IE8及更早的版本不支持 addEventListener()函数,因此需要一个标准的函数将这些差异性做封装:

1 function addListener(target, type, handler) {2     if (target.addEventListener) {3         target.addEventListener(type, handler, false);4     } else if (target.attachEvent) {5         target.attachEvent("on" + type, handler);6     } else {7         target["on" + type] = handler;8     }9 }

使用 addListener()函数:

1 function doSomeThing() {2     // 代码3 }4 var btn = document.getElementById("action-btn");5 addListener(btn, "click", doSomeTing);