问题
I'm working in a framed environment, and trying to tell if the frame on which some javascript code executes is the top frame (the one that contains the rest).
Up until now I was trying to check it with
window.parent != null
but it always returns false, like in this simple example.
<html>
<head>
<script>
alert(parent == null);
</script>
</head>
<body>
<h1>OH YEAH!</h1>
</body>
</html>
Is there a way to do this? I doesn't have to be portable, right now I'm looking for the IE6 solution.
回答1:
I found this pdf to be very useful: http://seclab.stanford.edu/websec/framebusting/framebust.pdf
In short, if this is too long to read, this is what they ultimately propose :
<style>
html { display :none; }
</style>
<script>
if(self==top){
document.documentElement.style.display = 'block';
}else{
top.location=self.location;
}
</script>
You will find many other means to do this in this pdf and each means' pro and cons. Obviously, on browsers without JavaScript, this solution could be painful ;)
回答2:
self === top
should return true if executed in the topmost frameset, false otherwise.
回答3:
You can check if top.frames.length == 0.
来源：https://stackoverflow.com/questions/3135380/how-to-tell-if-current-frame-is-parent