js轮播效果实例分享

  
              
    

      
  
      
  
      
  
      
  
      
  
    
    
    
     

     
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/*图片轮播*/
var but1 = document.getElementById("prev");
var abtn = document.getElementById("btn").getElementsByTagName("li"); //获取所有的按钮
var lis = document.getElementById('allImg').getElementsByTagName('li');
var but2 = document.getElementById("next");
var index = 0;
var timer = null;
but2.Onclick= function() {

  index++;
  if (index > lis.length - 1) {
    index = 0;
  }
  setImg(index);

}
but1.Onclick= function() {
  index--;
  if (index <0) {
    index = lis.length - 1;
  }
  setImg(index);

}
function changeImg() {
  if (index == lis.length - 1) { //当到最后一张图片时
    index = 0
  } else {
    index++; //图片索引发生改变
  }
  setImg(index);
}
function setImg(index) {
  for (j = 0; j