使用ContentPresenter，不使用ContentControl

参考： https://wpf.2000things.com/2017/04/06/1204-using-a-datatrigger-to-change-content-in-a-contentpresenter/

<Window.Resources>

    <DataTemplate x:Key="DefaultContent">

        <StackPanel>

            <TextBlock Margin="10" Text="Some default content here.."/>

            <TextBlock Margin="10" Text="Maybe show progress for operation"/>

        </StackPanel>

    </DataTemplate>

    <DataTemplate x:Key="AllDoneContent">

        <StackPanel>

            <TextBlock Margin="10" Text="** This is the ALL DONE content..."

                       Foreground="Green"/>

            <TextBlock Margin="10" Text="Put anything you like here"/>

            <Button Margin="10" Content="Click Me" HorizontalAlignment="Left"/>

        </StackPanel>

    </DataTemplate>

    <Style x:Key="MyContentStyle" TargetType="ContentPresenter">

        <Setter Property="ContentTemplate" Value="{StaticResource DefaultContent}"/>

        <Style.Triggers>

            <DataTrigger Binding="{Binding JobDone}" Value="True">

                <Setter Property="ContentTemplate" Value="{StaticResource AllDoneContent}"/>

            </DataTrigger>

        </Style.Triggers>

    </Style>

</Window.Resources>

<Grid Margin="10">

    <Grid.RowDefinitions>

        <RowDefinition Height="*"/>

        <RowDefinition Height="Auto"/>

        <RowDefinition Height="*"/>

    </Grid.RowDefinitions>

    <ContentPresenter Grid.Row="0" Style="{StaticResource MyContentStyle}" Content="{Binding}"/>

    <Separator Grid.Row="1"/>

    <CheckBox Grid.Row="2" Margin="10" Content="Mark job done" IsChecked="{Binding JobDone}"/>

</Grid>

ContentControl通过DataTrigger进行切换模板时，原来绑定的模板会引发DataContext事件