Question

I have a TreeView control on my window that depending on which selection the user picks should display a user control (figuring out which user control to display is complete). I’m having issues figuring out how to actually display the user control. Essentially, the user would select item from the TreeView and based on the selection a user control would appear (in a ContentControl control I’m assuming).

Currently, for opening new windows I have a window adapter where I can create new windows on the fly and set the parent.

How can I accomplish this in my view model?

Edit

Here is what I believe Rachel was talking about when she mentioned using DataTemplate‘s instead. Don’t be worried of my DataTemplates instead the DataType attribute. That’s simply the name of my project.

<Window.Resources>
    <DataTemplate DataType="{x:Type DataTemplates:FooEditorViewModel}">
        <DataTemplates:FooControl></DataTemplates:FooControl>
    </DataTemplate>
    <DataTemplate DataType="{x:Type DataTemplates:BarEditorViewModel}">
        <DataTemplates:BarControl></DataTemplates:BarControl>
    </DataTemplate>
</Window.Resources>

And here is a sample view model.

public class ViewModel
{
    public IEditorViewModel Editor
    {
        get
        {
            return new BarEditorViewModel();
        }
    }
}

And glue it all together with

<ContentControl Content="{Binding Editor}" />

I had to create a blank interface called IEditorViewModel in order to return different user control editors. Not sure if there’s any way around it.

Hopes this helps someone.

Answer 1

Your SelectedTreeViewItem would be stored in your ViewModel, and that value would be used to determine which item to display.

An example would be something like:

<ContentControl Content="{Binding SelectedItem}">
    <ContentControl.Style>
        <Style TargetType="{x:Type ContentControl}">
            <Setter Property="ContentTemplate" Value="{StaticResource DefaultTemplate}" />
            <Style.Triggers>
                <DataTrigger Binding="{Binding SelectedItem}" Value="{x:Type local:ItemA}">
                    <Setter Property="ContentTemplate" Value="{StaticResource TemplateA}" />
                </DataTrigger>
                <DataTrigger Binding="{Binding SelectedItem}" Value="{x:Type local:ItemB}">
                    <Setter Property="ContentTemplate" Value="{StaticResource TemplateB}" />
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </ContentControl.Style>
</ContentControl>

A better alternative is to use DataTemplates for different Items. Then you just set your Content="{Binding SelectedItem}" and WPF will resolve the correct DataTemplate to use. I just showed the above example first because it can be used to base your Template off a Property of SelectedItem