C#事件中关于sender的用法解读

private void Button_Click(object sender, RoutedEventArgs e)
{
    //……blahblahblah
}

private void Button_Click(object sender, RoutedEventArgs e)
{
    Button btn = (Button)sender;
    btn.Content = "我被点击了";
}

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 WPFLittleTips
{
    /// 
    /// MainWindow.xaml 的交互逻辑
    /// 
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }
 
        private void btnObj1_Click(object sender, RoutedEventArgs e)
        {
            Button btn = (Button)sender;
            if(btn == btnObj1)
            {
                MessageBox.Show("Btn1 被点击了");
            }
            else
            {
                MessageBox.Show("Btn2 被点击了");
            }
        }
    }
}