1.WPF-Border边框--BorderBrush(边框颜色)--Padding(与内部元素的距离)--CornerRadius(圆角的半径)

<Window x:Class="StackPanel和border.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
    <Border BorderBrush="Red" BorderThickness="4" Padding="6"  CornerRadius="88">
    <StackPanel Orientation="Horizontal">
        <Button Content="button1" ></Button>
    </StackPanel>
    </Border>
</Window>