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问题:

I have a jsp page with frames

<%@ include file="/includes/taglibs.jsp"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Frameset//EN" "http://www.w3.org/TR/html4/frameset.dtd">
<html>
  <head>
  <title>Welcome</title>
    <script type="text/javascript" src="/js/jquery-1.3.2.min.js"></script>
    <script type="text/javascript">
        $(document).ready(function(){
            $(this).keydown(function(e) {
                if(e.keyCode==27){
                    alert("escape pressed");
                    e.preventDefault();
                }
          });       
        }   
        );  
      </script> 
  </head>
      <frameset rows="42,*" frameborder="0" framespacing="0" id="framest">
          <frame src="/xyz/abc.html" scrolling="no" name="frame1"/>
          <frame src="/xyz/init.html" scrolling="no" name="frame2"/>
      </frameset>
</html>

I am trying to capture escape key press. But this doesn't seem to work. On each individual frame html if I write the same code of capturing , it works perfectly fine.

What changes should I make in the code above so that I would write the keydown code just once which enables me to capture keydown on anywhere on page on any frame.

回答1:

Remember a frame is a completely new HTML page with a whole separate DOM, so jQuery doesn't include it in your bindings.

So you will need to bind to those documents also:

function keyDownHandler(e) {
    if(e.keyCode==27){
        alert("escape pressed");
        e.preventDefault();
    }
}

for (var id in window.parent.frames)
    $(window.parent.frames[id].document).keydown(keyDownHandler);
$(document).keydown(keyDownHandler);

If the above doesn't work for you because of the `id`:

for (var i = 0; i < window.parent.frames.length; i ++) {
   var frame = window.parent.frames[i].document;
   frame.addEventListener("keydown",keyDownHandler, true);
}

If you want to reference all frames, from the top level

for (var i = 0; i < top.window.frames.length; i ++) {
   var frame = top.window.frames[i].document;
   frame.addEventListener("keydown",keyDownHandler, true);
}