Spline Area in ASP.NET CORE Charts Component

13 Dec 202424 minutes to read

Spline Area

To render a spline area series in your chart, you need to follow a few steps to configure it correctly. Here’s a concise guide on how to do this:

  • Set the series type: Define the series type as SplineArea in your chart configuration. This indicates that the data should be represented as a spline area chart, where data points are connected by smooth, curved lines (splines) instead of straight lines.
<ejs-chart id="container" title="Olympic Medals" width="60%">
    <e-chart-primaryxaxis valueType="Category">
    </e-chart-primaryxaxis>
    <e-series-collection>
        <e-series dataSource="ViewBag.dataSource" xName="x" yName="y"
            type="@Syncfusion.EJ2.Charts.ChartSeriesType.SplineArea"></e-series>
    </e-series-collection>
</ejs-chart>
public ActionResult Index()
        {
            List<AxisLabelData> chartData = new List<AxisLabelData>
            {
                new AxisLabelData { x= "South Korea", y= 39.4 },
                new AxisLabelData { x= "India", y= 61.3 }, 
                new AxisLabelData { x= "Pakistan", y= 20.4 },
                new AxisLabelData { x= "Germany", y= 65.1 }, 
                new AxisLabelData { x= "Australia", y= 15.8 },
                new AxisLabelData { x= "Italy", y= 29.2 },
                new AxisLabelData { x= "United Kingdom", y= 44.6 },
                new AxisLabelData { x= "Saudi Arabia", y= 9.7 },
                new AxisLabelData { x= "Russia", y= 40.8 },
                new AxisLabelData { x= "Mexico", y= 31 },
                new AxisLabelData { x= "Brazil", y= 75.9 },
                new AxisLabelData { x= "China", y= 51.4 }
            };
            ViewBag.dataSource = chartData;
            return View();
        }
        public class AxisLabelData
        {
            public string x;
            public double y;
        }

Binding data with series

You can bind data to the chart using the dataSource property within the series configuration. This allows you to connect a JSON dataset or remote data to your chart. To display the data correctly, map the fields from the data to the chart series xName and yName properties.

<ejs-chart id="container" title="Olympic Medals" width="60%">
    <e-chart-primaryxaxis valueType="Category">
    </e-chart-primaryxaxis>
    <e-series-collection>
        <e-series dataSource="ViewBag.dataSource" xName="x" yName="y"
            type="@Syncfusion.EJ2.Charts.ChartSeriesType.SplineArea"></e-series>
    </e-series-collection>
</ejs-chart>
public ActionResult Index()
        {
            List<AxisLabelData> chartData = new List<AxisLabelData>
            {
                new AxisLabelData { x= "South Korea", y= 39.4 },
                new AxisLabelData { x= "India", y= 61.3 }, 
                new AxisLabelData { x= "Pakistan", y= 20.4 },
                new AxisLabelData { x= "Germany", y= 65.1 }, 
                new AxisLabelData { x= "Australia", y= 15.8 },
                new AxisLabelData { x= "Italy", y= 29.2 },
                new AxisLabelData { x= "United Kingdom", y= 44.6 },
                new AxisLabelData { x= "Saudi Arabia", y= 9.7 },
                new AxisLabelData { x= "Russia", y= 40.8 },
                new AxisLabelData { x= "Mexico", y= 31 },
                new AxisLabelData { x= "Brazil", y= 75.9 },
                new AxisLabelData { x= "China", y= 51.4 }
            };
            ViewBag.dataSource = chartData;
            return View();
        }
        public class AxisLabelData
        {
            public string x;
            public double y;
        }

Series customization

The following properties can be used to customize the spline area series.

Fill

The fill property determines the color applied to the series.

