Tooltip in Syncfusion ASP.NET MVC Chart Component

4 Apr 202524 minutes to read

Chart will display details about the points through tooltip, when the mouse is moved over the point.

The tooltip is useful when you cannot display information by using the data labels due to space constraints. You can enable the tooltip by setting Enable property as true in Tooltip object.

CSHTML
Default.cs
@Html.EJS().Chart("container").Series(series =>
   {
   series.Type(Syncfusion.EJ2.Charts.ChartSeriesType.Column).
   Marker(ViewBag.Marker).
   XName("x").
   YName("yValue").
   DataSource(ViewBag.dataSource).
   Name("Gold").
   Width(2).Add();
   }).
   PrimaryXAxis(px => px.Interval(1).ValueType(Syncfusion.EJ2.Charts.ValueType.Category)).
   Title("Olympic Medal Counts - RIO").Tooltip(tt => tt.Enable(true)).Render()
public IActionResult Index()
        {
            List<ColumnChartData> chartData = new List<ColumnChartData>
            {
                new ColumnChartData { x= "USA", yValue= 46 }, 
                new ColumnChartData { x= "GBR", yValue= 27 }, 
                new ColumnChartData { x= "CHN", yValue= 26 },
                new ColumnChartData { x= "UK", yValue= 26 },
                new ColumnChartData { x= "AUS", yValue= 26 },
                new ColumnChartData { x= "IND", yValue= 26 },
                new ColumnChartData { x= "DEN", yValue= 26 },
                new ColumnChartData { x= "MEX", yValue= 26 },
            };
            ViewBag.dataSource = chartData;
            return View();
        }
        public class ColumnChartData
        {
            public string x;
            public double yValue;
        }

By default, tooltip track the mouse movement, but you can set a fixed position for the tooltip by using the Location property.

CSHTML
Fixed.cs
@(Html.EJS().Chart("container").Series(series =>
{
   series.Type(Syncfusion.EJ2.Charts.ChartSeriesType.Column).
   XName("xValue").
   YName("yValue").
   DataSource(ViewBag.dataSource).
   Name("Gold").
   Width(2).Add();
}).
   PrimaryXAxis(px => px.Interval(1).ValueType(Syncfusion.EJ2.Charts.ValueType.Category)).LegendSettings(ls => ls.Visible(false))
   .Title("Olympic Medal Counts - RIO").Tooltip(tt => tt.Enable(true).Location(lc => lc.X(120).Y(20))).Render())
public IActionResult Index()
{
    List<ColumnChartData> chartData = new List<ColumnChartData>
    {
        new ColumnChartData { xValue= "USA", yValue= 46 }, 
        new ColumnChartData { xValue= "GBR", yValue= 27 }, 
        new ColumnChartData { xValue= "CHN", yValue= 26 },
        new ColumnChartData { xValue= "UK",  yValue= 26 },
        new ColumnChartData { xValue= "AUS", yValue= 26 },
        new ColumnChartData { xValue= "IND", yValue= 26 },
        new ColumnChartData { xValue= "DEN", yValue= 26 },
        new ColumnChartData { xValue= "MEX", yValue= 26 }
    };
    ViewBag.dataSource = chartData;
    return View();
}
public class ColumnChartData
{
    public string xValue;
    public double yValue;
}

By default, tooltip shows information of x and y value in points. In addition to that, you can show more information in tooltip. For example the format ${series.name} ${point.x} shows series name and point x value.

