ChartDirector 6.2 (.NET Edition)

Neon Round Meters


      

This examples demonstrates various shading effects to create round meters with a neon look and feel. It also demonstrates how to create meters that can easily be resized.

In this example, the code uses a single size parameter as input, and it derives all the other sizes, such as the radius of the various parts of the chart, the font size, line widths and tick lengths. This allows the chart to be easily resized by changing only one parameter.

For the colors, apart from black and white, the code only uses a single color as input. BaseChart.adjustBrightness is used to create brighter or darker versions of that color, and AngularMeter.relativeRadialGradient is used to combine them in gradients.

Source Code Listing

[Windows Forms - C# version] NetWinCharts\CSharpWinCharts\neonroundmeter.cs
using System;
using ChartDirector;

namespace CSharpChartExplorer
{
    public class neonroundmeter : DemoModule
    {
        //Name of demo module
        public string getName() { return "Neon Round Meters"; }

        //Number of charts produced in this demo module
        public int getNoOfCharts() { return 4; }

        //Main code for creating charts
        public void createChart(WinChartViewer viewer, int chartIndex)
        {
            // The value to display on the meter
            double value = 50;

            // The main color of the four meters in this example. The other colors and gradients are
            // derived from the main color.
            int[] colorList = {0x007700, 0x770077, 0x0033dd, 0x880000};
            int mainColor = colorList[chartIndex];

            //
            // In this example, we demonstrate how to parameterized by size, so that the chart size
            // can be changed by changing just one variable.
            //
            int size = 300;

            // The radius of the entire meter, which is size / 2, minus 2 pixels for margin
            int outerRadius = size / 2 - 2;

            // The radius of the meter scale
            int scaleRadius = outerRadius * 92 / 100;

            // The radius of the inner decorative circle
            int innerRadius = scaleRadius * 40 / 100;

            // The width of the color scale
            int colorScaleWidth = scaleRadius * 10 / 100;

            // Major tick length
            int tickLength = scaleRadius * 10 / 100;

            // Major tick width
            int tickWidth = scaleRadius * 1 / 100 + 1;

            // Label font size
            int fontSize = scaleRadius * 13 / 100;

            //
            // Create an angular meter based on the above parameters
            //

            // Create an AngularMeter object of the specified size. In this demo, we use black
            // (0x000000) as the background color. You can also use transparent or other colors.
            AngularMeter m = new AngularMeter(size, size, 0x000000);

            // Set the default text and line colors to white (0xffffff)
            m.setColor(Chart.TextColor, 0xffffff);
            m.setColor(Chart.LineColor, 0xffffff);

            // Set meter center and scale radius, and set the scale angle from -180 to +90 degrees
            m.setMeter(size / 2, size / 2, scaleRadius, -180, 90);

            // Background gradient with the mainColor at the center and become darker near the
            // border
            double[] bgGradient = {0, mainColor, 0.5, m.adjustBrightness(mainColor, 0.75), 1,
                m.adjustBrightness(mainColor, 0.15)};

            // Fill the meter background with the background gradient
            m.addRing(0, outerRadius, m.relativeRadialGradient(bgGradient, outerRadius * 0.66));

            // Fill the inner circle with the same background gradient for decoration
            m.addRing(0, innerRadius, m.relativeRadialGradient(bgGradient, innerRadius * 0.8));

            // Gradient for the neon backlight, with the main color at the scale radius fading to
            // transparent
            double[] neonGradient = {0.89, Chart.Transparent, 1, mainColor, 1.07, Chart.Transparent}
                ;
            m.addRing(scaleRadius * 85 / 100, outerRadius, m.relativeRadialGradient(neonGradient));

            // The neon ring at the scale radius with width equal to 1/80 of the scale radius,
            // creating using a brighter version of the main color
            m.addRing(scaleRadius, scaleRadius + scaleRadius / 80, m.adjustBrightness(mainColor, 2))
                ;

            // Meter scale is 0 - 100, with major/minor/micro ticks every 10/5/1 units
            m.setScale(0, 100, 10, 5, 1);

            // Set the scale label style, tick length and tick width. The minor and micro tick
            // lengths are 80% and 60% of the major tick length, and their widths are around half of
            // the major tick width.
            m.setLabelStyle("Arial Italic", fontSize);
            m.setTickLength(-tickLength, -tickLength * 80 / 100, -tickLength * 60 / 100);
            m.setLineWidth(0, tickWidth, tickWidth + 1 / 2, tickWidth + 1 / 2);

