如何使用JavaScript访问iframe #document

Question

I have this frame i cannot access,from initial inspection of the frame i noticed the frame contained a #document then i wrote a code to access the frame.

$body = document.body;    
$body.children[3];    
$yo = $body.children[3];
$yo.children[0];    
$next = $yo.children[0];    
$next.children[3];    
$plus = $next.children[3];    
$plus.children[0];    
$star = $plus.children[0];    
$star.children[0];    
$staragain = $star.children[0];    
$staragain.children[1];    
$nextstar = $staragain.children[1];    
$nextstar.children[1];    
$afternext = $nextstar.children[1];    
$afternext.contentWindow;        

The last line returns restricted,and
iframe.contentDocument returns null . Then i tried to access the frame document which is a #document with iframe.children[0] it returned undefined ,then i left the array open but nothing happened.All codes i run on the frame returns undefined how do i access this frame #document? yoyoyo .

Answer 1

iframe.contentWindow.document但仅在原点相同的情况下（由于同源政策） 。