图片的左右移动，js动画效果实现代码

<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=gb2312"> <title>图片的左右移动，动画效果的实现</title> <script LANGUAGE="JavaScript"><!-- step = 0; obj = new Image(); function anim(xp,xk,smer) { obj.style.left = x; x += step*smer; if (x>=(xk+xp)/2) { if (smer == 1) step--; else step++; } else { if (smer == 1) step++; else step--; } if (x >= xk) { x = xk; smer = -1; } if (x <= xp) { x = xp; smer = 1; } setTimeout('anim('+xp+','+xk+','+smer+')', 50); } function moveLR(objID,movingarea_width,c) { if (navigator.appName=="Netscape") window_width = window.innerWidth; else window_width = document.body.offsetWidth; obj = document.images[objID]; image_width = obj.width; x1 = obj.style.left; x = Number(x1.substring(0,x1.length-2)); if (c == 0) { if (movingarea_width == 0) { right_margin = window_width - image_width; anim(x,right_margin,1); } else { right_margin = x + movingarea_width - image_width; if (movingarea_width < x + image_width) window.alert("No space for moving!"); else anim(x,right_margin,1); } } else { if (movingarea_width == 0) right_margin = window_width - image_width; else { x = Math.round((window_width-movingarea_width)/2); right_margin = Math.round((window_width+movingarea_width)/2)-image_width; } anim(x,right_margin,1); } } //--></script> </head> <body> <img src="http://img.gxlcms.com//Uploads-s/new/2019-09-17-201917/logo.gif" name="picture" style="position: absolute; top: 70px; left: 30px;" BORDER="0"> <script LANGUAGE="JavaScript"><!-- setTimeout("moveLR('picture',300,1)",10); //--></script> </body> </html>
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