            // Demostrate different types of color scales and glare effects and putting them at
            // different positions.
            double[] smoothColorScale = {0, 0x0000ff, 25, 0x0088ff, 50, 0x00ff00, 75, 0xdddd00, 100,
                0xff0000};
            double[] stepColorScale = {0, 0x00dd00, 60, 0xddaa00, 80, 0xdd0000, 100};
            double[] highColorScale = {70, Chart.Transparent, 100, 0xff0000};

            if (chartIndex == 1) {
                // Add the smooth color scale just outside the inner circle
                m.addColorScale(smoothColorScale, innerRadius + 1, colorScaleWidth);
                // Add glare up to the scale radius, concave and spanning 190 degrees
                m.addGlare(scaleRadius, -190);
            } else if (chartIndex == 2) {
                // Add the high color scale at the default position
                m.addColorScale(highColorScale);
                // Add glare up to the scale radius
                m.addGlare(scaleRadius);
            } else {
                // Add the step color scale just outside the inner circle
                m.addColorScale(stepColorScale, innerRadius + 1, colorScaleWidth);
                // Add glare up to the scale radius, concave and spanning 190 degrees and rotated by
                // -45 degrees
                m.addGlare(scaleRadius, -190, -45);
            }

            // Add a red (0xff0000) pointer at the specified value
            m.addPointer2(value, 0xff0000);

            // Set the cap background to a brighter version of the mainColor, and using black
            // (0x000000) for the cap and grey (0x999999) for the cap border
            m.setCap2(m.adjustBrightness(mainColor, 1.1), 0x000000, 0x999999);

            // Output the chart
            viewer.Chart = m;
        }
    }
}

[Windows Forms - VB Version] NetWinCharts\VBNetWinCharts\neonroundmeter.vb
Imports System
Imports Microsoft.VisualBasic
Imports ChartDirector

Public Class neonroundmeter
    Implements DemoModule

    'Name of demo module
    Public Function getName() As String Implements DemoModule.getName
        Return "Neon Round Meters"
    End Function

    'Number of charts produced in this demo module
    Public Function getNoOfCharts() As Integer Implements DemoModule.getNoOfCharts
        Return 4
    End Function

    'Main code for creating charts
    Public Sub createChart(viewer As WinChartViewer, chartIndex As Integer) _
        Implements DemoModule.createChart

        ' The value to display on the meter
        Dim value As Double = 50

        ' The main color of the four meters in this example. The other colors and gradients are
        ' derived from the main color.
        Dim colorList() As Integer = {&H007700, &H770077, &H0033dd, &H880000}
        Dim mainColor As Integer = colorList(chartIndex)

        '
        ' In this example, we demonstrate how to parameterized by size, so that the chart size can
        ' be changed by changing just one variable.
        '
        Dim size As Integer = 300

        ' The radius of the entire meter, which is size / 2, minus 2 pixels for margin
        Dim outerRadius As Integer = Int(size / 2 - 2)

        ' The radius of the meter scale
        Dim scaleRadius As Integer = Int(outerRadius * 92 / 100)

        ' The radius of the inner decorative circle
        Dim innerRadius As Integer = Int(scaleRadius * 40 / 100)

        ' The width of the color scale
        Dim colorScaleWidth As Integer = Int(scaleRadius * 10 / 100)

        ' Major tick length
        Dim tickLength As Integer = Int(scaleRadius * 10 / 100)

        ' Major tick width
        Dim tickWidth As Integer = Int(scaleRadius * 1 / 100 + 1)

        ' Label font size
        Dim fontSize As Integer = Int(scaleRadius * 13 / 100)

        '
        ' Create an angular meter based on the above parameters
        '

        ' Create an AngularMeter object of the specified size. In this demo, we use black (0x000000)
        ' as the background color. You can also use transparent or other colors.
        Dim m As AngularMeter = New AngularMeter(size, size, &H000000)

        ' Set the default text and line colors to white (0xffffff)
        m.setColor(Chart.TextColor, &Hffffff)
        m.setColor(Chart.LineColor, &Hffffff)

        ' Set meter center and scale radius, and set the scale angle from -180 to +90 degrees
        m.setMeter(size / 2, size / 2, scaleRadius, -180, 90)

        ' Background gradient with the mainColor at the center and become darker near the border
        Dim bgGradient() As Double = {0, mainColor, 0.5, m.adjustBrightness(mainColor, 0.75), 1, _
            m.adjustBrightness(mainColor, 0.15)}

        ' Fill the meter background with the background gradient
        m.addRing(0, outerRadius, m.relativeRadialGradient(bgGradient, outerRadius * 0.66))

        ' Fill the inner circle with the same background gradient for decoration
        m.addRing(0, innerRadius, m.relativeRadialGradient(bgGradient, innerRadius * 0.8))

