ComponentOne ASP.NET MVC Edition
Working with Controls / FlexChart / Work with FlexChart / Hit Test
Hit Test

The HitTest() method is used to determine X and Y coordinates, as well as the index of a point on the FlexChart where the mouse hovers.

The following image shows how labels below the chart display the X, Y coordinate values and the index of the hit point on FlexChart.

The following code examples demonstrate how to display the X, Y coordinate values and index of the hit point using simple labels.

  1. Instantiate a FlexChart as shown below.
    HTML
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    <div id="HitTest" style="height: 300px"></div>
<c1-flex-chart id="HitTest" chart-type="ChartType.LineSymbols">
    <c1-flex-chart-series binding-x="X" binding="Y" name="cos(x)">
        <c1-items-source source-collection="cos"></c1-items-source>
    </c1-flex-chart-series>
    <c1-flex-chart-series binding-x="X" binding="Y" name="sin(x)">
        <c1-items-source source-collection="sin"></c1-items-source>
    </c1-flex-chart-series>
</c1-flex-chart>
  2. Add a <div> tag just below the FlexChart to display the information of the hit point as shown below.
    Razor
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    <div id="info"></div>
  3. Add the following script that retrieves the X, Y coordinate values and index of the hit point and displays them in the division added just below the chart.
    JavaScript
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    <script type="text/javascript">
    c1.mvc.Utils.documentReady(function ()
    {
        var chart = wijmo.Control.getControl("#flexChart1"),
            formatHitInfo = function (hitInfo, pt)
            {
                var s = '<div><b>Chart element</b>: ' + wijmo.chart.ChartElement[hitInfo.chartElement] + '</div>';
                if (hitInfo.series)
                {
                    s += '<div><b>Series name</b>: ' + hitInfo.series.name;
                    if (hitInfo.pointIndex !== null) {
                        s += '<div><b>Point index</b>: ' + hitInfo.pointIndex + '</div>';
                        if (hitInfo.chartElement == wijmo.chart.ChartElement.PlotArea)
                        {
                            s += '<div><b>x coordinate</b>: ' + pt.x.toFixed(2) + '</div>';
                            s += '<div><b>y coordinate</b>: ' + pt.y.toFixed(2) + '</div>';
                        }
                    }
                }
                return s;
            };
        chart.hostElement.onmousemove = function (e)
        {
            var hit = chart.hitTest(e);
            var info = document.getElementById("info");
            info.innerHTML = formatHitInfo(hit, chart.pointToData(e));
        };
    });
</script>