WPF XAML DataGridTemplateColumn assign to two DataTemplate with conditional types

Struggling with the great WPF and XAML, I found lots of info, e.g. this SO question, on how to use multiple DataTemplates with a data type condition, but I don't know how to connect those to a DataGrid column.

For example, to display data from class Material differently from class Usage, each with a Value field, here are two DataTemplates as suggested by the post linked above:

    <Grid.Resources>
        <!-- Do NOT set the x:Key -->
        <DataTemplate DataType="{x:Type models:Material}">
            <TextBlock Text="{Binding Value}" 
                Foreground="White"
                Background="Gray"
            />
        </DataTemplate>
        <DataTemplate DataType="{x:Type models:Usage}">
            <TextBlock Text="{Binding Value}"  
                Foreground="White"
                Background="Brown"
            />
        </DataTemplate>

This should be used in a DataGrid like this:

<DataGridTemplateColumn CellTemplate="{StaticResource MyTemplate}">

The post I referenced above indicates that I should NOT use the Key property on the DataTemplates. If I would, the Key should be unique, hence different on each DataTemplates, while BOTH templates should connect to the same DataGrid Column.

I have not found an element to group several DataTemplates in order to give them a collective resource name.

I am also seeing examples with in code-behind a C# class implementing a DataTemplateSelector, but that would be contrary to the DataType property in XAML to do the selection.

I could not yet find an XAML example showing the solution to this problem. Any help is greatly appreciated.

Since you are using the type to bind to the DataTemplate via resouces, you just need to supply an empty element to relay that binding. In this case I used a ContentControl, but pretty much any other content control element will work (i.e. ContentPresenter, Button, etc).

I think the example below generated what you are looking for:

<Grid.Resources>
    <DataTemplate DataType="{x:Type models:Usage}">
        <TextBlock Text="{Binding Value}" Foreground="White" Background="Gray" />
    </DataTemplate>
    <DataTemplate DataType="{x:Type models:Material}">
        <TextBlock Text="{Binding Value}" Foreground="White" Background="Brown" />
    </DataTemplate>
</Grid.Resources>

<DataGrid ItemsSource="{Binding Data}" AutoGenerateColumns="False" CanUserAddRows="False">
    <DataGrid.Columns>
        <DataGridTemplateColumn Header="Values">
            <DataGridTemplateColumn.CellTemplate>
                <DataTemplate>
                    <ContentControl Content="{Binding}" />
                </DataTemplate>
            </DataGridTemplateColumn.CellTemplate>
        </DataGridTemplateColumn>
    </DataGrid.Columns>
</DataGrid>

Result