        ' Gradient for the neon backlight, with the main color at the scale radius fading to
        ' transparent
        Dim neonGradient() As Double = {0.89, Chart.Transparent, 1, mainColor, 1.07, _
            Chart.Transparent}
        m.addRing(Int(scaleRadius * 85 / 100), outerRadius, m.relativeRadialGradient(neonGradient))

        ' The neon ring at the scale radius with width equal to 1/80 of the scale radius, creating
        ' using a brighter version of the main color
        m.addRing(scaleRadius, Int(scaleRadius + scaleRadius / 80), m.adjustBrightness(mainColor, _
            2))

        ' Meter scale is 0 - 100, with major/minor/micro ticks every 10/5/1 units
        m.setScale(0, 100, 10, 5, 1)

        ' Set the scale label style, tick length and tick width. The minor and micro tick lengths
        ' are 80% and 60% of the major tick length, and their widths are around half of the major
        ' tick width.
        m.setLabelStyle("Arial Italic", fontSize)
        m.setTickLength(-tickLength, -Int(tickLength * 80 / 100), -Int(tickLength * 60 / 100))
        m.setLineWidth(0, tickWidth, Int(tickWidth + 1 / 2), Int(tickWidth + 1 / 2))

        ' Demostrate different types of color scales and glare effects and putting them at different
        ' positions.
        Dim smoothColorScale() As Double = {0, &H0000ff, 25, &H0088ff, 50, &H00ff00, 75, &Hdddd00, _
            100, &Hff0000}
        Dim stepColorScale() As Double = {0, &H00dd00, 60, &Hddaa00, 80, &Hdd0000, 100}
        Dim highColorScale() As Double = {70, Chart.Transparent, 100, &Hff0000}

        If chartIndex = 1 Then
            ' Add the smooth color scale just outside the inner circle
            m.addColorScale(smoothColorScale, innerRadius + 1, colorScaleWidth)
            ' Add glare up to the scale radius, concave and spanning 190 degrees
            m.addGlare(scaleRadius, -190)
        ElseIf chartIndex = 2 Then
            ' Add the high color scale at the default position
            m.addColorScale(highColorScale)
            ' Add glare up to the scale radius
            m.addGlare(scaleRadius)
        Else
            ' Add the step color scale just outside the inner circle
            m.addColorScale(stepColorScale, innerRadius + 1, colorScaleWidth)
            ' Add glare up to the scale radius, concave and spanning 190 degrees and rotated by -45
            ' degrees
            m.addGlare(scaleRadius, -190, -45)
        End If

        ' Add a red (0xff0000) pointer at the specified value
        m.addPointer2(value, &Hff0000)

        ' Set the cap background to a brighter version of the mainColor, and using black (0x000000)
        ' for the cap and grey (0x999999) for the cap border
        m.setCap2(m.adjustBrightness(mainColor, 1.1), &H000000, &H999999)

        ' Output the chart
        viewer.Chart = m

    End Sub

End Class

[WPF - C#] NetWPFCharts\neonroundmeter.cs
using System;
using ChartDirector;

namespace CSharpWPFDemo
{
    public class neonroundmeter : DemoModule
    {
        //Name of demo module
        public string getName() { return "Neon Round Meters"; }

        //Number of charts produced in this demo module
        public int getNoOfCharts() { return 4; }

        //Main code for creating charts
        public void createChart(WPFChartViewer viewer, int chartIndex)
        {
            // The value to display on the meter
            double value = 50;

            // The main color of the four meters in this example. The other colors and gradients are
            // derived from the main color.
            int[] colorList = {0x007700, 0x770077, 0x0033dd, 0x880000};
            int mainColor = colorList[chartIndex];

            //
            // In this example, we demonstrate how to parameterized by size, so that the chart size
            // can be changed by changing just one variable.
            //
            int size = 300;

            // The radius of the entire meter, which is size / 2, minus 2 pixels for margin
            int outerRadius = size / 2 - 2;

            // The radius of the meter scale
            int scaleRadius = outerRadius * 92 / 100;

            // The radius of the inner decorative circle
            int innerRadius = scaleRadius * 40 / 100;

            // The width of the color scale
            int colorScaleWidth = scaleRadius * 10 / 100;

            // Major tick length
            int tickLength = scaleRadius * 10 / 100;

            // Major tick width
            int tickWidth = scaleRadius * 1 / 100 + 1;

            // Label font size
            int fontSize = scaleRadius * 13 / 100;

            //
            // Create an angular meter based on the above parameters
            //

            // Create an AngularMeter object of the specified size. In this demo, we use black
            // (0x000000) as the background color. You can also use transparent or other colors.
            AngularMeter m = new AngularMeter(size, size, 0x000000);