CSHTML
Format.cs
@Html.EJS().Chart("container").Series(series =>
   {
   series.Type(Syncfusion.EJ2.Charts.ChartSeriesType.Column).
   Marker(ViewBag.Marker).
   XName("x").
   YName("yValue").
   DataSource(ViewBag.dataSource).
   Name("Gold").
   Width(2).Add();
   }).
   PrimaryXAxis(px => px.Interval(1).ValueType(Syncfusion.EJ2.Charts.ValueType.Category)).
   Title("Olympic Medal Counts - RIO").
   Tooltip(tt => tt.Enable(true).
   Header("medal count").
   Format("${series.name} ${point.x} : ${point.y}")).Render()
public IActionResult Index()
        {
            List<ColumnChartData> chartData = new List<ColumnChartData>
            {
                new ColumnChartData { x= "USA", yValue= 46 }, 
                new ColumnChartData { x= "GBR", yValue= 27 }, 
                new ColumnChartData { x= "CHN", yValue= 26 },
                new ColumnChartData { x= "UK", yValue= 26 },
                new ColumnChartData { x= "AUS", yValue= 26 },
                new ColumnChartData { x= "IND", yValue= 26 },
                new ColumnChartData { x= "DEN", yValue= 26 },
                new ColumnChartData { x= "MEX", yValue= 26 },
            };
            ViewBag.dataSource = chartData;
            return View();
        }
        public class ColumnChartData
        {
            public string x;
            public double yValue;
        }

Any HTML elements can be displayed in the tooltip by using the Template property of the tooltip. You can use the ${x} and ${y} as place holders in the HTML element to display the x and y values of the corresponding data point.

CSHTML
Template.cs
@Html.EJS().Chart("container").Series(series =>
   {
   series.Type(Syncfusion.EJ2.Charts.ChartSeriesType.Column).
   Marker(ViewBag.Marker).
   XName("x").
   YName("yValue").
   DataSource(ViewBag.dataSource).
   Name("Gold").
   Width(2).Add();
   }).
   PrimaryXAxis(px => px.Interval(1).ValueType(Syncfusion.EJ2.Charts.ValueType.Category)).
   Title("Olympic Medal Counts - RIO").
   Tooltip(tt => tt.Enable(true).
   header("medal count").
   template=("#Medal")).Render()

    <script id="Medal" type="text/x-template">
      <div id='templateWrap'>
     <table style="width:100%;  border: 1px solid black;">
     <tr><th colspan="2" bgcolor="#00FFFF">Medal</th></tr>
     <tr><td bgcolor="#00FFFF">${x}:</td><td bgcolor="#00FFFF">${y}</td></tr>
    </table>
    </div>
  </script>
public IActionResult Index()
        {
            List<ColumnChartData> chartData = new List<ColumnChartData>
            {
                new ColumnChartData { x= "USA", yValue= 46 },
                new ColumnChartData { x= "GBR", yValue= 27 },
                new ColumnChartData { x= "CHN", yValue= 26 },
                new ColumnChartData { x= "UK", yValue= 26 },
                new ColumnChartData { x= "AUS", yValue= 26 },
                new ColumnChartData { x= "IND", yValue= 26 },
                new ColumnChartData { x= "DEN", yValue= 26 },
                new ColumnChartData { x= "MEX", yValue= 26 },
            };
            ViewBag.dataSource = chartData;
            return View();
        }
        public class ColumnChartData
        {
            public string x;
            public double yValue;
        }

The Fill and Border properties are used to customize the background color and border of the tooltip respectively. The TextStyle property in the tooltip is used to customize the font of the tooltip text. The HighlightColor property is used to customize the point color while hovering for tooltip.

