iframe 全屏

<iframe id="myIframe" src="https://example.com" width="100%" height="100%"></iframe>

html, body {
    margin: 0;
    padding: 0;
    height: 100%;
    overflow: hidden;
}

#myIframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

function enterFullScreen(iframe) {
    if (iframe.requestFullscreen) {
        iframe.requestFullscreen();
    } else if (iframe.mozRequestFullScreen) { // Firefox
        iframe.mozRequestFullScreen();
    } else if (iframe.webkitRequestFullscreen) { // Chrome, Safari and Opera
        iframe.webkitRequestFullscreen();
    } else if (iframe.msRequestFullscreen) { // IE/Edge
        iframe.msRequestFullscreen();
    }
}

document.getElementById('myIframe').addEventListener('click', function() {
    enterFullScreen(this);
});