用于 TreeView SelectedItemChanged 事件的 Caliburn Micro“找不到方法事件的目标...”

Question

I am having an issue with the following (just showing snippets of my code):

XAML:

    <TreeView Name="TypeTree" ItemsSource="{Binding TypeTreeItems}" 
      cal:Message.Attach="[Event SelectedItemChanged] = Action[SetSelectedType($this.SelectedItem)]">
            <TreeView.ItemTemplate>
                   <HierarchicalDataTemplate ItemsSource="{Binding Path=mChildren}">
                       <TextBlock Text="{Binding Path=mNodeName}"/>
                   </HierarchicalDataTemplate>
               </TreeView.ItemTemplate>
           </TreeView>

ViewModel:

    public void SetSelectedType(TreeNode item) 
    {
        MessageBox.Show("Here");
        _selectedType = item;
    }

System.Exception: 'No target found for method Event SelectedItemChanged = ActionSetSelectedSource.'

I'm still new to MVVM and Caliburn Micro so am not sure what is causing the issue. Anyone able to provide a bit of guidance as to where I've gone wrong? Happy to provide more snippets if it helps!

Thanks!

Answer 1

The syntax is wrong. Try this:

cal:Message.Attach="[Event SelectedItemChanged] = [Action SetSelectedType($this.SelectedItem)]"