js 控制图片大小核心讲解_javascript技巧

缩放图片脚本分享

重点js:

function AutoResizeImage(maxWidth,maxHeight){
var objImg = document.getElementById("operImg");
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}else if (maxHeight==0){
if (wRatio}else if (wRatioRatio = (wRatio}
if (Ratiow = w * Ratio;
h = h * Ratio;
}
objImg.height = h;
objImg.width = w;
}