            // Set the default text and line colors to white (0xffffff)
            m.setColor(Chart.TextColor, 0xffffff);
            m.setColor(Chart.LineColor, 0xffffff);

            // Set meter center and scale radius, and set the scale angle from -180 to +90 degrees
            m.setMeter(size / 2, size / 2, scaleRadius, -180, 90);

            // Background gradient with the mainColor at the center and become darker near the
            // border
            double[] bgGradient = {0, mainColor, 0.5, m.adjustBrightness(mainColor, 0.75), 1,
                m.adjustBrightness(mainColor, 0.15)};

            // Fill the meter background with the background gradient
            m.addRing(0, outerRadius, m.relativeRadialGradient(bgGradient, outerRadius * 0.66));

            // Fill the inner circle with the same background gradient for decoration
            m.addRing(0, innerRadius, m.relativeRadialGradient(bgGradient, innerRadius * 0.8));

            // Gradient for the neon backlight, with the main color at the scale radius fading to
            // transparent
            double[] neonGradient = {0.89, Chart.Transparent, 1, mainColor, 1.07, Chart.Transparent}
                ;
            m.addRing(scaleRadius * 85 / 100, outerRadius, m.relativeRadialGradient(neonGradient));

            // The neon ring at the scale radius with width equal to 1/80 of the scale radius,
            // creating using a brighter version of the main color
            m.addRing(scaleRadius, scaleRadius + scaleRadius / 80, m.adjustBrightness(mainColor, 2))
                ;

            // Meter scale is 0 - 100, with major/minor/micro ticks every 10/5/1 units
            m.setScale(0, 100, 10, 5, 1);

            // Set the scale label style, tick length and tick width. The minor and micro tick
            // lengths are 80% and 60% of the major tick length, and their widths are around half of
            // the major tick width.
            m.setLabelStyle("Arial Italic", fontSize);
            m.setTickLength(-tickLength, -tickLength * 80 / 100, -tickLength * 60 / 100);
            m.setLineWidth(0, tickWidth, (tickWidth + 1) / 2, (tickWidth + 1) / 2);

            // Demostrate different types of color scales and glare effects and putting them at
            // different positions.
            double[] smoothColorScale = {0, 0x0000ff, 25, 0x0088ff, 50, 0x00ff00, 75, 0xdddd00, 100,
                0xff0000};
            double[] stepColorScale = {0, 0x00dd00, 60, 0xddaa00, 80, 0xdd0000, 100};
            double[] highColorScale = {70, Chart.Transparent, 100, 0xff0000};

            if (chartIndex == 1) {
                // Add the smooth color scale just outside the inner circle
                m.addColorScale(smoothColorScale, innerRadius + 1, colorScaleWidth);
                // Add glare up to the scale radius, concave and spanning 190 degrees
                m.addGlare(scaleRadius, -190);
            } else if (chartIndex == 2) {
                // Add the high color scale at the default position
                m.addColorScale(highColorScale);
                // Add glare up to the scale radius
                m.addGlare(scaleRadius);
            } else {
                // Add the step color scale just outside the inner circle
                m.addColorScale(stepColorScale, innerRadius + 1, colorScaleWidth);
                // Add glare up to the scale radius, concave and spanning 190 degrees and rotated by
                // -45 degrees
                m.addGlare(scaleRadius, -190, -45);
            }

            // Add a red (0xff0000) pointer at the specified value
            m.addPointer2(value, 0xff0000);

            // Set the cap background to a brighter version of the mainColor, and using black
            // (0x000000) for the cap and grey (0x999999) for the cap border
            m.setCap2(m.adjustBrightness(mainColor, 1.1), 0x000000, 0x999999);

            // Output the chart
            viewer.Chart = m;
        }
    }
}

[ASP.NET Web Forms - C# version] NetWebCharts\CSharpASP\neonroundmeter.aspx
(Click here on how to convert this code to code-behind style.)
<%@ Page Language="C#" Debug="true" %>
<%@ Import Namespace="ChartDirector" %>
<%@ Register TagPrefix="chart" Namespace="ChartDirector" Assembly="netchartdir" %>

<!DOCTYPE html>

<script runat="server">

//
// Create chart
//
protected void createChart(WebChartViewer viewer, int chartIndex)
{
    // The value to display on the meter
    double value = 50;

    // The main color of the four meters in this example. The other colors and gradients are derived
    // from the main color.
    int[] colorList = {0x007700, 0x770077, 0x0033dd, 0x880000};
    int mainColor = colorList[chartIndex];

    //
    // In this example, we demonstrate how to parameterized by size, so that the chart size can be
    // changed by changing just one variable.
    //
    int size = 300;

