WinRT CaliburnMicro event binding to ListPickerFlyout

Question

The event binding of Caliburn.Micro seems not to work with the ListPickerFlyout of Windows Phone 8.1. I want to bind the event ItemsPicked of the Flyout to the corresponding method of my ViewModel.

    <ListView 
            x:Name="Links"
            toolkitex:ListViewExtensions.BindableSelection="{Binding Selection}"
            cm:Message.Attach="[Event ItemClick] = [Click($link)]">

        <FlyoutBase.AttachedFlyout>
            <ListPickerFlyout 
                SelectionMode="Single"
                Placement="Full"
                ItemsSource="{Binding Lists}"
                SelectedItem="{Binding SelectedList, Mode=TwoWay}"
                ctrls:FlyoutEx.Parent="{Binding ElementName=Links}"
                ctrls:FlyoutEx.IsOpen="{Binding IsListSelectionOpen, Mode=TwoWay}"
                cm:Message.Attach="[Event ItemsPicked] = [ItemsPicked($this, $eventArgs)]">
            </ListPickerFlyout>
        </FlyoutBase.AttachedFlyout>
    </ListView>

When the event will be raised, I get the following exception: No target found for method ItemsPicked.

System.Exception: No target found for method ItemsPicked. at Caliburn.Micro.ActionMessage.Invoke(Object eventArgs) at Caliburn.Micro.TriggerAction`1.Execute(Object sender, Object parameter) at Microsoft.Xaml.Interactivity.Interaction.ExecuteActions(Object sender, ActionCollection actions, Object parameter) at Microsoft.Xaml.Interactions.Core.EventTriggerBehavior.OnEvent(Object sender, Object eventArgs)

I also tried it without event and method method parameters but it does not work either.

Wouldn't it be easier to just get the "SelectedItems" property? Assuming the control does the heavy lifting for you? — mvermef, Oct 17 '15 at 00:17

score 0 · Answer 1 · answered Oct 16 '15 at 17:56

0

The problem occured becouse ListPickerFlyout doesn't have DataContext (or has wrong). I don't see a way to set the DataContext, but you can determine selected item by pinning to setter of your SelectedList property from ViewModel. For example if your SelectedList is type of string:

    private string _selectedLists;
    public string SelectedLists
    {
        get { return _selectedLists; }
        set
        {
            _selectedLists = value;

            ItemsPicked(value); // <----------------

            NotifyOfPropertyChange(() => SelectedLists);
        }
    }

    private void ItemsPicked(string selectedValue)
    {
        //Handle selection
    }

answered Oct 16 '15 at 17:56

marcinax

1,067
7
10

Datacontext is inherited from the object from which its attached. FlyoutBase.AttachedFlyout or `` as an example... https://msdn.microsoft.com/en-us/library/windows/apps/xaml/dn308515.aspx – mvermef Oct 16 '15 at 22:41
While it is part of the problem not knowing how he setup the ListPickerFlyout to begin with from a coding standing point it shouldn't be a allowed to free stand on the screen since it is a Flyout, has to be attached in some fashion. We don't have the whole picture in this instance presently. – mvermef Oct 16 '15 at 22:46
The ListPickerFlyout is attachted a ListView control. – zirkelc Oct 17 '15 at 12:25

WinRT CaliburnMicro event binding to ListPickerFlyout

1 Answers1