<ejs-chart id="container" title="Olympic Medals" width="60%">
    <e-chart-primaryxaxis valueType="Category">
    </e-chart-primaryxaxis>
    <e-series-collection>
        <e-series dataSource="ViewBag.dataSource" xName="x" yName="y"
                  type="@Syncfusion.EJ2.Charts.ChartSeriesType.SplineArea" fill="blue"></e-series>
    </e-series-collection>
</ejs-chart>
public ActionResult Index()
        {
            List<AxisLabelData> chartData = new List<AxisLabelData>
            {
                new AxisLabelData { x= "South Korea", y= 39.4 },
                new AxisLabelData { x= "India", y= 61.3 }, 
                new AxisLabelData { x= "Pakistan", y= 20.4 },
                new AxisLabelData { x= "Germany", y= 65.1 }, 
                new AxisLabelData { x= "Australia", y= 15.8 },
                new AxisLabelData { x= "Italy", y= 29.2 },
                new AxisLabelData { x= "United Kingdom", y= 44.6 },
                new AxisLabelData { x= "Saudi Arabia", y= 9.7 },
                new AxisLabelData { x= "Russia", y= 40.8 },
                new AxisLabelData { x= "Mexico", y= 31 },
                new AxisLabelData { x= "Brazil", y= 75.9 },
                new AxisLabelData { x= "China", y= 51.4 }
            };
            ViewBag.dataSource = chartData;
            return View();
        }
        public class AxisLabelData
        {
            public string x;
            public double y;
        }

The fill property can be used to apply a gradient color to the spline area series. By configuring this property with gradient values, you can create a visually appealing effect in which the color transitions smoothly from one shade to another.

<svg style="width:1px; height:1px">
    <defs>
        <linearGradient id="gradient">
            <stop offset="0%" style="stop-color:#FF0000;stop-opacity:5" />
            <stop offset="70%" style="stop-color:#00FF00;stop-opacity:5" />
        </linearGradient>
    </defs>
</svg>

<ejs-chart id="container" title="Olympic Medals" width="60%">
    <e-chart-primaryxaxis valueType="Category">
    </e-chart-primaryxaxis>
    <e-series-collection>
        <e-series dataSource="ViewBag.dataSource" xName="x" yName="y"
                  type="@Syncfusion.EJ2.Charts.ChartSeriesType.SplineArea" fill="url(#gradient)"></e-series>
    </e-series-collection>
</ejs-chart>
public ActionResult Index()
        {
            List<AxisLabelData> chartData = new List<AxisLabelData>
            {
                new AxisLabelData { x= "South Korea", y= 39.4 },
                new AxisLabelData { x= "India", y= 61.3 }, 
                new AxisLabelData { x= "Pakistan", y= 20.4 },
                new AxisLabelData { x= "Germany", y= 65.1 }, 
                new AxisLabelData { x= "Australia", y= 15.8 },
                new AxisLabelData { x= "Italy", y= 29.2 },
                new AxisLabelData { x= "United Kingdom", y= 44.6 },
                new AxisLabelData { x= "Saudi Arabia", y= 9.7 },
                new AxisLabelData { x= "Russia", y= 40.8 },
                new AxisLabelData { x= "Mexico", y= 31 },
                new AxisLabelData { x= "Brazil", y= 75.9 },
                new AxisLabelData { x= "China", y= 51.4 }
            };
            ViewBag.dataSource = chartData;
            return View();
        }
        public class AxisLabelData
        {
            public string x;
            public double y;
        }

Opacity

The opacity property specifies the transparency level of the fill. Adjusting this property allows you to control how opaque or transparent the fill color of the series appears.

<ejs-chart id="container" title="Olympic Medals" width="60%">
    <e-chart-primaryxaxis valueType="Category">
    </e-chart-primaryxaxis>
    <e-series-collection>
        <e-series dataSource="ViewBag.dataSource" xName="x" yName="y" type="@Syncfusion.EJ2.Charts.ChartSeriesType.SplineArea"
                  opacity="0.5"></e-series>
    </e-series-collection>
</ejs-chart>
public ActionResult Index()
        {
            List<AxisLabelData> chartData = new List<AxisLabelData>
            {
                new AxisLabelData { x= "South Korea", y= 39.4 },
                new AxisLabelData { x= "India", y= 61.3 }, 
                new AxisLabelData { x= "Pakistan", y= 20.4 },
                new AxisLabelData { x= "Germany", y= 65.1 }, 
                new AxisLabelData { x= "Australia", y= 15.8 },
                new AxisLabelData { x= "Italy", y= 29.2 },
                new AxisLabelData { x= "United Kingdom", y= 44.6 },
                new AxisLabelData { x= "Saudi Arabia", y= 9.7 },
                new AxisLabelData { x= "Russia", y= 40.8 },
                new AxisLabelData { x= "Mexico", y= 31 },
                new AxisLabelData { x= "Brazil", y= 75.9 },
                new AxisLabelData { x= "China", y= 51.4 }
            };
            ViewBag.dataSource = chartData;
            return View();
        }
        public class AxisLabelData
        {
            public string x;
            public double y;
            public string color;
        }

Border

Use the border property to customize the width, color and dasharray of the series border.

