layui的layer.confirm获取按钮焦点

因为ayer.confirm的按钮并非采用button，而是a标签，所以获取按钮焦点获取不到，要采用别的方法，下面介绍在ie11中和ie8中不同的写法

在ie11中

layer.confirm('确定取消这个弹窗吗？',{btn: ['确定', '取消'],success:function(layero){//获取焦点var btn = layero[0].getElementsByClassName('layui-layer-btn')        [0].getElementsByTagName('A')[0];    btn.href = 'javascript:void(0)';btn.focus();},title:"提示"},function(index){layer.close(index);//你的操作});})

在ie8中不支持getElementsByClassName方法，我们需要对它做额外的处理

layer.confirm('确定取消这个弹窗吗？',{btn: ['确定', '取消'],success:function(layero){//获取焦点var btn = getElementsByClassName('layui-layer-btn')        [0].getElementsByTagName('A')[0];    btn.href = 'javascript:void(0)';btn.focus();},title:"提示"},function(index){layer.close(index);//你的操作});})

重写getElementsByClassName方法

var getElementsByClassName = function (searchClass, node,tag) {var result = [];node = node || document;tag = tag || "*";var classes = searchClass.split(" "),elements = (tag === "*" && node.all) ? node.all: node.getElementsByTagName(tag),patterns = [],current,match;var i = classes.length;while (--i >= 0) {patterns.push(new RegExp("(^|\\s)" + classes[i] + "(\\s|$)"));}var j = elements.length;while (--j >= 0) {current = elements[j];match = false;for (var k = 0,kl = patterns.length; k < kl; k++) {match = patterns[k].test(current.className);if (!match) break;}if (match) result.push(current);}return result;}

 后种方法是兼容的不怕麻烦的可直接采取后种方法