Unslider：甚至在“低”屏幕分辨率下居中图像

Question

我在项目中使用了Unslider（http://unslider.com/）。

我成功地将整个滑块部分对准目标的一半。 但问题是，1920和更低的宽度分辨率的幻灯片不集中。图像的宽度是3940像素。

我试图应用this答案的代码;像这样：

$(function() { 
    $('.banner').unslider(); 
    AdjustSliderImgWrapper(); 
}); 

$(window).resize(AdjustSliderImgWrapper); 

function AdjustSliderImgWrapper() { 
    var left = (parseInt($('.banner > li > img').width()) - $('.banner > li').innerWidth())/-2; 
    $('.banner > li > img').css('left', left); 
} 

，但无济于事。我也试过：

$(".banner img").each(function() { 
    $(this).css("margin-left", -this.width/2); 
}) 

也：

background-position: center center !important; 

这里是我的代码：

window.console && console.warn("This version of Unslider is due to be deprecated by December 1. Please visit unslider.com for details on how to upgrade."), function (t, s) { 
 
\t if (!t) 
 
\t \t return s; 
 
\t var i = function() { 
 
\t \t this.el = s, 
 
\t \t this.items = s, 
 
\t \t this.sizes = [], 
 
\t \t this.max = [0, 0], 
 
\t \t this.current = 0, 
 
\t \t this.interval = s, 
 
\t \t this.opts = { 
 
\t \t \t speed : 500, 
 
\t \t \t delay : 3e3, 
 
\t \t \t complete : s, 
 
\t \t \t keys : !s, 
 
\t \t \t dots : s, 
 
\t \t \t fluid : s 
 
\t \t }; 
 
\t \t var i = this; 
 
\t \t this.init = function (s, i) { 
 
\t \t \t return this.el = s, 
 
\t \t \t this.ul = s.children("ul"), 
 
\t \t \t this.max = [s.outerWidth(), s.outerHeight()], 
 
\t \t \t this.items = this.ul.children("li").each(this.calculate), 
 
\t \t \t this.opts = t.extend(this.opts, i), 
 
\t \t \t this.setup(), 
 
\t \t \t this 
 
\t \t }, 
 
\t \t this.calculate = function (s) { 
 
\t \t \t var e = t(this), 
 
\t \t \t n = e.outerWidth(), 
 
\t \t \t h = e.outerHeight(); 
 
\t \t \t i.sizes[s] = [n, h], 
 
\t \t \t n > i.max[0] && (i.max[0] = n), 
 
\t \t \t h > i.max[1] && (i.max[1] = h) 
 
\t \t }, 
 
\t \t this.setup = function() { 
 
\t \t \t if (this.el.css({ 
 
\t \t \t \t \t overflow : "hidden", 
 
\t \t \t \t \t width : i.max[0], 
 
\t \t \t \t \t height : this.items.first().outerHeight() 
 
\t \t \t \t }), this.ul.css({ 
 
\t \t \t \t \t width : 100 * this.items.length + "%", 
 
\t \t \t \t \t position : "relative" 
 
\t \t \t \t }), this.items.css("width", 100/this.items.length + "%"), this.opts.delay !== s && (this.start(), this.el.hover(this.stop, this.start)), this.opts.keys && t(document).keydown(this.keys), this.opts.dots && this.dots(), this.opts.fluid) { 
 
\t \t \t \t var e = function() { 
 
\t \t \t \t \t i.el.css("width", Math.min(Math.round(i.el.outerWidth()/i.el.parent().outerWidth() * 100), 100) + "%") 
 
\t \t \t \t }; 
 
\t \t \t \t e(), 
 
\t \t \t \t t(window).resize(e) 
 
\t \t \t } 
 
\t \t \t this.opts.arrows && this.el.parent().append('<p class="arrows"><span class="prev">â†</span><span class="next">→</span></p>').find(".arrows span").click(function() { 
 
\t \t \t \t t.isFunction(i[this.className]) && i[this.className]() 
 
\t \t \t }), 
 
\t \t \t t.event.swipe && this.el.on("swipeleft", i.prev).on("swiperight", i.next) 
 
\t \t }, 
 
\t \t this.move = function (s, e) { 
 
\t \t \t this.items.eq(s).length || (s = 0), 
 
\t \t \t 0 > s && (s = this.items.length - 1); 
 
\t \t \t var n = this.items.eq(s), 
 
\t \t \t h = { 
 
\t \t \t \t height : n.outerHeight() 
 
\t \t \t }, 
 
\t \t \t o = e ? 5 : this.opts.speed; 
 
\t \t \t this.ul.is(":animated") || (i.el.find(".dot:eq(" + s + ")").addClass("active").siblings().removeClass("active"), this.el.animate(h, o) && this.ul.animate(t.extend({ 
 
\t \t \t \t \t \t left : "-" + s + "00%" 
 
\t \t \t \t \t }, h), o, function() { 
 
\t \t \t \t \t i.current = s, 
 
\t \t \t \t \t t.isFunction(i.opts.complete) && !e && i.opts.complete(i.el) 
 
\t \t \t \t })) 
 