<ejs-chart id="container" title="Olympic Medals" width="60%">
    <e-chart-primaryxaxis valueType="Category">
    </e-chart-primaryxaxis>
    <e-series-collection>
        <e-series dataSource="ViewBag.dataSource" xName="x" yName="y" type="@Syncfusion.EJ2.Charts.ChartSeriesType.Spline"
                  dashArray="5,5"></e-series>
            <e-series-border width="2" color="green" dashArray="5,5"></e-series-border>
    </e-series-collection>
</ejs-chart>
public ActionResult Index()
        {
            List<AxisLabelData> chartData = new List<AxisLabelData>
            {
                new AxisLabelData { x= "South Korea", y= 39.4 },
                new AxisLabelData { x= "India", y= 61.3 }, 
                new AxisLabelData { x= "Pakistan", y= 20.4 },
                new AxisLabelData { x= "Germany", y= 65.1 }, 
                new AxisLabelData { x= "Australia", y= 15.8 },
                new AxisLabelData { x= "Italy", y= 29.2 },
                new AxisLabelData { x= "United Kingdom", y= 44.6 },
                new AxisLabelData { x= "Saudi Arabia", y= 9.7 },
                new AxisLabelData { x= "Russia", y= 40.8 },
                new AxisLabelData { x= "Mexico", y= 31 },
                new AxisLabelData { x= "Brazil", y= 75.9 },
                new AxisLabelData { x= "China", y= 51.4 }
            };
            ViewBag.dataSource = chartData;
            ChartBorder border = new ChartBorder();
            border.Width = 2;
            border.Color = "green";
            border.DashArray="5,5";
            ViewBag.border = border;
            return View();
        }
        public class AxisLabelData
        {
            public string x;
            public double y;
            public string color;
        }

Empty points

Data points with null or undefined values are considered empty. Empty data points are ignored and not plotted on the chart.

Mode

Use the mode property to define how empty or missing data points are handled in the series. The default mode for empty points is Gap.

<ejs-chart id="container" title="Olympic Medals" width="60%">
    <e-chart-primaryxaxis valueType="Category">
    </e-chart-primaryxaxis>
    <e-series-collection>
        <e-series dataSource="ViewBag.dataSource" xName="month" yName="sales"
                  type="@Syncfusion.EJ2.Charts.ChartSeriesType.SplineArea">
            <e-series-emptypointsettings mode="Syncfusion.EJ2.Charts.EmptyPointMode.Zero"></e-series-emptypointsettings>
        </e-series>
    </e-series-collection>
</ejs-chart>
public ActionResult Index()
{
    List<AxisLabelData> chartData = new List<AxisLabelData>
        {
            new AxisLabelData { month = "Jan", sales = 35 },
            new AxisLabelData { month = "Feb", sales = 28 },
            new AxisLabelData { month = "Mar", sales = 34 },
            new AxisLabelData { month = "Apr", sales = null },
            new AxisLabelData { month = "May", sales = 40 },
            new AxisLabelData { month = "Jun", sales = 32 },
            new AxisLabelData { month = "Jul", sales = 35 },
            new AxisLabelData { month = "Aug" },
            new AxisLabelData { month = "Sep", sales = 38 },
            new AxisLabelData { month = "Oct", sales = 30 },
            new AxisLabelData { month = "Nov", sales = 25 },
            new AxisLabelData { month = "Dec", sales = 32 },
        };
        ViewBag.dataSource = chartData;
        ChartEmptyPointSettings chartEmptyPointSettings = new ChartEmptyPointSettings();
        chartEmptyPointSettings.Mode = EmptyPointMode.Zero;
        ViewBag.emptyPoint = chartEmptyPointSettings;
        return View();
}


public class AxisLabelData
{
    public string month;
    public double? sales;
}

Fill

Use the fill property to customize the fill color of empty points in the series.

