DataTrigger Overflow exception

Question

How can this be an overflow exception...?

<DataTemplate x:Key="ElementTemplate">
            <StackPanel Orientation="Horizontal">
                <StackPanel.Style>
                    <Style TargetType="{x:Type StackPanel}">
                        <Style.Triggers>
                            <DataTrigger Binding="{Binding Converter={StaticResource TypeConv}}" Value="{x:Type models:GroupModel}">
                                <Setter Property="Margin" Value="5 0 0 0"></Setter>
                                <Setter Property="DataContext" Value="{Binding Model}"></Setter>
                            </DataTrigger>
                        </Style.Triggers>
                    </Style>
                </StackPanel.Style>
                <TextBlock Text="{Binding Name}"></TextBlock>
                ...
             <StackPanel/>
<DataTemplate/>

For the reason: this is a template (with at least 25 UI contros) that normally needs Model A as datatype. the DataTemplate is a ListvVew ItemTemplate. But the datatype can be of type Model B. Model B has a property called 'Model', which is of type Model A. So instead of copy pasting the whole block template and use style triggers or DataTemplate selectors, I just want to change the DataContext (from "{Binding}" to "{Binding Model}")

anyone has some suggestions, a solution?

Thx!

EDIT: the Converter returns the type of the incoming value (the data object itself). that way i can know when Model B is using the template and so to change the DataContext.

Answer 1

A work-around I would suggest to avoid possible recursion between setting the data context and triggering the DataTrigger:

Have both ModelA and ModelB implement a common interface called IListViewModel for example with a single property getter:

public interface IListViewModel
{
    ModelA Model {get;}
}

Then, ModelA's implementation will return this, while ModelB's implementation returns this.ModelA The DataTemplate simply binds to the .Modelof whichever view model it's given.