JS 按比例自定义缩放图像

<center><font size='5' color='#fff'>按比例自定义缩放图像</font></center>

• img调用

  错误图像显示： onerror="onerror=null;src='/imgError.jpg'"

  <img onload="AutoResizeImage(100,100,this)" 
       onerror="onerror=null;src='/imgError.jpg'"
       class="rounded" src="/demo.jpg" alt="">
  

• js

  //按比例缩放图像
  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;
  }