CSHTML
Custom-tooltip.cs
@Html.EJS().Chart("container").Series(series =>
   {
   series.Type(Syncfusion.EJ2.Charts.ChartSeriesType.Column).
   Marker(ViewBag.Marker).
   XName("x").
   YName("yValue").
   DataSource(ViewBag.dataSource).
   Name("Gold").
   Width(2).Add();
   }).
   HighlightColor("red").
   PrimaryXAxis(px => px.Interval(1).ValueType(Syncfusion.EJ2.Charts.ValueType.Category)).
   Title("Olympic Medal Counts - RIO").Tooltip(tt => tt.Enable(true).
   Format("<b>${point.x} : ${point.y}</b>").
   Fill('#7bb4eb')).Render()
    }
public IActionResult Index()
        {
            List<ColumnChartData> chartData = new List<ColumnChartData>
            {
                new ColumnChartData { x= "USA", yValue= 46 },
                new ColumnChartData { x= "GBR", yValue= 27 },
                new ColumnChartData { x= "CHN", yValue= 26 },
                new ColumnChartData { x= "UK", yValue= 26 },
                new ColumnChartData { x= "AUS", yValue= 26 },
                new ColumnChartData { x= "IND", yValue= 26 },
                new ColumnChartData { x= "DEN", yValue= 26 },
                new ColumnChartData { x= "MEX", yValue= 26 },
            };
            ViewBag.dataSource = chartData;
            return View();
        }
        public class ColumnChartData
        {
            public string x;
            public double yValue;
        }

By default, tooltip shows information of x and y value in points. You can show more information from data source in tooltip by using the TooltipMappingName property of the tooltip. You can use the ${point.tooltip} as place holders to display the specified tooltip content.

CSHTML
Tooltip-mapping.cs
@(Html.EJS().Chart("container").Series(series =>
{
    series.Type(Syncfusion.EJ2.Charts.ChartSeriesType.Column).
        XName("xValue").
        YName("yValue").
        TooltipMappingName("text").
        DataSource(ViewBag.dataSource).
        Name("Gold").
        Width(2).Add();
}).
   PrimaryXAxis(px => px.ValueType(Syncfusion.EJ2.Charts.ValueType.Category).Interval(1))
   .Tooltip(tp => tp.Enable(true).Format("${point.tooltip}"))
   .Render()
)
public ActionResult Index()
        {
            List<GroupingChartData> chartData = new List<GroupingChartData>
            {

                new GroupingChartData { xValue = "China",         yValue = 26, text = "China: 26" },
                new GroupingChartData { xValue = "Russia",        yValue = 19, text = "Russia: 19" },
                new GroupingChartData { xValue = "Germany",       yValue = 17, text = "Germany: 17" },
                new GroupingChartData { xValue = "Japan",         yValue = 12, text = "Japan: 12" },
                new GroupingChartData { xValue = "France",        yValue = 10, text = "France: 10" },
                new GroupingChartData { xValue = "South Korea",   yValue = 9,  text = "South Korea: 9" },
                new GroupingChartData { xValue = "Great Britain", yValue = 27, text = "Great Britain: 27" },
                new GroupingChartData { xValue = "Italy",         yValue = 8,  text = "Italy: 8" },
                new GroupingChartData { xValue = "Australia",     yValue = 8,  text = "Australia: 8" },
                new GroupingChartData { xValue = "Netherlands",   yValue = 8,  text = "Netherlands: 8" },
                new GroupingChartData { xValue = "Hungary",       yValue = 8,  text = "Hungary: 8" },
                new GroupingChartData { xValue = "Brazil",        yValue = 7,  text = "Brazil: 7" },
                new GroupingChartData { xValue = "Spain",         yValue = 7,  text = "Spain: 7" },
                new GroupingChartData { xValue = "Kenya",         yValue = 6,  text = "Kenya: 6" }

            };
            ViewBag.dataSource = chartData;
            return View();
        }
        public class GroupingChartData
        {
            public string xValue;
            public double yValue;
            public string text;
        }

Enable highlight

By setting the EnableHighlight property to true, you can highlight all points in the hovered series while dimming points in other series, enhancing focus and clarity.

CSHTML
CSHTML.cs
<ejs-chart id="container">
    <e-chart-tooltipsettings enable="true" format="${point.tooltip}" enableHighlight="true">
    </e-chart-tooltipsettings>
    <e-chart-legendsettings visible="true"></e-chart-legendsettings>
    <e-chart-primaryxaxis valueType="Category"></e-chart-primaryxaxis>
    <e-series-collection>
        <e-series dataSource="ViewBag.dataSource" tooltipMappingName="text" name="Germany" xName="xValue" yName="yValue" type="@Syncfusion.EJ2.Charts.ChartSeriesType.Column">
        </e-series>
    </e-series-collection>
</ejs-chart>
...
public class GroupingChartData
{
    public string xValue;
    public double yValue;
    public string text;
}

The ShowNearestTooltip property in the chart tooltip displays tooltips based on the data points closest to the cursor.

