本文實例講述了js實現類似jquery裡animate動畫效果的方法。分享給大家供大家參考。具體分析如下:
該實例可實現鼠標移上,先寬度變化,再高度變化,最後透明度變化,鼠標移出,再依次變回去的效果。
要點一:
startrun(obj,attr,target,fn) box.onmouseover = function(){ startrun(box,"width",200,function(){ startrun(box,"height",200,function(){ startrun(box,"opacity","100") }); }); }
如上面,函數也可以做為參數使用,就可以達到先執行某個動作,再執行某個動作的效果了。
要點二:
if(cur == target){ clearInterval(obj.timer); if(fn){ fn(); } }
當運動到達目標點,關閉定時器,然後就可以執行新的函數了。
最後,上代碼:
<!DOCTYPE html> <html> <head> <meta charset="gb2312" /> <title>無標題文檔</title> <style> <!-- body{margin:0; padding:0; font:12px/1.5 arial;} #box{width:100px; height:100px; position:absolute; background:#06c; left:0;filter:alpha(opacity=30); opacity:0.3;} --> </style> <script> <!-- function getstyle(obj,name){ if(obj.currentStyle){ return obj.currentStyle[name]; }else{ return getComputedStyle(obj,false)[name]; } } window.onload = function(){ var box = document.getElementById("box"); box.onmouseover = function(){ startrun(box,"width",200,function(){ startrun(box,"height",200,function(){ startrun(box,"opacity","100") }); }); } box.onmouseout = function(){ startrun(box,"height",100,function(){ startrun(box,"width",100,function(){ startrun(box,"opacity","30"); }); }); } } function startrun(obj,attr,target,fn){ 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); if(fn){ fn(); } }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) } //--> </script> </head> <body> <div id="box"> </div> </body> </html>
希望本文所述對大家的javascript程序設計有所幫助。