如何在XAML中剥离字符串的第一个字符

<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="450" Width="800">
    <Grid>
        <TextBox x:Name="inputTextBox" Width="200" Height="30" Margin="10"/>
        <Button Content="Remove First Character" Width="150" Height="30" Margin="10,50,10,10" Click="Button_Click"/>
        <TextBlock x:Name="outputTextBlock" Width="200" Height="30" Margin="10,100,10,10"/>
    </Grid>
</Window>

using System;
using System.Windows;

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

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            string input = inputTextBox.Text;
            if (!string.IsNullOrEmpty(input))
            {
                string output = input.Substring(1);
                outputTextBlock.Text = output;
            }
        }
    }
}