1.关联按钮上的Key事件
  
          按钮上的keypress，keydown，keyup事件随便一个即可
          


  private void textBox1_KeyDown(object sender, KeyEventArgs e)
 {
     
     if (e.KeyCode == Keys.Enter)
     {
         this.textBox2.Focus();
     }
 }

2.窗体上的事件

   private void textBox2_KeyPress(object sender, KeyPressEventArgs e)
   {
       if(e.KeyChar==(char)Keys.Enter)
       {
           this.button1_Click(sender, e);
       }
   }

可以设置这两个,窗体登录和退出,将他们两个设置成enter和Ese

private void Form2_Load(object sender, EventArgs e)

        {

            Form_Login.AcceptButton = btnLogin;//btnLogin是登陆按钮

            Form_Login.CancelButton = btnExit;//btnExit是退出按钮

        }