    // The radius of the entire meter, which is size / 2, minus 2 pixels for margin
    int outerRadius = size / 2 - 2;

    // The radius of the meter scale
    int scaleRadius = outerRadius * 92 / 100;

    // The radius of the inner decorative circle
    int innerRadius = scaleRadius * 40 / 100;

    // The width of the color scale
    int colorScaleWidth = scaleRadius * 10 / 100;

    // Major tick length
    int tickLength = scaleRadius * 10 / 100;

    // Major tick width
    int tickWidth = scaleRadius * 1 / 100 + 1;

    // Label font size
    int fontSize = scaleRadius * 13 / 100;

    //
    // Create an angular meter based on the above parameters
    //

    // Create an AngularMeter object of the specified size. In this demo, we use black (0x000000) as
    // the background color. You can also use transparent or other colors.
    AngularMeter m = new AngularMeter(size, size, 0x000000);

    // Set the default text and line colors to white (0xffffff)
    m.setColor(Chart.TextColor, 0xffffff);
    m.setColor(Chart.LineColor, 0xffffff);

    // Set meter center and scale radius, and set the scale angle from -180 to +90 degrees
    m.setMeter(size / 2, size / 2, scaleRadius, -180, 90);

    // Background gradient with the mainColor at the center and become darker near the border
    double[] bgGradient = {0, mainColor, 0.5, m.adjustBrightness(mainColor, 0.75), 1,
        m.adjustBrightness(mainColor, 0.15)};

    // Fill the meter background with the background gradient
    m.addRing(0, outerRadius, m.relativeRadialGradient(bgGradient, outerRadius * 0.66));

    // Fill the inner circle with the same background gradient for decoration
    m.addRing(0, innerRadius, m.relativeRadialGradient(bgGradient, innerRadius * 0.8));

    // Gradient for the neon backlight, with the main color at the scale radius fading to
    // transparent
    double[] neonGradient = {0.89, Chart.Transparent, 1, mainColor, 1.07, Chart.Transparent};
    m.addRing(scaleRadius * 85 / 100, outerRadius, m.relativeRadialGradient(neonGradient));

    // The neon ring at the scale radius with width equal to 1/80 of the scale radius, creating
    // using a brighter version of the main color
    m.addRing(scaleRadius, scaleRadius + scaleRadius / 80, m.adjustBrightness(mainColor, 2));

    // Meter scale is 0 - 100, with major/minor/micro ticks every 10/5/1 units
    m.setScale(0, 100, 10, 5, 1);

    // Set the scale label style, tick length and tick width. The minor and micro tick lengths are
    // 80% and 60% of the major tick length, and their widths are around half of the major tick
    // width.
    m.setLabelStyle("Arial Italic", fontSize);
    m.setTickLength(-tickLength, -tickLength * 80 / 100, -tickLength * 60 / 100);
    m.setLineWidth(0, tickWidth, (tickWidth + 1) / 2, (tickWidth + 1) / 2);

    // Demostrate different types of color scales and glare effects and putting them at different
    // positions.
    double[] smoothColorScale = {0, 0x0000ff, 25, 0x0088ff, 50, 0x00ff00, 75, 0xdddd00, 100,
        0xff0000};
    double[] stepColorScale = {0, 0x00dd00, 60, 0xddaa00, 80, 0xdd0000, 100};
    double[] highColorScale = {70, Chart.Transparent, 100, 0xff0000};

    if (chartIndex == 1) {
        // Add the smooth color scale just outside the inner circle
        m.addColorScale(smoothColorScale, innerRadius + 1, colorScaleWidth);
        // Add glare up to the scale radius, concave and spanning 190 degrees
        m.addGlare(scaleRadius, -190);
    } else if (chartIndex == 2) {
        // Add the high color scale at the default position
        m.addColorScale(highColorScale);
        // Add glare up to the scale radius
        m.addGlare(scaleRadius);
    } else {
        // Add the step color scale just outside the inner circle
        m.addColorScale(stepColorScale, innerRadius + 1, colorScaleWidth);
        // Add glare up to the scale radius, concave and spanning 190 degrees and rotated by -45
        // degrees
        m.addGlare(scaleRadius, -190, -45);
    }

    // Add a red (0xff0000) pointer at the specified value
    m.addPointer2(value, 0xff0000);

    // Set the cap background to a brighter version of the mainColor, and using black (0x000000) for
    // the cap and grey (0x999999) for the cap border
    m.setCap2(m.adjustBrightness(mainColor, 1.1), 0x000000, 0x999999);

