = new Series("Doughnut Series 1", ViewType.Doughnut3D);

    // Populate the series with points.
    series1.Points.Add(new SeriesPoint("Russia", 17.0752));
    series1.Points.Add(new SeriesPoint("Canada", 9.98467));
    series1.Points.Add(new SeriesPoint("USA", 9.63142));
    series1.Points.Add(new SeriesPoint("China", 9.59696));
    series1.Points.Add(new SeriesPoint("Brazil", 8.511965));
    series1.Points.Add(new SeriesPoint("Australia", 7.68685));
    series1.Points.Add(new SeriesPoint("India", 3.28759));
    series1.Points.Add(new SeriesPoint("Others", 81.2));

    // Add the series to the chart.
    DoughnutChart3D.Series.Add(series1);

    // Adjust the value numeric options of the series.
    series1.PointOptions.ValueNumericOptions.Format = NumericFormat.Percent;
    series1.PointOptions.ValueNumericOptions.Precision = 2;

    // Adjust the view-type-specific options of the series.
    ((Doughnut3DSeriesView)series1.View).HoleRadiusPercent = 30;
    ((Doughnut3DSeriesView)series1.View).ExplodedPoints.Add(series1.Points[0]);

    // Access the diagram's options.
    ((SimpleDiagram3D)DoughnutChart3D.Diagram).RotationType = RotationType.UseAngles;
    ((SimpleDiagram3D)DoughnutChart3D.Diagram).RotationAngleX = -35;

    // Add a title to the chart and hide the legend.
    ChartTitle chartTitle1 = new ChartTitle();
    chartTitle1.Text = "3D Doughnut Chart";
    DoughnutChart3D.Titles.Add(chartTitle1);
    DoughnutChart3D.Legend.Visible = false;

    // Add the chart to the form.
    DoughnutChart3D.Dock = DockStyle.Fill;
    this.Controls.Add(DoughnutChart3D);
}

Visual Basic	复制代码
Imports System Imports System.Windows.Forms Imports DevExpress.XtraCharts ' ... Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load ' Create an empty chart. Dim DoughnutChart3D As New ChartControl() ' Create a doughnut series. Dim series1 As New Series("Doughnut Series 1", ViewType.Doughnut3D) ' Populate the series with points. series1.Points.Add(New SeriesPoint("Russia", 17.0752)) series1.Points.Add(New SeriesPoint("Canada", 9.98467)) series1.Points.Add(New SeriesPoint("USA", 9.63142)) series1.Points.Add(New SeriesPoint("China", 9.59696)) series1.Points.Add(New SeriesPoint("Brazil", 8.511965)) series1.Points.Add(New SeriesPoint("Australia", 7.68685)) series1.Points.Add(New SeriesPoint("India", 3.28759)) series1.Points.Add(New SeriesPoint("Others", 81.2)) ' Add the series to the chart. DoughnutChart3D.Series.Add(series1) ' Adjust the value numeric options of the series. series1.PointOptions.ValueNumericOptions.Format = NumericFormat.Percent series1.PointOptions.ValueNumericOptions.Precision = 2 ' Adjust the view-type-specific options of the series. CType(series1.View, Doughnut3DSeriesView).HoleRadiusPercent = 30 CType(series1.View, Doughnut3DSeriesView).ExplodedPoints.Add(series1.Points(0)) ' Access the diagram's options. CType(DoughnutChart3D.Diagram, SimpleDiagram3D).RotationType = RotationType.UseAngles CType(DoughnutChart3D.Diagram, SimpleDiagram3D).RotationAngleX = -35 ' Add a title to the chart and hide the legend. Dim chartTitle1 As New ChartTitle() chartTitle1.Text = "3D Doughnut Chart" DoughnutChart3D.Titles.Add(chartTitle1) DoughnutChart3D.Legend.Visible = False ' Add the chart to the form. DoughnutChart3D.Dock = DockStyle.Fill Me.Controls.Add(DoughnutChart3D) End Sub

Visual Basic

复制代码

Imports System
Imports System.Windows.Forms
Imports DevExpress.XtraCharts
' ...

Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load
    ' Create an empty chart.
    Dim DoughnutChart3D As New ChartControl()

    ' Create a doughnut series.
    Dim series1 As New Series("Doughnut Series 1", ViewType.Doughnut3D)

    ' Populate the series with points.
    series1.Points.Add(New SeriesPoint("Russia", 17.0752))
    series1.Points.Add(New SeriesPoint("Canada", 9.98467))
    series1.Points.Add(New SeriesPoint("USA", 9.63142))
    series1.Points.Add(New SeriesPoint("China", 9.59696))
    series1.Points.Add(New SeriesPoint("Brazil", 8.511965))
    series1.Points.Add(New SeriesPoint("Australia", 7.68685))
    series1.Points.Add(New SeriesPoint("India", 3.28759))
    series1.Points.Add(New SeriesPoint("Others", 81.2))

    ' Add the series to the chart.
    DoughnutChart3D.Series.Add(series1)

    ' Adjust the value numeric options of the series.
    series1.PointOptions.ValueNumericOptions.Format = NumericFormat.Percent
    series1.PointOptions.ValueNumericOptions.Precision = 2

    ' Adjust the view-type-specific options of the series.
    CType(series1.View, Doughnut3DSeriesView).HoleRadiusPercent = 30
    CType(series1.View, Doughnut3DSeriesView).ExplodedPoints.Add(series1.Points(0))

    ' Access the diagram's options.
    CType(DoughnutChart3D.Diagram, SimpleDiagram3D).RotationType = RotationType.UseAngles
    CType(DoughnutChart3D.Diagram, SimpleDiagram3D).RotationAngleX = -35

    ' Add a title to the chart and hide the legend.
    Dim chartTitle1 As New ChartTitle()
    chartTitle1.Text = "3D Doughnut Chart"
    DoughnutChart3D.Titles.Add(chartTitle1)
    DoughnutChart3D.Legend.Visible = False

    ' Add the chart to the form.
    DoughnutChart3D.Dock = DockStyle.Fill
    Me.Controls.Add(DoughnutChart3D)
End Sub

Show Me
在 DevExpress Code Central 数据库中可以找到完整的示例项目，网址是 http://www.devexpress.com/example=E1020。取决于目标平台类型 (ASP.NET、WinForms 等)，可以在线运行本示例，或者下载自动可执行的示例。

简单的三维图象

简要说明

图表类型特征

示例

参阅