onload自定義函式的六種寫法
阿新 • • 發佈:2019-02-11
第一種方法:
function addfunction(){
...
}
<body onload="addfunction()">
第二種方法:
window.onload = addfunction; function addfunction(){ ... }
第三種方法:
window.onload = function(){ firstFunction(); secondFunction(); }
第四種方法:
function addLoadEvent(func) { var oldonload = window.onload; if (typeof window.onload != 'function') { window.onload = func; } else { window.onload = function() { oldonload(); func(); } } } addLoadEvent(addfunction);
第五種方法:
function addEvent(obj,EventName,callBack){//給物件新增事件 if(obj.addEventListener){ obj.addEventListener(EventName,callBack,false); }else if(obj.attachEvent){//IE obj.attachEvent('on'+EventName,callBack); }else{ obj["on"+EventName]=callBack; } } function a(){ alert("a"); } function b(){ alert("b"); } addEvent(window,"load",a); addEvent(window,"load",b);
第六種方法:
// Please note: this file contains snippets for comparison // it is not self-contained or ready-to-use code as such function addLoadListener(fn) { if (typeof window.addEventListener != 'undefined') { window.addEventListener('load', fn, false); } else if (typeof document.addEventListener != 'undefined') { document.addEventListener('load', fn, false); } else if (typeof window.attachEvent != 'undefined') { window.attachEvent('onload', fn); } else { var oldfn = window.onload; if (typeof window.onload != 'function') { window.onload = fn; } else { window.onload = function() { oldfn(); fn(); }; } } }