    // Output the chart
    viewer.Image = m.makeWebImage(Chart.PNG);
}

//
// Page Load event handler
//
protected void Page_Load(object sender, EventArgs e)
{
    createChart(WebChartViewer0, 0);
    createChart(WebChartViewer1, 1);
    createChart(WebChartViewer2, 2);
    createChart(WebChartViewer3, 3);
}

</script>

<html>
<body>
    <chart:WebChartViewer id="WebChartViewer0" runat="server" />
    <chart:WebChartViewer id="WebChartViewer1" runat="server" />
    <chart:WebChartViewer id="WebChartViewer2" runat="server" />
    <chart:WebChartViewer id="WebChartViewer3" runat="server" />
</body>
</html>

[ASP.NET Web Forms - VB Version] NetWebCharts\VBNetASP\neonroundmeter.aspx
(Click here on how to convert this code to code-behind style.)
<%@ Page Language="VB" Debug="true" %>
<%@ Import Namespace="ChartDirector" %>
<%@ Register TagPrefix="chart" Namespace="ChartDirector" Assembly="netchartdir" %>

<!DOCTYPE html>

<script runat="server">

'
' Create chart
'
Protected Sub createChart(viewer As WebChartViewer, chartIndex As Integer)

    ' The value to display on the meter
    Dim value As Double = 50

    ' The main color of the four meters in this example. The other colors and gradients are derived
    ' from the main color.
    Dim colorList() As Integer = {&H007700, &H770077, &H0033dd, &H880000}
    Dim mainColor As Integer = colorList(chartIndex)

    '
    ' In this example, we demonstrate how to parameterized by size, so that the chart size can be
    ' changed by changing just one variable.
    '
    Dim size As Integer = 300

    ' The radius of the entire meter, which is size / 2, minus 2 pixels for margin
    Dim outerRadius As Integer = Int(size / 2 - 2)

    ' The radius of the meter scale
    Dim scaleRadius As Integer = Int(outerRadius * 92 / 100)

    ' The radius of the inner decorative circle
    Dim innerRadius As Integer = Int(scaleRadius * 40 / 100)

    ' The width of the color scale
    Dim colorScaleWidth As Integer = Int(scaleRadius * 10 / 100)

    ' Major tick length
    Dim tickLength As Integer = Int(scaleRadius * 10 / 100)

    ' Major tick width
    Dim tickWidth As Integer = Int(scaleRadius * 1 / 100 + 1)

    ' Label font size
    Dim fontSize As Integer = Int(scaleRadius * 13 / 100)

    '
    ' Create an angular meter based on the above parameters
    '

    ' Create an AngularMeter object of the specified size. In this demo, we use black (0x000000) as
    ' the background color. You can also use transparent or other colors.
    Dim m As AngularMeter = New AngularMeter(size, size, &H000000)

    ' Set the default text and line colors to white (0xffffff)
    m.setColor(Chart.TextColor, &Hffffff)
    m.setColor(Chart.LineColor, &Hffffff)

    ' Set meter center and scale radius, and set the scale angle from -180 to +90 degrees
    m.setMeter(size / 2, size / 2, scaleRadius, -180, 90)

    ' Background gradient with the mainColor at the center and become darker near the border
    Dim bgGradient() As Double = {0, mainColor, 0.5, m.adjustBrightness(mainColor, 0.75), 1, _
        m.adjustBrightness(mainColor, 0.15)}

    ' Fill the meter background with the background gradient
    m.addRing(0, outerRadius, m.relativeRadialGradient(bgGradient, outerRadius * 0.66))

    ' Fill the inner circle with the same background gradient for decoration
    m.addRing(0, innerRadius, m.relativeRadialGradient(bgGradient, innerRadius * 0.8))

    ' Gradient for the neon backlight, with the main color at the scale radius fading to transparent
    Dim neonGradient() As Double = {0.89, Chart.Transparent, 1, mainColor, 1.07, Chart.Transparent}
    m.addRing(Int(scaleRadius * 85 / 100), outerRadius, m.relativeRadialGradient(neonGradient))

    ' The neon ring at the scale radius with width equal to 1/80 of the scale radius, creating using
    ' a brighter version of the main color
    m.addRing(scaleRadius, Int(scaleRadius + scaleRadius / 80), m.adjustBrightness(mainColor, 2))

    ' Meter scale is 0 - 100, with major/minor/micro ticks every 10/5/1 units
    m.setScale(0, 100, 10, 5, 1)

    ' Set the scale label style, tick length and tick width. The minor and micro tick lengths are
    ' 80% and 60% of the major tick length, and their widths are around half of the major tick
    ' width.
    m.setLabelStyle("Arial Italic", fontSize)
    m.setTickLength(-tickLength, -Int(tickLength * 80 / 100), -Int(tickLength * 60 / 100))
    m.setLineWidth(0, tickWidth, Int((tickWidth + 1) / 2), Int((tickWidth + 1) / 2))

