如何在wpf中绘制某个形状并将其放置在文本框内的文本旁边

<Window x:Class="WpfApp.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="WPF Shape" Height="450" Width="800">
    <Grid>
        <TextBox x:Name="textBox" Width="200" Height="30" Text="Hello World!" />
        <Canvas x:Name="canvas" Margin="10" />
    </Grid>
</Window>

using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Shapes;

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

            // 创建一个矩形形状
            Rectangle rectangle = new Rectangle();
            rectangle.Width = 50;
            rectangle.Height = 50;
            rectangle.Fill = Brushes.Red;

            // 设置矩形的位置
            Canvas.SetLeft(rectangle, textBox.ActualWidth + 10);
            Canvas.SetTop(rectangle, textBox.ActualHeight / 2 - rectangle.Height / 2);

            // 将矩形添加到Canvas控件中
            canvas.Children.Add(rectangle);
        }
    }
}