\t \t }, 
 
\t \t this.start = function() { 
 
\t \t \t i.interval = setInterval(function() { 
 
\t \t \t \t \t i.move(i.current + 1) 
 
\t \t \t \t }, i.opts.delay) 
 
\t \t }, 
 
\t \t this.stop = function() { 
 
\t \t \t return i.interval = clearInterval(i.interval), 
 
\t \t \t i 
 
\t \t }, 
 
\t \t this.keys = function (s) { 
 
\t \t \t var e = s.which, 
 
\t \t \t n = { 
 
\t \t \t \t 37 : i.prev, 
 
\t \t \t \t 39 : i.next, 
 
\t \t \t \t 27 : i.stop 
 
\t \t \t }; 
 
\t \t \t t.isFunction(n[e]) && n[e]() 
 
\t \t }, 
 
\t \t this.next = function() { 
 
\t \t \t return i.stop().move(i.current + 1) 
 
\t \t }, 
 
\t \t this.prev = function() { 
 
\t \t \t return i.stop().move(i.current - 1) 
 
\t \t }, 
 
\t \t this.dots = function() { 
 
\t \t \t var s = '<ol class="dots">'; 
 
\t \t \t t.each(this.items, function (t) { 
 
\t \t \t \t s += '<li class="dot' + (1 > t ? " active" : "") + '">' + (t + 1) + "</li>" 
 
\t \t \t }), 
 
\t \t \t s += "</ol>", 
 
\t \t \t this.el.addClass("has-dots").append(s).find(".dot").click(function() { 
 
\t \t \t \t i.move(t(this).index()) 
 
\t \t \t }) 
 
\t \t } 
 
\t }; 
 
\t t.fn.unslider = function (s) { 
 
\t \t var e = this.length; 
 
\t \t return this.each(function (n) { 
 
\t \t \t var h = t(this), 
 
\t \t \t o = (new i).init(h, s); 
 
\t \t \t h.data("unslider" + (e > 1 ? "-" + (n + 1) : ""), o) 
 
\t \t }) 
 
\t } 
 
} 
 
(window.jQuery, !1);

* { 
 
    margin: 0; 
 
    padding: 0; 
 
} 
 
#outermin1 { 
 
width : 100%; 
 
} 
 
.banner { 
 
position : relative; 
 
width : auto !important; 
 
overflow : auto; 
 
text-align : center; 
 
} 
 
/* 
 
*/ 
 

 
.banner ul { 
 
list-style : none; 
 
width : 300%; 
 
padding: 0px; 
 
} 
 
.banner ul li { 
 
display : block; 
 
float : left; 
 
width : 33%; 
 
padding : 0 0 110px; 
 
min-height: 1550px !important; 
 
max-height: 1550px !important; 
 
} 
 
.banner h1 { 
 
position : relative; 
 
margin : 0 auto; 
 
height : 120px; 
 
top : 30px; 
 
text-align : center; 
 
font-size : 250% !important ; 
 
color : #FFF; 
 
text-transform : uppercase; 
 
font-weight : 100; 
 
/*line-height : 38px !important ;*/ 
 
} 
 
.banner h2 { 
 
text-transform : none; 
 
font-size : 150%; 
 
top : -15px; 
 
position : relative; 
 
color : #FFF; 
 
} 
 
.banner .btn { 
 
display : inline-block; 
 
margin : 25px 0 0; 
 
padding : 9px 22px 7px; 
 
clear : both; 
 
color : #fff; 
 
font-size : 12px; 
 
font-weight : 700; 
 
text-transform : uppercase; 
 
text-decoration : none; 
 
border : rgba(255, 255, 255, 0.4) solid 2px; 
 
border-radius : 5px; 
 
} 
 
.banner .btn:hover { 
 
background : rgba(255, 255, 255, 0.05); 
 
} 
 
.banner .dots { 
 
    position: absolute; 
 
    left: 0px; 
 
    right: 0px; 
 
    bottom: -10px; 
 
    background: #fff; 
 
    height: 103px; 
 
    padding-top: 30px; 
 
} 
 
.banner .dots li { 
 
display : inline-block; 
 
width : 10px; 
 
height : 10px; 
 
margin : 0 4px; 
 
text-indent : -999em; 
 
border : #17b7a5 solid 2px; 
 
border-radius : 6px; 
 
cursor : pointer; 
 
opacity : 0.4000000059604644775390625; 
 
transition : background 0.5s, opacity 0.5s; 
 
} 
 
.banner .dots li.active { 
 
background : #17b7a5; 
 
opacity : 1; 
 
} 
 
/* 
 
.banner img { 
 
    width: 100%; 
 
    margin-top: -143px; 
 
}*/ 
 
.banner img { 
 
    background-size: cover; 
 
    z-index: 3; 
 
} 
 
/* this is the tryout part */ 
 
.banner > li { position: relative; } 
 
.banner > li > img { position: absolute; top: 0; width: 3940px !important; text-align: center;}

