this.AcceptButton = button1的用法：

 using System;
 using System.Collections.Generic;
 using System.ComponentModel;
 using System.Data;
 using System.Drawing;
 using System.Text;
 using System.Windows.Forms;

 namespace Test02
 {
     public partial class Form1 : Form
     {
         public Form1()
         {
             InitializeComponent();
         }

         private void Form1_Load(object sender, EventArgs e)
         {
             this.AcceptButton = button1;
         }

         private void button1_Click(object sender, EventArgs e)
         {
             MessageBox.Show("引发了接受按钮1");
         }

     }
 }

this.AcceptButton = button1;只是能对选中的按钮进行操作，并不能对未选中的进行操作。