How to switch pictures automatically or manually-JS Tutorial-php.cn

How to switch pictures automatically or manually

小云云

Release： 2018-01-30 09:21:21

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When I was learning JS, I accumulated a lot of interesting small examples, but I struggled to find some good platforms to show these JS effects, so I couldn’t wait to share them with you. In this article, we mainly introduce the jQuery automatic or manual image switching effect in detail. It has certain reference value. Interested friends can refer to it. I hope it can help you.

When browsing major shopping mall websites, or on the homepage of some websites, some real-time switching pictures related to this website will be displayed. This article will share with you an example of using jQuery to realize automatic switching of pictures.

Home page core code (Default.aspx):

<!DOCTYPE html> 
<html> 
<head> 
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 
    <title>jQuery实现图片切换</title>  
    <script type="text/javascript" src="js/jquery-1.4.2.min.js"></script> 
    <script type="text/javascript" src="js/tupianqiehuan.js"></script> 
    <link rel="stylesheet" type="text/css" href="css/tupianqiehuan.css"> 
</head> 
<body> 
    <p class="wrapper"> 
        <h1>jquer实现图片切换</h1> 
        <p id="focus"> 
            <ul> 
                <li><a href="#" target="_blank"><img src="images/01.jpg" alt="" /></a></li> 
                <li><a href="#" target="_blank"><img src="images/02.jpg" alt="" /></a></li> 
                <li><a href="#" target="_blank"><img src="images/03.jpg" alt="" /></a></li> 
                <li><a href="#" target="_blank"><img src="images/04.jpg" alt="" /></a></li><span style="white-space:pre">                 </ul> 
        </p> 
    </p> 
</body> 
</html>

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CSS code (tupianqiehuan.css):

*{margin:0;padding:0;} 
body{font-size:12px;color:#222;font-family:Verdana,Arial,Helvetica,sans-serif;background:#f0f0f0;} 
.clearfix:after{content: ".";display: block;height: 0;clear: both;visibility: hidden;} 
.clearfix{zoom:1;} 
ul,li{list-style:none;} 
img{border:0;} 
.wrapper{width:800px;margin:0 auto;padding-bottom:50px;} 
h1{height:50px;line-height:50px;font-size:22px;font-weight:normal;font-family:"Microsoft YaHei",SimHei;margin-bottom:20px;} 
/* focus */ 
#focus{width:800px;height:280px;overflow:hidden;position:relative;} 
#focus ul{height:380px;position:absolute;} 
#focus ul li{float:left;width:800px;height:280px;overflow:hidden;position:relative;background:#000;} 
#focus ul li p{position:absolute;overflow:hidden;} 
#focus .btnBg{position:absolute;width:800px;height:20px;left:0;bottom:0;background:#000;} 
#focus .btn{position:absolute;width:780px;height:10px;padding:5px 10px;right:0;bottom:0;text-align:right;} 
#focus .btn span{display:inline-block;_display:inline;_zoom:1;width:25px;height:10px;_font-size:0;margin-left:5px;cursor:pointer;background:#fff;} 
#focus .btn span.on{background:#fff;} 
#focus .preNext{width:45px;height:100px;position:absolute;top:90px;background:url(http://sandbox.runjs.cn/uploads/rs/475/xaqlrnnr/sprite.png) no-repeat 0 0;cursor:pointer;} 
#focus .pre{left:0;} 
#focus .next{right:0;background-position:right top;}

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JS code (tupianqiehuan.js):

$(function() { 
  var sWidth = $("#focus").width(); //获取焦点图的宽度（显示面积） 
  var len = $("#focus ul li").length; //获取焦点图个数 
  var index = 0; 
  var picTimer; 
   
  //以下代码添加数字按钮和按钮后的半透明条，还有上一页、下一页两个按钮 
  var btn = "<p class=&#39;btnBg&#39;></p><p class=&#39;btn&#39;>"; 
  for(var i=0; i < len; i++) { 
    btn += "<span></span>"; 
  } 
  btn += "</p><p class=&#39;preNext pre&#39;></p><p class=&#39;preNext next&#39;></p>"; 
  $("#focus").append(btn); 
  $("#focus .btnBg").css("opacity",0.5); 
 
  //为小按钮添加鼠标滑入事件，以显示相应的内容 
  $("#focus .btn span").css("opacity",0.4).mouseover(function() { 
    index = $("#focus .btn span").index(this); 
    showPics(index); 
  }).eq(0).trigger("mouseover"); 
 
  //上一页、下一页按钮透明度处理 
  $("#focus .preNext").css("opacity",0.2).hover(function() { 
    $(this).stop(true,false).animate({"opacity":"0.5"},300); 
  },function() { 
    $(this).stop(true,false).animate({"opacity":"0.2"},300); 
  }); 
 
  //上一页按钮 
  $("#focus .pre").click(function() { 
    index -= 1; 
    if(index == -1) {index = len - 1;} 
    showPics(index); 
  }); 
 
  //下一页按钮 
  $("#focus .next").click(function() { 
    index += 1; 
    if(index == len) {index = 0;} 
    showPics(index); 
  }); 
 
  //本例为左右滚动，即所有li元素都是在同一排向左浮动，所以这里需要计算出外围ul元素的宽度 
  $("#focus ul").css("width",sWidth * (len)); 
   
  //鼠标滑上焦点图时停止自动播放，滑出时开始自动播放 
  $("#focus").hover(function() { 
    clearInterval(picTimer); 
  },function() { 
    picTimer = setInterval(function() { 
      showPics(index); 
      index++; 
      if(index == len) {index = 0;} 
    },4000); //此4000代表自动播放的间隔，单位：毫秒 
  }).trigger("mouseleave"); 
   
  //显示图片函数，根据接收的index值显示相应的内容 
  function showPics(index) { //普通切换 
    var nowLeft = -index*sWidth; //根据index值计算ul元素的left值 
    $("#focus ul").stop(true,false).animate({"left":nowLeft},300); //通过animate()调整ul元素滚动到计算出的position 
    $("#focus .btn span").stop(true,false).animate({"opacity":"0.4"},300).eq(index).stop(true,false).animate({"opacity":"1"},300);//为当前的按钮切换到选中的效果  
  } 
});

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Related recommendations:

JavaScript tutorial--Click to cycle through pictures

Single picture pan switching implementation code

JavaScript implements mouse wheel control Page picture switching

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