4 Answers, 1 is accepted
The hover and selection interactivity is supported for all 2D series types (note that "selection" for pie and doughnut types is implemented in the form of exploding the respective item slices). The interactivity support is disabled by default and can be controlled through the Interactivity API under SeriesDefinition.InteractivitySettings complex property:
• HoverScope - Gets or sets a value indicating the scope of interactivity for hover effects.
• SelectionScope - Gets or sets a value indicating the scope of interactivity for selection effects.
• SelectionMode - Gets or sets a value indicating the selection mode used by the chart control (single item or multiple items).
In order to enable the interactivity functionality you need to first set the interactivity scope for hover, selection, or both. The notion of "interactivity scope" specifies whether the chart control should interpret the interactivity action (selection or hover) on series level (if applicable), or on item level (if applicable).
Note that InteractivityScope.Item is not supported for series that do not render separate items (Line, Spline, Area, Range, and all their stacked versions), while InteractivityScope.Series is not supported for radial series (Pie and Doughnut).
For example if HoverScope is set to InteractivityScope.Series for a given bar series, when one hovers over a bar item, the whole series will be highlighted (i.e. all of the other series within the ChartArea will become temporarily transparent); otherwise if HoverScope is set to InteractivityScope.Item, when one hovers over a bar item, only the respective item will be highlighted (i.e. all of the other series as well all of the other bar items within the originating bar series will become temporarily transparent). The same principle applies for SelectionScope as well -- if it is set to InteractivityScope.Series, all items within the series will be selected; alternatively if it set to InteractivtyScope.Item, only the respective item will be selected.
There is one additional setting related to hover effects that can be set on global level - RadChart.HoverActivationDelay. This property gets or sets the delay before the hover effect is activated (by default there is no delay and the hover effect becomes active immediately).
You can find online example here and here is a short introductory video as well.
Hope this helps.
the Telerik team
Could you confirm you are using the latest version of the control (2010.2 714.1040)? We have attached a runnable sample application that demonstrates the availability of the hover / selection interactivity in our local tests.
Hope this helps.
the Telerik team
I discovered at least one cause of this issue today. For reasons I do not fully understand, having more than one version of the Silverlight 4 controls installed creates this issue.
I spent about 2.5 hours trying to figure out why I was unable to see the InteractivitySettings class on 2 of 3 development machines. I had both Q1 2010 SP2 (RadControls_for_Silverlight_4_2010_2_0714_DEV) and Q2 2010 SP1 (RadControls_for_Silverlight_4_2010_2_0812_DEV) installed on the machines that were failing. After uninstalling the Q1 2010 SP2 install I was able to see and use the InteractivitySettings on those machines.
Certainly was a confusing one.