<ejs-chart id="container" title="Olympic Medals" width="60%">
    <e-chart-primaryxaxis valueType="Category">
    </e-chart-primaryxaxis>
    <e-series-collection>
        <e-series dataSource="ViewBag.dataSource" xName="month" yName="sales"
                  type="@Syncfusion.EJ2.Charts.ChartSeriesType.SplineArea">
            <e-series-marker visible="true" width="7" height="7" isFilled="true"></e-series-marker>
            <e-series-emptypointsettings fill="red" mode="@Syncfusion.EJ2.Charts.EmptyPointMode.Zero"></e-series-emptypointsettings>
        </e-series>
    </e-series-collection>
</ejs-chart>
public ActionResult Index()
{
    List<AxisLabelData> chartData = new List<AxisLabelData>
        {
            new AxisLabelData { month = "Jan", sales = 35 },
            new AxisLabelData { month = "Feb", sales = 28 },
            new AxisLabelData { month = "Mar", sales = 34 },
            new AxisLabelData { month = "Apr", sales = null },
            new AxisLabelData { month = "May", sales = 40 },
            new AxisLabelData { month = "Jun", sales = 32 },
            new AxisLabelData { month = "Jul", sales = 35 },
            new AxisLabelData { month = "Aug" },
            new AxisLabelData { month = "Sep", sales = 38 },
            new AxisLabelData { month = "Oct", sales = 30 },
            new AxisLabelData { month = "Nov", sales = 25 },
            new AxisLabelData { month = "Dec", sales = 32 },
        };
        ViewBag.dataSource = chartData;
        ChartEmptyPointSettings chartEmptyPointSettings = new ChartEmptyPointSettings();
        chartEmptyPointSettings.Mode = EmptyPointMode.Zero;
        chartEmptyPointSettings.Fill = "red";
        ViewBag.emptyPoint = chartEmptyPointSettings;
        ChartMarkerSettings marker = new ChartMarkerSettings();
        marker.Visible = true;
        marker.Width = 7;
        marker.Height = 7;
        marker.IsFilled = true;
        ViewBag.marker = marker;
        return View();
}


public class AxisLabelData
{
    public string month;
    public double? sales;
}

Border

Use the border property to customize the width and color of the border for empty points.

<ejs-chart id="container" title="Olympic Medals" width="60%">
    <e-chart-primaryxaxis valueType="Category">
    </e-chart-primaryxaxis>
    <e-series-collection>
        <e-series dataSource="ViewBag.dataSource" xName="month" yName="sales"
                  type="@Syncfusion.EJ2.Charts.ChartSeriesType.SplineArea">
            <e-series-marker visible="true" width="7" height="7" isFilled="true"></e-series-marker>
            <e-series-emptypointsettings fill="red" mode="@Syncfusion.EJ2.Charts.EmptyPointMode.Zero">
                <e-emptypointsettings-border width="2" color="green"></e-emptypointsettings-border>
            </e-series-emptypointsettings>
        </e-series>
    </e-series-collection>
</ejs-chart
public ActionResult Index()
{
    List<AxisLabelData> chartData = new List<AxisLabelData>
        {
            new AxisLabelData { month = "Jan", sales = 35 },
            new AxisLabelData { month = "Feb", sales = 28 },
            new AxisLabelData { month = "Mar", sales = 34 },
            new AxisLabelData { month = "Apr", sales = null },
            new AxisLabelData { month = "May", sales = 40 },
            new AxisLabelData { month = "Jun", sales = 32 },
            new AxisLabelData { month = "Jul", sales = 35 },
            new AxisLabelData { month = "Aug" },
            new AxisLabelData { month = "Sep", sales = 38 },
            new AxisLabelData { month = "Oct", sales = 30 },
            new AxisLabelData { month = "Nov", sales = 25 },
            new AxisLabelData { month = "Dec", sales = 32 },
        };
        ViewBag.dataSource = chartData;
        ChartEmptyPointSettings chartEmptyPointSettings = new ChartEmptyPointSettings();
        chartEmptyPointSettings.Mode = EmptyPointMode.Zero;
        chartEmptyPointSettings.Fill = "red";
        chartEmptyPointSettings.Border.Width = 2;
        chartEmptyPointSettings.Border.Color = "green";
        ViewBag.emptyPoint = chartEmptyPointSettings;
        ChartMarkerSettings marker = new ChartMarkerSettings();
        marker.Visible = true;
        marker.Width = 7;
        marker.Height = 7;
        marker.IsFilled = true;
        ViewBag.marker = marker;
        return View();
}


public class AxisLabelData
{
    public string month;
    public double? sales;
}

Events

Series render

The seriesRender event allows you to customize series properties, such as data, fill, and name, before they are rendered on the chart.

