Question

is it possible to insert some UserControl into ContentControl?

but I need to dynamically decide which UserControl I need to insert (like with DataTemplateSelector).

Answer 1

Yes, you can place any object in ContentControl.Content, however depending on what determines what UserControl you want, there are multiple ways of accomplishing this.

My personal favorite is to go with a DataTrigger that determines the ContentControl.ContentTemplate based on some condition

Here’s an example that bases the ContentControl.Content on a ComboBox’s selected value:

<DataTemplate DataType="{x:Type DefaultTemplate}">
    <TextBlock Text="Nothing Selected" />
</DataTemplate>
<DataTemplate DataType="{x:Type TemplateA}">
    <localControls:UserControlA />
</DataTemplate>
<DataTemplate DataType="{x:Type TemplateB}">
    <localControls:UserControlB />
</DataTemplate>

<Style TargetType="{x:Type ContentControl}" x:Key="MyContentControlStyle">
    <Setter Property="ContentTemplate" Value="{StaticResource DefaultTemplate}" />
    <Style.Triggers>
        <DataTrigger Binding="{Binding ElementName=MyComboBox, Path=SelectedValue}" Value="A">
            <Setter Property="ContentTemplate" Value="{StaticResource TemplateA}" />
        </DataTrigger>
        <DataTrigger Binding="{Binding ElementName=MyComboBox, Path=SelectedValue}" Value="B">
            <Setter Property="ContentTemplate" Value="{StaticResource TemplateB}" />
        </DataTrigger>
    </Style.Triggers>
</Style>