Rumah  >  Soal Jawab  >  teks badan

javascript - js做简单轮播图时出现错误,望大神指点。

<!DOCTYPE html>
<html>
<head>

<meta charset="utf-8">
<title>simple banner</title>
<style type="text/css">
#container{
    width: 300px;
    border: 1px solid green;
    margin: 100px auto;
    overflow: hidden;
}
#box{
    position: relative;
    width: 1200px;
    font-size: 0;
}
.child{
    width: 300px;
    height: 300px;
    line-height: 300px;
    text-align: center;
    display: inline-block;
    font-size: 20px;
    color: red;
}
</style>

</head>
<body>
<p id="container">

<p id="box">
    <p class="child">pic1</p>
    <p class="child">pic2</p>
    <p class="child">pic3</p>
    <p class="child">pic4</p>
</p>

</p>
<script type="text/javascript">

var box = document.getElementById('box');
var childs = box.getElementsByClassName('child');
var childwidth = parseInt(childs[0].offsetWidth);
var len = childs.length;
var index = 1;
var timers;

function myanimate(mgleft){
  if (parseInt(box.style.marginLeft) < -mgleft*index) {
    box.style.marginLeft = -(parseInt(box.style.marginLeft) + 10) + 'px';
    setTimeout(function(){
        myanimate(childwidth);
    }, 100));
  };
}
timers = setInterval(function(){
  if(index > len){
    index = 1;
  }
  myanimate(childwidth);
  index++;
},2000);

</script>
</body>
</html>

PHP中文网PHP中文网2723 hari yang lalu627

membalas semua(3)saya akan balas

  • 阿神

    阿神2017-04-10 16:53:02

    var childs=box.getElementsByClassName('child');
    应该写成var childs = box.children();

    balas
    0
  • 高洛峰

    高洛峰2017-04-10 16:53:02

    补充:dom.style.marginLeft只能取到行内样式如style="margin-left:20px"这样的值。

     if (parseInt(box.style.marginLeft) < -mgleft*index)//这里box.style.marginLeft为空,parseInt(box.style.marginLeft)的结果是NaN,if判断结果一直为假,所以函数相当于没执行

    如果是刚开始学轮播,去看一下慕课网上的这个课程吧 焦点轮播图特效
    一两个小时就能掌握,着重学习一下思想。基本思想学会了,自己再优化,或者去使用专门的插件,可以参考这个问题的部分答案 【求助】求一个轮播焦点图的jQuery代码
    -------


    控制台有指示,Uncaught SyntaxError: Unexpected token )
    你再点击截图右侧的文档就定位到具体哪一行了……

    setTimeout(function(){
        myanimate(childwidth);
    }, 100));//多了一个右括号

    balas
    0
  • 天蓬老师

    天蓬老师2017-04-10 16:53:02

    楼上把你的错误说得挺清楚了
    我这里就给你一个轮播图的案例好了,我随便在你的代码基础上写了一下,js代码不多,也很好理解,用了css3的属性,题主可以看看实现思路

    <!DOCTYPE html>
    <html>
    <head>
    <meta charset="utf-8">
    <title>simple banner</title>
    <style type="text/css">
    #container{
        width: 300px;
        border: 1px solid green;
        margin: 100px auto;
        /*overflow: hidden;*/
    }
    
    #cansee{
        position: relative;
        width: 300px;
        height: 300px;
        overflow: hidden;
        /*font-size: 0;*/
    }
    
    #box{
      position: absolute;
      width: 1200px;
      left: 0;
      -webkit-transition: left 0.8s ease-in-out;
      -o-transition: left 0.8s ease-in-out;
      transition: left 0.8s ease-in-out;
    }
    .child{
        width: 300px;
        height: 300px;
        line-height: 300px;
        text-align: center;
        font-size: 20px;
        color: white;
        float: left;
    }
    </style>
    </head>
    <body>
    <p id="container">
      <p id="cansee">
        <p id="box">
              <p class="child" style="background-color:blue">pic1</p>
              <p class="child" style="background-color:red">pic2</p>
              <p class="child" style="background-color:black">pic3</p>
              <p class="child" style="background-color:yellow">pic4</p>
        </p>
      </p>
    </p>
    <script type="text/javascript">
    var childs = box.getElementsByTagName("p");
    var childwidth = parseInt(childs[0].offsetWidth);
    var len = childs.length;
    var index = 1;
    var timers=setInterval(slide,2000);
    function slide(){
        box.style.left=childwidth*(-1)*index+'px';
        index++;
        if(index==len){
          index=0;
        }
    }
    </script>
    </body>
    </html>

    balas
    0
  • Batalbalas