let docElm =document.documentElement //全屏代码
if (docElm.requestFullscreen) {
docElm.requestFullscreen();
} else if (docElm.mozRequestFullScreen) {
docElm.mozRequestFullScreen();
} else if (docElm.webkitRequestFullScreen) {
docElm.webkitRequestFullScreen();
} else if (docElm.msRequestFullscreen) {
docElm.msRequestFullscreen();
}
//退出全屏
if (document.exitFullscreen) {
document.exitFullscreen();
} else if (document.mozCancelFullScreen) {
document.mozCancelFullScreen();
} else if (document.webkitCancelFullScreen) {
document.webkitCancelFullScreen();
} else if (document.msExitFullscreen) {
document.msExitFullscreen();
}