用html5(requestFullscreen) js实现点击一个按钮使浏览器全屏效果

项目中需要将后台浏览器的窗口全屏，也就是我们点击一个按钮要实现按F11全屏的效果。 在HTML5中,W3C制定了关于全屏的API，就可以实现全屏幕的效果，也可以让页面中的图片，视频等全屏目前只有google chrome 15 +, safri5.1+,firfox10+,IE11支持 
查看例子，一睹为快！

全屏：

var docElm = document.documentElement;
//W3C
if (docElm.requestFullscreen) {
    docElm.requestFullscreen();
}
//FireFox
else if (docElm.mozRequestFullScreen) {
    docElm.mozRequestFullScreen();
}
//Chrome等
else if (docElm.webkitRequestFullScreen) {
    docElm.webkitRequestFullScreen();
}
//IE11
else if (elem.msRequestFullscreen) {
    elem.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();
}

　　事件监听：

document.addEventListener("fullscreenchange", function () {
fullscreenState.innerHTML = (document.fullscreen)? "" : "not ";}, false); 

document.addEventListener("mozfullscreenchange", function () {
fullscreenState.innerHTML = (document.mozFullScreen)? "" : "not ";}, false); 

document.addEventListener("webkitfullscreenchange", function () {
fullscreenState.innerHTML = (document.webkitIsFullScreen)? "" : "not ";}, false);

document.addEventListener("msfullscreenchange", function () {
fullscreenState.innerHTML = (document.msFullscreenElement)? "" : "not ";}, false);

　　全屏样式设置 ：

在浏览器全屏的使用我们还可以进行样式设置

代码如下:

html:-moz-full-screen {
    background: red;
}

html:-webkit-full-screen {
    background: red;
}

html:fullscreen {
    background: red;
}