    ' Demostrate different types of color scales and glare effects and putting them at different
    ' positions.
    Dim smoothColorScale() As Double = {0, &H0000ff, 25, &H0088ff, 50, &H00ff00, 75, &Hdddd00, _
        100, &Hff0000}
    Dim stepColorScale() As Double = {0, &H00dd00, 60, &Hddaa00, 80, &Hdd0000, 100}
    Dim highColorScale() As Double = {70, Chart.Transparent, 100, &Hff0000}

    If chartIndex = 1 Then
        ' Add the smooth color scale just outside the inner circle
        m.addColorScale(smoothColorScale, innerRadius + 1, colorScaleWidth)
        ' Add glare up to the scale radius, concave and spanning 190 degrees
        m.addGlare(scaleRadius, -190)
    ElseIf chartIndex = 2 Then
        ' Add the high color scale at the default position
        m.addColorScale(highColorScale)
        ' Add glare up to the scale radius
        m.addGlare(scaleRadius)
    Else
        ' Add the step color scale just outside the inner circle
        m.addColorScale(stepColorScale, innerRadius + 1, colorScaleWidth)
        ' Add glare up to the scale radius, concave and spanning 190 degrees and rotated by -45
        ' degrees
        m.addGlare(scaleRadius, -190, -45)
    End If

    ' Add a red (0xff0000) pointer at the specified value
    m.addPointer2(value, &Hff0000)

    ' Set the cap background to a brighter version of the mainColor, and using black (0x000000) for
    ' the cap and grey (0x999999) for the cap border
    m.setCap2(m.adjustBrightness(mainColor, 1.1), &H000000, &H999999)

    ' Output the chart
    viewer.Image = m.makeWebImage(Chart.PNG)

End Sub

'
' Page Load event handler
'
Protected Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs)

    createChart(WebChartViewer0, 0)
    createChart(WebChartViewer1, 1)
    createChart(WebChartViewer2, 2)
    createChart(WebChartViewer3, 3)

End Sub

</script>

<html>
<body>
    <chart:WebChartViewer id="WebChartViewer0" runat="server" />
    <chart:WebChartViewer id="WebChartViewer1" runat="server" />
    <chart:WebChartViewer id="WebChartViewer2" runat="server" />
    <chart:WebChartViewer id="WebChartViewer3" runat="server" />
</body>
</html>

[ASP.NET MVC - Controller] NetMvcCharts\Controllers\NeonroundmeterController.cs
using System;
using System.Web.Mvc;
using ChartDirector;

namespace NetMvcCharts.Controllers
{
    public class NeonroundmeterController : Controller
    {
        //
        // Default Action
        //
        public ActionResult Index()
        {
            ViewBag.Title = "Neon Round Meters";

            // This example contains 4 charts.
            ViewBag.Viewer = new RazorChartViewer[4];
            for (int i = 0; i < ViewBag.Viewer.Length; ++i)
                createChart(ViewBag.Viewer[i] = new RazorChartViewer(HttpContext, "chart" + i), i);

            return View("~/Views/Shared/ChartView.cshtml");
        }

        //
        // Create chart
        //
        private void createChart(RazorChartViewer viewer, int chartIndex)
        {
            // The value to display on the meter
            double value = 50;

            // The main color of the four meters in this example. The other colors and gradients are
            // derived from the main color.
            int[] colorList = {0x007700, 0x770077, 0x0033dd, 0x880000};
            int mainColor = colorList[chartIndex];

            //
            // In this example, we demonstrate how to parameterized by size, so that the chart size can
            // be changed by changing just one variable.
            //
            int size = 300;

            // The radius of the entire meter, which is size / 2, minus 2 pixels for margin
            int outerRadius = size / 2 - 2;

            // The radius of the meter scale
            int scaleRadius = outerRadius * 92 / 100;

            // The radius of the inner decorative circle
            int innerRadius = scaleRadius * 40 / 100;

            // The width of the color scale
            int colorScaleWidth = scaleRadius * 10 / 100;

            // Major tick length
            int tickLength = scaleRadius * 10 / 100;

            // Major tick width
            int tickWidth = scaleRadius * 1 / 100 + 1;

            // Label font size
            int fontSize = scaleRadius * 13 / 100;

            //
            // Create an angular meter based on the above parameters
            //

            // Create an AngularMeter object of the specified size. In this demo, we use black (0x000000)
            // as the background color. You can also use transparent or other colors.
            AngularMeter m = new AngularMeter(size, size, 0x000000);

