WPF多窗口

Mainwindow.xaml

<Window x:Class="WPF多窗口.MainWindow"        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"        Title="主窗口" Height="388.889" Width="581.322">    <Grid Margin="0,0,2,-4">        <Button x:Name="ButtonNew" Content="显示新窗口" HorizontalAlignment="Left" Margin="336,104,0,0" VerticalAlignment="Top" Width="170" Click="ButtonNew_Click"/>        <Button x:Name="ButtonClose" Content="关闭全部附属窗口" HorizontalAlignment="Left" Margin="336,175,0,0" VerticalAlignment="Top" Width="170" Click="ButtonClose_Click"/>        <Button x:Name="ButtonExit" Content="结束程序运行" HorizontalAlignment="Left" Margin="336,245,0,0" VerticalAlignment="Top" Width="170" Click="ButtonExit_Click"/>    </Grid></Window>

MainWindow.xaml.cs

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows;using System.Windows.Controls;using System.Windows.Data;using System.Windows.Documents;using System.Windows.Input;using System.Windows.Media;using System.Windows.Media.Imaging;using System.Windows.Navigation;using System.Windows.Shapes;namespace WPF多窗口{    /// <summary>    /// MainWindow.xaml 的交互逻辑    /// </summary>    public partial class MainWindow : Window    {        private int windowCount;        private int left;        private int top;        public MainWindow()        {            InitializeComponent();            windowCount = 0;            left = 300;            top = 300;        }        private void ButtonNew_Click(object sender, RoutedEventArgs e)        {            Window win = new Window();            windowCount++; left += 30; top += 30;            win.Title = "附属窗口" + windowCount.ToString();            win.Height = 200; win.Width = 328;            win.Left = left; win.Top = top;            win.Owner = this;            win.ShowActivated = false;            win.Show();        }        private void ButtonClose_Click(object sender, RoutedEventArgs e)        {            foreach (Window win in this.OwnedWindows)                win.Close();        }        private void ButtonExit_Click(object sender, RoutedEventArgs e)        {            App.Current.Shutdown();        }    }}