如何在WPF中创建圆角窗体？

<Application.Resources>
    <ResourceDictionary>
        <Style x:Key="RoundedWindowStyle" TargetType="{x:Type Window}">
            <Setter Property="Background" Value="LightBlue"/>
            <Setter Property="BorderBrush" Value="Black"/>
            <Setter Property="BorderThickness" Value="2"/>
            <Setter Property="WindowStyle" Value="None"/>
            <Setter Property="AllowsTransparency" Value="True"/>
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type Window}">
                        <Border BorderBrush="{TemplateBinding BorderBrush}"
                                BorderThickness="{TemplateBinding BorderThickness}"
                                Background="{TemplateBinding Background}">
                            <Grid>
                                <AdornerDecorator>
                                    <ContentPresenter/>
                                </AdornerDecorator>
                                <Rectangle RadiusX="20" RadiusY="20" Fill="White" Margin="5"/>
                            </Grid>
                        </Border>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
    </ResourceDictionary>
</Application.Resources>

<Window x:Class="YourNamespace.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="450" Width="800"
        Style="{StaticResource RoundedWindowStyle}">
    <Grid>
        <!-- Your content here -->
    </Grid>
</Window>