定时器的使用

定时器的打开

//间隔持续型setInterval(show,1000);//延时一次型setTimeout(show,1000);

定时器的关闭

oBtn1.onclick=function (){Timer = setInterval(function (){alert('a');},1000);}oBtn2.onclick=function(){clearInterval(Timer);}

定时器的应用

数码时钟，Date对象的使用

function toDou(n){if(n<10){return '0'+n;}if(n>10){return ''+n;}}window.onload=function(){var aImg = document.getElementsByTagName('img');function Timer(){var oDate = new Date();var str = toDou(oDate.getHours()) + toDou(oDate.getMinutes()) + toDou(oDate.getSeconds());for(var i=0;i<aImg.length;i++){aImg[i].src='img/'+str.charAt(i)+'.png';}}setInterval(Timer,1000);Timer();}

延时提示框 （QQ资料），简化代码

window.onload=function(){oDiv1 = document.getElementById('div1');oDiv2 = document.getElementById('div2');oDiv2.onmouseover=oDiv1.onmouseover=function(){clearTimeout(timer);oDiv2.style.display='block';};oDiv2.onmouseout=oDiv1.onmouseout=function(){timer = setTimeout(function(){oDiv2.style.display='none';},1000)};};

无缝滚动基础

window.onload=function (){var oDiv = document.getElementById('div1');var oUl = oDiv.getElementsByTagName('ul')[0];var aLi = oUl.getElementsByTagName('li');var speed =-2;//UL里面的内容加一倍oUl.innerHTML=oUl.innerHTML+oUl.innerHTML;oUl.style.width=aLi[0].offsetWidth*aLi.length+'px';//定时器功能,当UL的内容走到一半的时候再把它扯回来function move(){if(oUl.offsetLeft<-oUl.offsetWidth/2){oUl.style.left='0';}if(oUl.offsetLeft>0){oUl.style.left=-oUl.offsetWidth/2+'px';}oUl.style.left=oUl.offsetLeft+speed+'px';}//使用定时器var Timer = setInterval(move,10);//鼠标进入滚动停止oDiv.onmouseover=function(){clearInterval(Timer);}////鼠标离开滚动开始oDiv.onmouseout=function(){Timer =setInterval(move,10);}//向左滚动document.getElementsByTagName('a')[0].onclick=function(){ speed = -2;};//向右滚动document.getElementsByTagName('a')[1].onclick=function(){speed = 2;};};