本文實例講述了js實現同一頁面多個不同運動效果的方法。分享給大家供大家參考。具體分析如下：
要點一：
function getstyle(obj,name){if(obj.currentStyle){return obj.currentStyle[name];}else{return getComputedStyle(obj,false)[name];}}從樣式表中根據id和屬性名取值。
要點二：
if(attr == "opacity"){cur = Math.round(parseFloat(getstyle(obj,attr))*100);}else{cur = parseInt(getstyle(obj,attr));}如果設置的是透明度的值，因為有可能會是小數點，所以需要用parseFloat，然后有可能會有小數，用round方法四舍五入取整。
如果設置的非透明度值，用parseInt，可以只取數值部分
其它的注意點，前面幾篇都有提到，此處不再贅述。
最后，上代碼：
<!DOCTYPE html><html><head><meta charset="utf-8" /><title>無標題文檔</title><style>body,ul,li{margin:0; padding:0;}#runs li{width:80px; height:80px; background:#06c;list-style:none; margin:10px; border:1px solid #000;filter:alpha(opacity=30); opacity:0.3;}</style><script>window.onload = function(){ var runs = document.getElementById("runs"); var runs_li = runs.getElementsByTagName("li"); runs_li[0].onmouseover = function(){ startrun(this,"width",300); } runs_li[0].onmouseout = function(){ startrun(this,"width",80); } runs_li[1].onmouseover = function(){ startrun(this,"height",300); } runs_li[1].onmouseout = function(){ startrun(this,"height",80); } runs_li[2].onmouseover = function(){ startrun(this,"fontSize",50); } runs_li[2].onmouseout = function(){ startrun(this,"fontSize",14); } runs_li[3].onmouseover = function(){ startrun(this,"opacity",100); } runs_li[3].onmouseout = function(){ startrun(this,"opacity",30); }}function startrun(obj,attr,target){ clearInterval(obj.timer); obj.timer = setInterval(function(){ var cur = 0; if(attr == "opacity"){ cur = Math.round(parseFloat(getstyle(obj,attr))*100); }else{ cur = parseInt(getstyle(obj,attr)); } var speed = (target - cur)/8; speed = speed>0?Math.ceil(speed):Math.floor(speed); if(cur == target){ clearInterval(obj.timer); }else{ if(attr == "opacity"){ obj.style.filter='alpha(opacity='+(cur+speed)+')'; obj.style.opacity=(cur+speed)/100; }else{ obj.style[attr] = cur+speed+"px"; } } },30);}function getstyle(obj,name){ if(obj.currentStyle){ return obj.currentStyle[name]; }else{ return getComputedStyle(obj,false)[name]; }}</script></head><body><ul id="runs"> <li style="top:0">1</li> <li style="top:90px;">2</li> <li style="top:180px;">3</li> <li style="top:270px;">4</li></ul></body></html>希望本文所述對大家的javascript程序設計有所幫助。
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