传入宽高 等比压缩图片
function proDownImage(width,height,size) {
var proMaxHeight=350;
var proMaxWidth = 400;
var ww = proMaxWidth / width;
var hh = proMaxHeight /height;
var rate = (ww < hh) ? ww: hh;
if (rate <= 1) {
size.width = width * rate;
size.height = height * rate;
} else {
size.width =width;
size.height =height;
}
return size;
}
function(e) {
var size = new Object();
size=proDownImage(Wflag,Hflag,size);
//可如此得到压缩后的宽高
size.height size.width.