            // Set the default text and line colors to white (0xffffff)
            m.setColor(Chart.TextColor, 0xffffff);
            m.setColor(Chart.LineColor, 0xffffff);

            // Set meter center and scale radius, and set the scale angle from -180 to +90 degrees
            m.setMeter(size / 2, size / 2, scaleRadius, -180, 90);

            // Background gradient with the mainColor at the center and become darker near the border
            double[] bgGradient = {0, mainColor, 0.5, m.adjustBrightness(mainColor, 0.75), 1,
                m.adjustBrightness(mainColor, 0.15)};

            // Fill the meter background with the background gradient
            m.addRing(0, outerRadius, m.relativeRadialGradient(bgGradient, outerRadius * 0.66));

            // Fill the inner circle with the same background gradient for decoration
            m.addRing(0, innerRadius, m.relativeRadialGradient(bgGradient, innerRadius * 0.8));

            // Gradient for the neon backlight, with the main color at the scale radius fading to
            // transparent
            double[] neonGradient = {0.89, Chart.Transparent, 1, mainColor, 1.07, Chart.Transparent};
            m.addRing(scaleRadius * 85 / 100, outerRadius, m.relativeRadialGradient(neonGradient));

            // The neon ring at the scale radius with width equal to 1/80 of the scale radius, creating
            // using a brighter version of the main color
            m.addRing(scaleRadius, scaleRadius + scaleRadius / 80, m.adjustBrightness(mainColor, 2));

            // Meter scale is 0 - 100, with major/minor/micro ticks every 10/5/1 units
            m.setScale(0, 100, 10, 5, 1);

            // Set the scale label style, tick length and tick width. The minor and micro tick lengths
            // are 80% and 60% of the major tick length, and their widths are around half of the major
            // tick width.
            m.setLabelStyle("Arial Italic", fontSize);
            m.setTickLength(-tickLength, -tickLength * 80 / 100, -tickLength * 60 / 100);
            m.setLineWidth(0, tickWidth, (tickWidth + 1) / 2, (tickWidth + 1) / 2);

            // Demostrate different types of color scales and glare effects and putting them at different
            // positions.
            double[] smoothColorScale = {0, 0x0000ff, 25, 0x0088ff, 50, 0x00ff00, 75, 0xdddd00, 100,
                0xff0000};
            double[] stepColorScale = {0, 0x00dd00, 60, 0xddaa00, 80, 0xdd0000, 100};
            double[] highColorScale = {70, Chart.Transparent, 100, 0xff0000};

            if (chartIndex == 1) {
                // Add the smooth color scale just outside the inner circle
                m.addColorScale(smoothColorScale, innerRadius + 1, colorScaleWidth);
                // Add glare up to the scale radius, concave and spanning 190 degrees
                m.addGlare(scaleRadius, -190);
            } else if (chartIndex == 2) {
                // Add the high color scale at the default position
                m.addColorScale(highColorScale);
                // Add glare up to the scale radius
                m.addGlare(scaleRadius);
            } else {
                // Add the step color scale just outside the inner circle
                m.addColorScale(stepColorScale, innerRadius + 1, colorScaleWidth);
                // Add glare up to the scale radius, concave and spanning 190 degrees and rotated by -45
                // degrees
                m.addGlare(scaleRadius, -190, -45);
            }

            // Add a red (0xff0000) pointer at the specified value
            m.addPointer2(value, 0xff0000);

            // Set the cap background to a brighter version of the mainColor, and using black (0x000000)
            // for the cap and grey (0x999999) for the cap border
            m.setCap2(m.adjustBrightness(mainColor, 1.1), 0x000000, 0x999999);

            // Output the chart
            viewer.Image = m.makeWebImage(Chart.PNG);
        }
    }
}

[ASP.NET MVC - View] NetMvcCharts\Views\Shared\ChartView.cshtml
@{ Layout = null; }

<!DOCTYPE html>

<html>
<head>
    <meta name="viewport" content="width=device-width" />
    <title>@ViewBag.Title</title>
</head>
<body style="margin:5px 0px 0px 5px">
    <div style="font:bold 18pt verdana;">
        @ViewBag.Title
    </div>
    <hr style="border:solid 1px #000080" />
    <div>
        @{
            if (ViewBag.Viewer is Array)
            {
                // Display multiple charts
                for (int i = 0; i < ViewBag.Viewer.Length; ++i)
                {
                    @:@Html.Raw(ViewBag.Viewer[i].RenderHTML())
                }
            }
            else
            {
                // Display one chart only
                @:@Html.Raw(ViewBag.Viewer.RenderHTML())
            }
        }
    </div>
</body>
</html>