SoFunction
Updated on 2025-04-03

Getting started with javascript · Image object (refresh-transformed pictures) \ scroll image


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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http:///TR/xhtml1/DTD/">
<html xmlns="http:///1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>Image Object</title>
<script language="javascript">
<!--
//The book says that this way you can pre-cache the image objects, which is actually a scam. Below is a very large picture I specially prepared
    img1=new Image(300,400)
    ="/test/view/"
    img2=new Image(300,400)
    ="/test/view/"
    img3=new Image(300,400)
    ="/test/view/"
    img4=new Image(300,400)
    ="/test/view/"
function img(s){//Call the function according to the value passed by the drop-down menu, that is, the selected item is called
im=("select1").options[s].value;//Get the value of the selected item
("img").src=eval(im+".src")//Use the eval() function to reference the src value of the object and assign it to the picture on the page
}
//The following is automatically generated by DW, so it is a bit bad and I am too lazy to read. I'm troublesome. Here are what I wrote in my own reference book below
function MM_preloadImages() { //v3.0
  var d=document; if(){ if(!d.MM_p) d.MM_p=new Array();
    var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<; i++)
    if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
}

function MM_findObj(n, d) { //v4.01
  var p,i,x;  if(!d) d=document; if((p=("?"))>0&&) {
    d=[(p+1)].document; n=(0,p);}
  if(!(x=d[n])&&) x=[n]; for (i=0;!x&&i<;i++) x=[i][n];
  for(i=0;!x&&&&i<;i++) x=MM_findObj(n,[i].document);
  if(!x && ) x=(n); return x;
}

function MM_nbGroup(event, grpName) { //v6.0
  var i,img,nbArr,args=MM_nbGroup.arguments;
  if (event == "init" &&  > 2) {
    if ((img = MM_findObj(args[2])) != null && !img.MM_init) {
      img.MM_init = true; img.MM_up = args[3]; img.MM_dn = ;
      if ((nbArr = document[grpName]) == null) nbArr = document[grpName] = new Array();
      nbArr[] = img;
      for (i=4; i < -1; i+=2) if ((img = MM_findObj(args[i])) != null) {
        if (!img.MM_up) img.MM_up = ;
         = img.MM_dn = args[i+1];
        nbArr[] = img;
    } }
  } else if (event == "over") {
    document.MM_nbOver = nbArr = new Array();
    for (i=1; i < -1; i+=3) if ((img = MM_findObj(args[i])) != null) {
      if (!img.MM_up) img.MM_up = ;
       = (img.MM_dn && args[i+2]) ? args[i+2] : ((args[i+1])? args[i+1] : img.MM_up);
      nbArr[] = img;
    }
  } else if (event == "out" ) {
    for (i=0; i < document.MM_nbOver.length; i++) {
      img = document.MM_nbOver[i];  = (img.MM_dn) ? img.MM_dn : img.MM_up; }
  } else if (event == "down") {
    nbArr = document[grpName];
    if (nbArr)
      for (i=0; i < ; i++) { img=nbArr[i];  = img.MM_up; img.MM_dn = 0; }
    document[grpName] = nbArr = new Array();
    for (i=2; i < -1; i+=2) if ((img = MM_findObj(args[i])) != null) {
      if (!img.MM_up) img.MM_up = ;
       = img.MM_dn = (args[i+1])? args[i+1] : img.MM_up;
      nbArr[] = img;
  } }
}
//-->
</script>
</head>

<body onload="MM_preloadImages('img/','img/','img/')">

<p><strong>Demo 1: No refresh transformation picture (a bit crooked)</strong></p>
<p>
  <select name="select1" onchange="img()">
    <option value="img1">1</option>
    <option value="img2">2</option>
    <option value="img3">3</option>
    <option value="img4">4</option>
  </select>
  <input type="image" name="img" src="img/" />
</p>
<p><strong>Demo 2: Mouse triggers image transformation (the written name seems to be called image scrolling)</strong></p>
<p>
<script language="javascript">
//First create two arrays, one in the on state and the other in the off state
//Arrays use strings as indexing, for the first purpose, for easy identification, and for the second purpose, there will be no conflict during code operation.
    offimg=new Array()
    offimg["play"]=new Image(60,50)
    offimg["stop"]=new Image(60,50)
    offimg["pause"]=new Image(60,50)
    offimg["rewind"]=new Image(66,55)
//Assignment
    offimg["play"].src="img/"
    offimg["stop"].src="img/"
    offimg["pause"].src="img/"
    offimg["rewind"].src="img/"
//The second array
    onimg=new Array()
    onimg["play"]=new Image(60,50)
    onimg["stop"]=new Image(60,50)
    onimg["pause"]=new Image(60,50)
    onimg["rewind"]=new Image(66,55)
//Assignment
    onimg["play"].src="img/"
    onimg["stop"].src="img/"
    onimg["pause"].src="img/"
    onimg["rewind"].src="img/"
    function on(imgname){
if(){//Determine whether the browser can process image objects
[imgname].src=onimg[imgname].src// Assign the src value of the corresponding image object to the picture
        }
    }
    function off(imgname){
if(){//Determine whether the browser can process image objects
[imgname].src=offimg[imgname].src// Assign the src value of the corresponding image object to the picture
        }
    }
function setmsg(msg){//Change status bar prompt
        =msg;
        return true;
    }
</script>
<table width="591" border="1">
  <tr>
    <td width="169"><table border="0" cellpadding="0" cellspacing="0">
      <tr>
<td><a href="" target="_top" onclick="MM_nbGroup('down','group1','Blogs','img/',1)" onmouseover="MM_nbGroup('over','Blogs','img/',1)" onmouseout="MM_nbGroup('over','Blogs','img/','img/',1)" onmouseout="MM_nbGroup('out')"><img src="img/" alt="Tian Hongchuan Blog" name="Blogs" width="80" height="120" border="0"  onload="" //</a></td>
      </tr>
    </table>
<p><a href="">The above is made by DW<br />
It is preloaded with pictures</a></p></td>
    <td width="406">
<a href=""><img src="img/" width="80" height="120" border="0" name="play" onMouseOver="on('play');return setmsg('My Tutorial Blog --> ')" onmouseout="off('play');return setmsg('');" //</a>

<a href="/thcjp/category/"><img src="img/" width="80" height="120" border="0" name="stop" onmouseover="on('stop');return setmsg('Tianhong Chuan's Blog's JS Introduction Series Tutorial--> /thcjp/category/')" onmouseout="off('stop');return setmsg('')"/></a>

<a href="/thcjp/category/"><img src="img/" width="80" height="120" border="0" name="pause" onmouseover="on('pause');return setmsg('VS2005 Control Series Tutorial /thcjp/category/')" onmouseout="off('pause');return setmsg('')"/></a>

<a href=""><img src="img/" width="80" height="120" border="0" name="rewind" onmouseover="on('rewind');return setmsg('ajax series video tutorial --> ')" onmouseout="off('rewind');return setmsg('');" //</a></td>
  </tr>
</table>
</body>
</html>