aistudio-wpf-diagram/AIStudio.Wpf.DiagramDesigner.Demo/ViewModels/CustomDesignerItemViewModel.xaml

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:dd="https://gitee.com/akwkevin/aistudio.-wpf.-diagram"
                    xmlns:viewmodel="clr-namespace:AIStudio.Wpf.DiagramDesigner.Demo.ViewModels">

    <dd:ColorBrushConverter x:Key="ColorBrushConverter" />

    <DataTemplate DataType="{x:Type viewmodel:CustomDesignerItemViewModel}">
        <Grid>
            <Border BorderThickness="1" Background="{Binding ColorViewModel.FillColor,Converter={StaticResource ColorBrushConverter}}" BorderBrush="{Binding ColorViewModel.LineColor,Converter={StaticResource ColorBrushConverter}}" >
                <Grid Margin="10">
                    <Grid.RowDefinitions>
                        <RowDefinition/>
                        <RowDefinition/>
                    </Grid.RowDefinitions>
                    <TextBlock HorizontalAlignment="Left" VerticalAlignment="Center" Text="Bot Answer"/>
                    <TextBox HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Grid.Row="1" Style="{StaticResource WaterTextBox}"/>
                </Grid>
            </Border>
        </Grid>
    </DataTemplate>
</ResourceDictionary>