<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>自制缩放</title>
<style>
#wrapper{
width: 500px;
margin: 0 auto;
position: relative;
}
#input{
position: absolute;
top: 0px;
}
input{
color:green;
background: white;
}
</style>
</head>
<body>
<div id="wrapper">
<div id="input">
<input type="button" value="放大" id="enlarge"><input type="button" value="缩小" id="narrow">
</div>
<img src="4.jpg" alt="this is a picture" id="myImage">
</div>
<script>
window.onload=function(){
var image=document.getElementById("myImage");
var largeButton=document.getElementById("enlarge");
largeButton.onclick=function(){
larger();
}
var maxWidth=image.width*2.5;
var maxHeight=image.height*2.5;
function larger(){
var endHeight=image.height*1.3;
var endWidth=image.width*1.3;
var largeTimer=setInterval(function(){
if(image.width<endWidth){
if(image.width<maxWidth){
image.width=image.width*1.03;
image.height=image.height*1.03;
}else{
alert("此图片已经放到了最大。");
clearInterval(largeTimer);
}
}else{
clearInterval(largeTimer);
}
},80);
}
var smallButton=document.getElementById("narrow");
smallButton.onclick=function(){
smaller();
}
var minWidth=image.width*0.5;
var minHeight=image.height*0.5;
function smaller(){
var endWidth=image.width*0.7;
var endHeight=image.height*0.7;
var smallTimer=setInterval(function(){
if(image.width>endWidth){
if(image.width>minWidth){
image.width=image.width*0.95;
image.height=image.height*0.95;
}else{
alert("此图片已经缩到了最小");
clearInterval(smallTimer);
}
}else{
clearInterval(smallTimer);
}
},130);
}
}
</script>
</body>
</html>
