Xamarin.Forms Behaviors: InvokeCommandAction and ConverterParameter davidbritch.com


I previously mentioned that I’d published v1.4 of my Behaviors library, and that it included some new functionality. In my last blog post I looked at the SourceObject property that’s now present on the EventHandlerBehavior class. The final new item is the ConverterParameter property that now exists on the InvokeCommandAction class.

The InvokeCommandAction class executes a specified ICommand when invoked. It requires you to set a Command property to an ICommand instance, and CommandParameter and Converter properties can be optionally set. The CommandParameter property should be set to an object instance, with the Converter property being set to an instance of a class that implements IValueConverter. The ICommand specified in the Command property will then be executed when the “something” the parent behavior listens for occurs, with the CommandParameter and Converter values being used if specified.

Introducing the ConverterParameter Property

In v1.4 of the Behaviors library, the InvokeCommandAction class also has an optional ConverterParameter property, of type object. When this property is set, its value is passed to the Convert and ConvertBack methods of the IValueConverter implementation, as the parameter argument.

The following XAML shows an example of the InvokeCommandAction passing a parameter to the converter:


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--><ListView x:Name="listView" ItemsSource="{Binding People}">
<behaviors:EventHandlerBehavior EventName="ItemSelected">
<behaviors:InvokeCommandAction Command="{Binding OutputAgeCommand}"
="{StaticResource SelectedItemConverter}"

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