视频 全屏

function requestFullScreen() {
    let de = video;
    if (de.requestFullscreen) {
        de.requestFullscreen();
    } else if (de.mozRequestFullScreen) {
        de.mozRequestFullScreen();
    } else if (de.webkitRequestFullScreen) {
        de.webkitRequestFullScreen();
    }
}
//退出全屏
function exitFullscreen() {
    let de = document;
    if (de.exitFullscreen) {
        de.exitFullscreen();
    } else if (de.mozCancelFullScreen) {
        de.mozCancelFullScreen();
    } else if (de.webkitCancelFullScreen) {
        de.webkitCancelFullScreen();
    }
}