What is needed to have a designable Templated Custom Control.

Question

I try to create a custom control with 3 designable areas. After 2 weeks of unsucessfull digging around with reflector i startet a little test...

I created a custom control derived from Control with exact one property called "Content" as default property, created a Template, a PlacementAdapter and a ParentAdapter...

It works well, i can drag content in and out of the control in VS designer. Then i added a Border to my Template like this:

    <Style TargetType="{x:Type local:MyContentControl}">
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type local:MyContentControl}">
                    <Border Background="{TemplateBinding Background}"
                            BorderBrush="{TemplateBinding BorderBrush}"
                            BorderThickness="{TemplateBinding BorderThickness}">
                        <Grid>
                            <Grid.ColumnDefinitions>
                                <ColumnDefinition Width="*"/>
                                <ColumnDefinition Width="20"/>
                            </Grid.ColumnDefinitions>
                            <Border
                                BorderBrush="Red"
                                BorderThickness="1"
				Grid.Column="1"
                                />
                            <ContentPresenter
                                />
                        </Grid>
                    </Border>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

From this time on it is not posible to select "MyControl" by a click in designer or to drag content into the Control.

After reading msdn's Extensibility Documentation i have no clue why this happens or how to enable selection and draging for a such template.

Emmo

Answer 1

And the Answer is:

Its imposible!

Deep in the MS.Internal Drag & Drop- and Selection-code are "some" checks for ContentControl and HeaderedItemsControl. that makes all attempts to have a Control with more than 2 "Designable" areas a joke.

Emmo