The difference between tooltip format and template in WebForms Chart

When you move the mouse over a particular point, tooltip displays the values of that point. By default its display format looks like “x value :  y value (eg:  2000: 20)”.

Tooltip format

You can customize the values displayed in tooltip using format property. The online sample using tooltip format is available in the following link.

https://asp.syncfusion.com/demos/web/chart/symbols.aspx

Tooltip template

Tooltip template refers to using HTML elements like image, tables in tooltip through template property of tooltip. Since HTML elements such as div, image, table, etc., are used, you can style the tooltip template using CSS and it appears more attractive than default tooltip. The online sample for tooltip template is available in the following link.

https://asp.syncfusion.com/demos/web/chart/tooltiptemplate.aspx

Difference between tooltip format and template

In general, tooltip format is used to format the values displayed in tooltip whereas tooltip template is used to customize the appearance of tooltip.

In the following code example, the first series is rendered with tooltip template, next with specified tooltip format and the last series is rendered with default tooltip.

 ASP

<%--Div element used as template for tooltip--%>
    <div id="Tooltip" style="display: none">Year : #point.x# <br> Percent : #point.y# %</div>
    <ej:Chart ID="container" runat="server">
        <Series>
           <ej:Series Name="India" Type="Spline">
               <%--ID of a html element should be used in template property--%>
               <Tooltip Visible="true" Template="Tooltip"></Tooltip>               
           </ej:Series>
            <ej:Series Name="India" Type="Spline">
               <Tooltip Visible="true" Format="#point.x# <br/> #point.y#"></Tooltip>               
           </ej:Series>
            <ej:Series Name="India" Type="Spline">
               <Tooltip Visible="true"></Tooltip>               
           </ej:Series>
        </Series>
    </ej:Chart>

The output of the above code example is as follows.

Figure 1: Chart with Tooltip template