JS实现按比例缩放图片的方法(附C#版代码)_javascript技巧

本文实例讲述了JS实现按比例缩放图片的方法。分享给大家供大家参考，具体如下：

js版本：

function resizeImage(obj, MaxW, MaxH)
{
 var imageObject = obj;
 var state = imageObject.readyState;
 if(state!='complete') 
 {
  setTimeout("resizeImage("+imageObject+","+MaxW+","+MaxH+")",50);
  return;
 }
 var oldImage = new Image();
 oldImage.src = imageObject.src;
 var dW = oldImage.width; 
 var dH = oldImage.height;
 if(dW>MaxW || dH>MaxH) 
 {
  a = dW/MaxW; b = dH/MaxH;
  if( b>a ) a = b;
  dW = dW/a; dH = dH/a;
 }
 if(dW > 0 && dH > 0) 
 {
  imageObject.width = dW;
  imageObject.height = dH;
 }
}

使用很简单：