ASP.NET Chart Selection

To enable point selection you need to set the series setting’s EnablePointSelection property to true:

...
<DataSeries>
    <shield:ChartBarSeries DataFieldY="Sales">
        <Settings EnablePointSelection="true">
        </Settings>
    </shield:ChartBarSeries>
</DataSeries>

Live example you can find on this bar chart demo.

In order to set initially some point to be selected the Selected property of the point needs to be set to true:

protected override void OnPreRender(EventArgs e)
{
    base.OnPreRender(e);

    // select the third item of the first series
    (ShieldChart1.DataSeries[0] as ChartBarSeries).Items[2].Selected = true;
}

The ShieldChart also support multiple selection which can be achieved by holding Shift or Ctrl key and clicking on different points.

Handling selection on client

To handle point selection on the client the client side PointSelect and PointDeselect events can be handled and additional logic can be executed based on selection

Server side selection

To handle selection on the server side you can handle the OnSelectionChanged.
NOTE: In order to postback to the server when point is selected the chart AutoPostBack property needs to be set to true.

The ShiledChart gives ability for server side multi points selection without pressing Ctrl or Shift key when items are select. To enable this functionality you need to set AllowMultiItemSelection property to true.

Slicing

The pie and donut charts have slicing in advance to point selection. By default when selection is enabled the slicing of points are enabled too. If initially some point/points need to be sliced a Sliced property of each pie/donut item needs to be set to true:

<shield:ChartDonutSeries CollectionAlias="Test">
    <Items>
        <shield:ChartPieSeriesItem ValueX="1" ValueY="20" />
        <shield:ChartPieSeriesItem ValueX="2" ValueY="30" Sliced="true" />
        <shield:ChartPieSeriesItem ValueX="3" ValueY="50" />
    </Items>
</shield:ChartDonutSeries>

Live example you can find on this pie chart demo.