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Complete example of JS picture scaling method

  • 2021-07-09 06:39:22
  • OfStack

In this paper, an example is given to describe the method of equal scaling of JS pictures. Share it for your reference, as follows: 


<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>javascript Auto-scaled picture display, scaled compressed picture display </title>
<script type="text/javascript">
function AutoResizeImage(maxWidth,maxHeight,objImg){
var img = new Image();
img.src = objImg.src;
var hRatio;
var wRatio;
var Ratio = 1;
var w = img.width;
var h = img.height;
wRatio = maxWidth / w;
hRatio = maxHeight / h;
if (maxWidth ==0 && maxHeight==0){
Ratio = 1;
}else if (maxWidth==0){//
if (hRatio<1) Ratio = hRatio;
}else if (maxHeight==0){
if (wRatio<1) Ratio = wRatio;
}else if (wRatio<1 || hRatio<1){
Ratio = (wRatio<=hRatio?wRatio:hRatio);
}
if (Ratio<1){
w = w * Ratio;
h = h * Ratio;
}
objImg.height = h;
objImg.width = w;
}
</script>
</head>
<body>
<br />
<img src="1.jpg"
   border="0"
 width="0"
 height="0"
 onload="AutoResizeImage(100,0,this)"
 />
width:100px
<br />
<br />
<img src="1.jpg"
   border="0"
 width="0"
 height="0"
 onload="AutoResizeImage(0,100,this)"
 />
height:100px
<br />
<br />
<img src="1.jpg"
   border="0"
 width="0"
 height="0"
 onload="AutoResizeImage(100,100,this)"
 />
width:100px height:100px
<br />
<br />
<br />
<br />
<br />
<br />
<br />
</body>
</html>

More readers interested in JavaScript can check the topics of this site: "Summary of JavaScript Switching Effects and Skills", "Summary of JavaScript Search Algorithm Skills", "Summary of JavaScript Animation Effects and Skills", "Summary of JavaScript Error and Debugging Skills", "Summary of JavaScript Data Structure and Algorithm Skills", "Summary of JavaScript Traversal Algorithms and Skills" and "Summary of JavaScript Mathematical Operation Usage"

I hope this article is helpful to everyone's JavaScript programming.

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