DOM事件探秘-QQ拖曳效果
function getByName(clsName,parent) {
? var oParent = parent?document.getElementById(parent):document,
? ? ? eles = [],
? ? ? elements = oParent.getElementsByTagName('*');
? for (var i=0;i<elements.length;i++) {
? ? ? if (elements[i].className == ?clsName) {
? ? ? ? eles.push(elements[i]);
? ? ? }
? ? ? return eles;
? }
}
window.onload = drag;
function drag() {
? var oTitle = getByName('login_logo_webqq','loginPanel')[0];
? oTitle.onmousedown = fnDown;
}
function fnDown() {
? var oDrag = document.getElementById('loginPanel')
? document.onmousemove = function(event){
? ? event = event || window.event;
? ? oDrag.style.left = event.clientX+'px';
? ? oDrag.style.top = event.clientY+'px';
? }
}
DOM時間探秘里邊照著視頻打的，對了一遍沒找到問題……控制臺報錯Cannot set property 'onmousedown' of undefined，不知道啥原因……望解答，謝謝！
2016-11-20
應該在 for 循環外
??for?(var?i=0;i<elements.length;i++)?{ ??????if?(elements[i].className?==??clsName)?{ ????????eles.push(elements[i]); ??????} ??} ??return?eles;