Generic routed event handler to command behavior
Imagine that you need to handle from the ViewModel the
SelectedIndexChangedof a WPF
TreeView, currently the only way (without using any particular framework) is to build your own behavior to achieve that, or bind, via a style the
IsSelectedproperty of the node to a property of the view model, but in this second case the side effect is that to find the selected item you need to visit the whole tree.
<TreeView Margin="5" HorizontalAlignment="Stretch" VerticalAlignment="Stretch"
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As you can imagine the value of the
NewValueproperty of the event arguments is passed as the command parameter to the command, we currently support as placeholder:
$args: the routed event arguments;
$this: the WPF element the behavior is attached to;
$source: the source of the routed event;
$originalSource: the original source of the routed event;
- the event identified by the
RoutedEventproperty must be a valid WPF
- the bound command identified by the
WithCommandproperty must be a valid
AutoCommandBindingis not supported.
The behavior is defined in the