CSHTML
Nearest-tooltip.cs
@Html.EJS().Chart("container").Series(series =>
   {
      series.Type(Syncfusion.EJ2.Charts.ChartSeriesType.StepLine)
            .XName("X")
            .YName("Y")
            .Marker(mr => mr.Visible(true).Width(10).Height(10))
            .Name("China")
            .Width(2)
            .DataSource(ViewBag.dataSource)
            .Add();

      series.Type(Syncfusion.EJ2.Charts.ChartSeriesType.StepLine)
            .XName("X")
            .YName("Y1")
            .Marker(mr => mr.Visible(true).Width(10).Height(10))
            .Name("Australia")
            .Width(2)
            .DataSource(ViewBag.dataSource)
            .Add();

      series.Type(Syncfusion.EJ2.Charts.ChartSeriesType.StepLine)
            .XName("X")
            .YName("Y2")
            .Marker(mr => mr.Visible(true).Width(10).Height(10))
            .Name("Japan")
            .Width(2)
            .DataSource(ViewBag.dataSource)
            .Add();
   }
   ).PrimaryXAxis(px => px.ValueType(Syncfusion.EJ2.Charts.ValueType.DateTime).EdgeLabelPlacement(Syncfusion.EJ2.Charts.EdgeLabelPlacement.Shift).Title("Years").LabelFormat("y").IntervalType(Syncfusion.EJ2.Charts.IntervalType.Years).LineStyle(ls=>ls.Width(0))
   ).PrimaryYAxis(py => py.Title("Percentage (%)").LabelFormat("{value}%").Minimum(0).Maximum(20).Interval(4)
   ).LegendSettings(leg => leg.Visible(true)).Title("Unemployment Rates 1975-2010").Tooltip(tt => tt.Enable(true).EnableHighlight(true).ShowNearestTooltip(true)).Render()
public IActionResult Index()
        {
            List<ColumnChartData> chartData = new List<ColumnChartData>
            {
                new ColumnChartData { X = new DateTime(1975, 01, 01), Y = 16,   Y1 = 10,  Y2 = 4.5 },
                new ColumnChartData { X = new DateTime(1980, 01, 01), Y = 12.5, Y1 = 7.5, Y2 = 5 },
                new ColumnChartData { X = new DateTime(1985, 01, 01), Y = 19,   Y1 = 11,  Y2 = 6.5 },
                new ColumnChartData { X = new DateTime(1990, 01, 01), Y = 14.4, Y1 = 7,   Y2 = 4.4 },
                new ColumnChartData { X = new DateTime(1995, 01, 01), Y = 11.5, Y1 = 8,   Y2 = 5 },
                new ColumnChartData { X = new DateTime(2000, 01, 01), Y = 14,   Y1 = 6,   Y2 = 1.5 },
                new ColumnChartData { X = new DateTime(2005, 01, 01), Y = 10,   Y1 = 3.5, Y2 = 2.5 },
                new ColumnChartData { X = new DateTime(2010, 01, 01), Y = 16,   Y1 = 7,   Y2 = 3.7 }
            };
            ViewBag.dataSource = chartData;
            return View();
        }
        public class ColumnChartData
        {
            public DateTime X;
            public double Y;
            public double Y1;
            public double Y2;
        }

Tooltip in ASP.NET MVC Chart Component

Enable tooltip

Fixed tooltip

Format the tooltip

Tooltip template

Customize the appearance of tooltip

Tooltip mapping name

Enable highlight

Closest tooltip