20.Xaml GroupBox控件 ----＞带标题的内容控件

1.运行效果

2.运行源码

a.Xaml源码

<Window x:Class="testView.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/20