我在WPF window里放了两个border，我想在点击button时，border的borderthickness改变，给我一段完整示例代码

好的，以下是一个简单的示例代码，点击按钮时可以改变两个Border的BorderThickness属性：

XAML代码：

<Window x:Class="WpfApp1.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">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="auto"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>
        <StackPanel Grid.Row="0" Orientation="Horizontal" HorizontalAlignment="Center">
            <Button x:Name="btnChangeBorderThickness" Content="Change Border Thickness" Click="btnChangeBorderThickness_Click"/>
        </StackPanel>
        <Grid Grid.Row="1" Margin="10">
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="*"/>
                <ColumnDefinition Width="*"/>
            </Grid.ColumnDefinitions>
            <Border x:Name="border1" BorderThickness="1" BorderBrush="Black" Margin="5">
                <TextBlock Text="Border 1"/>
            </Border>
            <Border x:Name="border2" BorderThickness="1" BorderBrush="Black" Grid.Column="1" Margin="5">
                <TextBlock Text="Border 2"/>
            </Border>
        </Grid>
    </Grid>
</Window>

C#代码：

using System.Windows;
using System.Windows.Media;

namespace WpfApp1
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private void btnChangeBorderThickness_Click(object sender, RoutedEventArgs e)
        {
            // 改变Border1的BorderThickness
            if (border1.BorderThickness.Equals(new Thickness(1)))
            {
                border1.BorderThickness = new Thickness(5);
            }
            else
            {
                border1.BorderThickness = new Thickness(1);
            }

            // 改变Border2的BorderThickness
            if (border2.BorderThickness.Equals(new Thickness(1)))
            {
                border2.BorderThickness = new Thickness(5);
            }
            else
            {
                border2.BorderThickness = new Thickness(1);
            }
        }
    }
}

在这个示例中，我们在Window中放置了一个StackPanel和一个Grid，StackPanel中有一个Button，Grid中有两个Border。当点击Button时，C#代码会检查两个Border的BorderThickness属性，如果当前值为1，则将其改为5，否则将其改为1。这个操作会实现一个简单的切换效果。