本文实例为大家分享了JavaScript仿flash遮罩动画的具体实现代码，供大家参考，具体内容如下
<!DOCTYPE html><html><head><meta charset="utf-8"><title>仿flash遮罩动画</title><meta name="keywords" content=""><meta name="description" content=""><script charset="utf-8" src="jquery.js"></script><style media="screen">body{margin:0;}#banner{position:relative;width:858px;height:238px;overflow:hidden;}</style></head><body><div id="banner"> <a href="javascript:void(0);"><img src="1.jpg"/></a></div><script type="text/javascript">function setMaskingAnimation(container,width,height,time,pixel,color){ var __left=mtRand(parseInt(width*0.25),parseInt(width*0.75)); var __top=mtRand(parseInt(height*0.25),parseInt(height*0.75)); if(width>=height){ var widthSpeed=parseInt((width/height)*10); var heightSpeed=10; var __width=widthSpeed; var __height=heightSpeed; } else{ var widthSpeed=10; var heightSpeed=parseInt((height/width)*10); var __width=widthSpeed; var __height=heightSpeed; } var hander; // function getPosition(_width,_height,_left,_top){ var div1={ "width":_left, "height":_top, "left":0, "top":0 }; var div2={ "width":_width, "height":_top, "left":_left, "top":0 }; var div3={ "width":width-_left-_width, "height":_top, "left":_left+_width, "top":0 }; var div4={ "width":_left, "height":_height, "left":0, "top":_top }; var div5={ "width":_width, "height":_height, "left":_left, "top":_top }; var div6={ "width":width-_left-_width, "height":_height, "left":_left+_width, "top":_top }; var div7={ "width":_left, "height":height-_top-_height, "left":0, "top":_top+_height }; var div8={ "width":_width, "height":height-_top-_height, "left":_left, "top":_top+_height }; var div9={ "width":width-_left-_width, "height":height-_top-_height, "left":_left+_width, "top":_top+_height }; return { "div1":div1, "div2":div2, "div3":div3, "div4":div4, "div5":div5, "div6":div6, "div7":div7, "div8":div8, "div9":div9, }; } // function mtRand(n1,n2){ return parseInt(Math.random()*(n2-n1+1)+n1); } // function setDiv(i,position){ var has=$(container).find("div.mask"+i); if(has.length){ has.css("left",position.left); has.css("top",position.top); has.css("width",position.width); has.css("height",position.height); } else{ var html='<div style="position:absolute;left:{@left}px;top:{@top}px;width:{@width}px;height:{@height}px;background-color:{@backgroundColor};"></div>'; html=html.replace('{@i}',i); html=html.replace('{@left}',position.left); html=html.replace('{@top}',position.top); html=html.replace('{@width}',position.width); html=html.replace('{@height}',position.height); if(i==5){ html=html.replace('{@backgroundColor}',"transparent"); } else{ html=html.replace('{@backgroundColor}',color); } $(container).append(html); } } // function play(){ __width+=pixel*widthSpeed; __height+=pixel*heightSpeed; __left-=pixel*widthSpeed/2; __top-=pixel*heightSpeed/2; var position=getPosition(__width,__height,__left,__top); for(var i=1;i<=9;i++){ setDiv(i,position["div"+i]); } if(position.div1.width<=0 && position.div1.height<=0 && position.div9.width<=0 && position.div9.height<=0){ window.clearInterval(hander); $(container).find("div.mask").remove(); } } // hander=window.setInterval(play,time);} $(function(){ setMaskingAnimation("#banner",858,238,100,2,"#ff0000"); //第4个参数和第5个参数分别设置20和2效果会比较好 //第5个参数必须是偶数});</script></body></html>以上就是本文的全部内容，希望对大家学习JavaScript程序设计有所帮助。