mozRequestFullScreen（）; 不工作 为什么？

Question

I have:

function doit()
{
    document.getElementById('id1').mozRequestFullScreen();
}

But it doesn't work. Though it does for this site :

jsFiddle here .

Why? (I'm using FireFox.)

Answer 1

JSFiddle results are displayed within an iframe. Unless this frame explicitly allows fullscreen by adding the mozallowfullscreen attribute it will silently fail:

https://developer.mozilla.org/en-US/docs/HTML/Element/iframe#attr-mozallowfullscreen