js 判断图片加载完成

// HTML
<img id=‘xiu‘ src="http://www.daqianduan.com/wp-content/uploads/2014/11/hs-xiu.jpg">  

//js
 $(document).ready(function(){

    //jquery
    $(‘#xiu‘).load(function(){
       // 加载完成 
    });

   //原生  onload
    var xiu = document.getElementById(‘xiu‘)
    xiu.onload = xiu.onreadystatechange = function(){
       if(!this.readyState||this.readyState==‘loaded‘||this.readyState==‘complete‘){
           // 加载完成 
       }
    };

})

var img = [],  
    flag = 0, 
    mulitImg = [
    ‘http://www.daqianduan.com/wp-content/uploads/2017/03/IMG_0119.jpg‘,
    ‘http://www.daqianduan.com/wp-content/uploads/2017/01/1.jpg‘,
    ‘http://www.daqianduan.com/wp-content/uploads/2015/11/jquery.jpg‘,
    ‘http://www.daqianduan.com/wp-content/uploads/2015/10/maid.jpg‘
 ];
 var imgTotal = mulitImg.length;
 for(var i = 0 ; i < imgTotal ; i++){
    img[i] = new Image()
    img[i].src = mulitImg[i]
    img[i].onload = function(){
       //第i张图片加载完成
       flag++
       if( flag == imgTotal ){
          //全部加载完成
       }
    }
 }