极坐标面积图

极坐标面积图 是由 PolarAreaSeriesView 对象来表示的，此对象属于极坐标系列视图。当需要以角度为基础把系列显示为圆形图象上的填充面积时，这种视图是有用的。注意，尽管这些图表通常都有一个圆形形状，但是也可以被显示为多边形。这是通过 RadarDiagram.DrawingStyle 属性进行控制的。

在下面的插图中显示了一个极坐标面积图。

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	PolarAreaSeriesView
图象类型	PolarDiagram
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极坐标面积图组合使用的信息，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 PolarAreaSeriesView 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 a new chart. ChartControl polarAreaChart = new ChartControl(); // Add a polar series to it. Series series1 = new Series("Series 1", ViewType.PolarArea); // Populate the series with points. series1.Points.Add(new SeriesPoint(0, 90)); series1.Points.Add(new SeriesPoint(90, 70)); series1.Points.Add(new SeriesPoint(180, 50)); series1.Points.Add(new SeriesPoint(270, 100)); // Add the series to the chart. polarAreaChart.Series.Add(series1); // Adjust the series options. series1.Label.Visible = false; // Flip the diagram (if necessary). ((PolarDiagram)polarAreaChart.Diagram).StartAngleInDegrees = 180; ((PolarDiagram)polarAreaChart.Diagram).RotationDirection = RadarDiagramRotationDirection.Counterclockwise; // Add a title to the chart and hide the legend. ChartTitle chartTitle1 = new ChartTitle(); chartTitle1.Text = "Polar Area Chart"; polarAreaChart.Titles.Add(chartTitle1); polarAreaChart.Legend.Visible = false; // Add the chart to the form. polarAreaChart.Dock = DockStyle.Fill; this.Controls.Add(polarAreaChart); }

C#

复制代码

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

private void Form1_Load(object sender, EventArgs e) {
    // Create a new chart.
    ChartControl polarAreaChart = new ChartControl();

    // Add a polar series to it.
    Series series1 = new Series("Series 1", ViewType.PolarArea);

    // Populate the series with points.
    series1.Points.Add(new SeriesPoint(0, 90));
    series1.Points.Add(new SeriesPoint(90, 70));
    series1.Points.Add(new SeriesPoint(180, 50));
    series1.Points.Add(new SeriesPoint(270, 100));

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

    // Adjust the series options.
    series1.Label.Visible = false;

    // Flip the diagram (if necessary).
    ((PolarDiagram)polarAreaChart.Diagram).StartAngleInDegrees = 180;
    ((PolarDiagram)polarAreaChart.Diagram).RotationDirection = 
        RadarDiagramRotationDirection.Counterclockwise;

    // Add a title to the chart and hide the legend.
    ChartTitle chartTitle1 = new ChartTitle();
    chartTitle1.Text = "Polar Area Chart";
    polarAreaChart.Titles.Add(chartTitle1);
    polarAreaChart.Legend.Visible = false;

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

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 a new chart. Dim polarAreaChart As New ChartControl() ' Add a polar series to it. Dim series1 As New Series("Series 1", ViewType.PolarArea) ' Populate the series with points. series1.Points.Add(New SeriesPoint(0, 90)) series1.Points.Add(New SeriesPoint(90, 70)) series1.Points.Add(New SeriesPoint(180, 50)) series1.Points.Add(New SeriesPoint(270, 100)) ' Add the series to the chart. polarAreaChart.Series.Add(series1) ' Adjust the series options. series1.Label.Visible = False ' Flip the diagram (if necessary). CType(polarAreaChart.Diagram, PolarDiagram).StartAngleInDegrees = 180 CType(polarAreaChart.Diagram, PolarDiagram).RotationDirection = _ RadarDiagramRotationDirection.Counterclockwise ' Add a title to the chart and hide the legend. Dim chartTitle1 As New ChartTitle() chartTitle1.Text = "Polar Area Chart" polarAreaChart.Titles.Add(chartTitle1) polarAreaChart.Legend.Visible = False ' Add the chart to the form. polarAreaChart.Dock = DockStyle.Fill Me.Controls.Add(polarAreaChart) 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 a new chart.
    Dim polarAreaChart As New ChartControl()

    ' Add a polar series to it.
    Dim series1 As New Series("Series 1", ViewType.PolarArea)

    ' Populate the series with points.
    series1.Points.Add(New SeriesPoint(0, 90))
    series1.Points.Add(New SeriesPoint(90, 70))
    series1.Points.Add(New SeriesPoint(180, 50))
    series1.Points.Add(New SeriesPoint(270, 100))

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

    ' Adjust the series options.
    series1.Label.Visible = False

    ' Flip the diagram (if necessary).
    CType(polarAreaChart.Diagram, PolarDiagram).StartAngleInDegrees = 180
    CType(polarAreaChart.Diagram, PolarDiagram).RotationDirection = _ 
RadarDiagramRotationDirection.Counterclockwise

    ' Add a title to the chart and hide the legend.
    Dim chartTitle1 As New ChartTitle()
    chartTitle1.Text = "Polar Area Chart"
    polarAreaChart.Titles.Add(chartTitle1)
    polarAreaChart.Legend.Visible = False

    ' Add the chart to the form.
    polarAreaChart.Dock = DockStyle.Fill
    Me.Controls.Add(polarAreaChart)
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=E1055。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。

雷达图象和极坐标图象

简要说明

图表类型特征

示例

参阅