在页面中如何防止后退操作?

Question

如上.

Answer 1

if   ((event.keyCode==8)||(event.keyCode==116)                             
  {   
  event.keyCode=0;   
              
  event.returnValue=false;   
              
  }

Answer 2

 
//设置页面不缓存,防止后退
response.setHeader("Cache-Control", "no-store");
response.setHeader("Pragrma", "no-cache");
response.setDateHeader("Expires", 0); if (session.getAttribute("UserId") == null|| session.getAttribute("UserId") == "") {
response.sendRedirect("Index.jsp");
}