<ejs-chart id="container" title="Olympic Medals" seriesRender="changeColor" width="60%">
    <e-chart-primaryxaxis valueType="Category">
    </e-chart-primaryxaxis>
    <e-series-collection>
        <e-series dataSource="ViewBag.dataSource" xName="month" yName="sales"
                  type="@Syncfusion.EJ2.Charts.ChartSeriesType.SplineArea" width="2">
        </e-series>
    </e-series-collection>
</ejs-chart>

<script>
    function changeColor(args) {
        args.fill = '#ff6347';
    }
</script>
public ActionResult Index()
{
    List<AxisLabelData> chartData = new List<AxisLabelData>
    {
        new AxisLabelData { month = "Jan", sales = 35 },
        new AxisLabelData { month = "Feb", sales = 28 },
        new AxisLabelData { month = "Mar", sales = 34 },
        new AxisLabelData { month = "Apr", sales = 30 },
        new AxisLabelData { month = "May", sales = 40 },
        new AxisLabelData { month = "Jun", sales = 32 },
        new AxisLabelData { month = "Jul", sales = 35 },
        new AxisLabelData { month = "Aug", sales = 43 },
        new AxisLabelData { month = "Sep", sales = 38 },
        new AxisLabelData { month = "Oct", sales = 30 },
        new AxisLabelData { month = "Nov", sales = 25 },
        new AxisLabelData { month = "Dec", sales = 32 },
    };
    ViewBag.dataSource = chartData;
    return View();
}
public class AxisLabelData
{
    public string month;
    public double? sales;
}

Point render

The pointRender event allows you to customize each data point before it is rendered on the chart.

<ejs-chart id="container" title="Olympic Medals" pointRender="changeColor" width="60%">
    <e-chart-primaryxaxis valueType="Category">
    </e-chart-primaryxaxis>
    <e-series-collection>
        <e-series dataSource="ViewBag.dataSource" xName="month" yName="sales"
                  type="@Syncfusion.EJ2.Charts.ChartSeriesType.SplineArea" width="2">
            <e-series-marker visible="true" width="7" height="7" isFilled="true"></e-series-marker>
        </e-series>
    </e-series-collection>
</ejs-chart>

<script>
    function changeColor(args) {
        if (args.point.index % 2 !== 0) {
            args.fill = '#ff6347';
        }
        else {
            args.fill = '#009cb8';
        }
    }
</script>
public ActionResult Index()
{
    List<AxisLabelData> chartData = new List<AxisLabelData>
    {
        new AxisLabelData { month = "Jan", sales = 35 },
        new AxisLabelData { month = "Feb", sales = 28 },
        new AxisLabelData { month = "Mar", sales = 34 },
        new AxisLabelData { month = "Apr", sales = 30 },
        new AxisLabelData { month = "May", sales = 40 },
        new AxisLabelData { month = "Jun", sales = 32 },
        new AxisLabelData { month = "Jul", sales = 35 },
        new AxisLabelData { month = "Aug", sales = 43 },
        new AxisLabelData { month = "Sep", sales = 38 },
        new AxisLabelData { month = "Oct", sales = 30 },
        new AxisLabelData { month = "Nov", sales = 25 },
        new AxisLabelData { month = "Dec", sales = 32 },
    };
    ViewBag.dataSource = chartData;
    ChartMarkerSettings chartMarkerSettings = new ChartMarkerSettings();
    chartMarkerSettings.Visible = true;
    chartMarkerSettings.IsFilled = true;
    chartMarkerSettings.Height = 7;
    chartMarkerSettings.Width = 7;
    ViewBag.marker = chartMarkerSettings;
    return View();
}
public class AxisLabelData
{
    public string month;
    public double? sales;
}

See Also