js之切换全屏和退出全屏实现

应用场景:
比如很多网页游戏全屏之类的，或者是网上看小说等。

核心代码:

//控制全屏

function enterfullscreen() { //进入全屏

    $("#fullscreen").html("退出全屏");

    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();

    }

}

function exitfullscreen() { //退出全屏

    $("#fullscreen").html("切换全屏");

    if(document.exitFullscreen) {

        document.exitFullscreen();

    } else if(document.mozCancelFullScreen) {

        document.mozCancelFullScreen();

    } else if(document.webkitCancelFullScreen) {

        document.webkitCancelFullScreen();

    } else if(document.msExitFullscreen) {

        document.msExitFullscreen();

    }

}

var a = ;

$('#fullscreen').on('click', function() {

    a++;

    a %  ==  ? enterfullscreen() : exitfullscreen();

})

前端代码:

<a type="button" id="fullscreen" class="btn btn-default visible-lg visible-md"><i class="fa fa-refresh" aria-hidden="true"></i> 切换全屏</a>