<!DOCTYPE html> 
 
<html lang="en"> 
 
    <head> 
 
    <meta charset="utf-8"> 
 
    <meta http-equiv="X-UA-Compatible" content="IE=edge"> 
 
    <meta name="viewport" content="width=device-width, initial-scale=1"> 
 
    <!-- The above 3 meta tags *must* come first in the head; any other head content must come *after* these tags --> 
 
    <meta name="description" content=""> 
 
    <meta name="author" content=""> 
 
    <link rel="icon" href="favicon.ico"> 
 

 
    <title>theimapcter.org</title> 
 

 
    <!-- Bootstrap core CSS --> 
 
    <link href="css/bootstrap.min.css" rel="stylesheet"> 
 
    <!-- IE10 viewport hack for Surface/desktop Windows 8 bug --> 
 
    <link href="css/ie10-viewport-bug-workaround.css" rel="stylesheet"> 
 

 
    <!-- Custom styles for this template --> 
 
    <link href="css/banner.css" rel="stylesheet"> 
 
    <link href="css/egyedi.css" rel="stylesheet"> <!-- a kialakitas --> 
 
\t 
 

 
    <!-- HTML5 shim and Respond.js for IE8 support of HTML5 elements and media queries --> 
 
    <!--[if lt IE 9]> 
 
     <script src="https://oss.maxcdn.com/html5shiv/3.7.2/html5shiv.min.js"></script> 
 
     <script src="https://oss.maxcdn.com/respond/1.4.2/respond.min.js"></script> 
 
    <![endif]--> 
 
<script src="http://code.jquery.com/jquery-latest.min.js"></script> 
 
<script src="js/unslider.min.js"></script> 
 
\t  <script type="text/javascript"> 
 
$(function() { 
 
    $('.banner').unslider({ 
 
    speed: 500,    
 
    delay: 15000,    
 
    complete: function() {}, 
 
    keys: true,    
 
    dots: true,    
 
    fluid: true    
 
    }); 
 
}); 
 

 
</script> 
 
    </head> 
 

 
    <body> 
 

 
    <nav class="navbar navbar-inverse navbar-fixed-top"> 
 
     <div class="navbar-header"> 
 
      <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#navbar" aria-expanded="false" aria-controls="navbar"> 
 
      <span class="sr-only">Toggle navigation</span> 
 
      <span class="icon-bar"></span> 
 
      <span class="icon-bar"></span> 
 
      <span class="icon-bar"></span> 
 
      </button> 
 
    \t \t <a class="navbar-brand" href="#"><img src="svg/impacter_logo_fejlec.svg" alt="logo"></a>   
 
     </div> 
 
    <div id="navbar" class="collapse navbar-collapse" > 
 
     <ul class="nav navbar-nav"> 
 
      <li><a href="">Projects</a></li> 
 
      <li><a href="">Mindset</a></li> 
 
      <li><a href="">Make an impact</a></li> 
 
      <li><a href="">Search</a></li> 
 
      <li><a href="">Login/Register</a></li> 
 
     </ul> 
 
    </div> 
 
    </nav> 
 
    <div class="box" id="outermin1" style="z-index:4"> 
 
    <!--banner--> 
 
<div class="banner"> 
 
    <ul> 
 
     <li style="background:#00b8a5;"><div class="slider-wrapper"><div class="slide-outer"><div class="slide-szoveg"> 
 
\t \t <h1 class="cim1">Do you have the ability to respond challenges?</h1><h2 class="cim2">In other words: how do you deal with responsibility?</h2><br/><div class="start-slide"><span class="start-slide1">Start</span><br/><span class="start-slide2">the responsibility quick TEST!</span></div><span class="join-slide">Join the social experiment</span> 
 
\t \t <span class="use-slide">Use Impacter platform to develop new ways and solve actual social/environmental<br/>challenges responsibly – meanwhile learn about yourself.</span><span class="find-slide">Find your challenge</span></div></div><img src="https://dl.dropboxusercontent.com/s/8nop7364npk31ue/slide1.png" alt="lab" class="slide1" /></div> 
 
\t \t </li> 
 
     <li style="background:#8fc453;"><div class="slider-wrapper"><div class="slide-outer"><div class="slide-szoveg"> 
 
\t \t <h1 class="cim3">Projects with real-life impact</h1><h2 class="cim3">Activate ideas to generate change </h2><br/><br/><span>Upload a challenge</span>&nbsp;<span>Join a project</span></div></div><img src="https://dl.dropboxusercontent.com/s/7l99ejj81bd2g1d/slide2.png" alt="World map" class="slide2" /></div> 
 
\t \t </li> 
 
\t \t <li style="background:#37c6ea;"><div class="slider-wrapper"><div class="slide-outer"><div class="slide-szoveg"> 
 
\t \t <h1>Develop new ways to solve actual social/environmental challenges</h1><br/><br/><h2><strong class="line2">– meanwhile learn about yourself.</strong></h2><span>Challenges</span><span>Taking<br/>the responsibility</span><span>Response</span><span>Make an impact</span></div></div><img src="https://dl.dropboxusercontent.com/s/geiezcd6hym6mxt/slide3.png" alt="people on pc" class="slide3" /></div></li> 
 
    </ul> 
 
\t <div style="height:50px;">&nbsp;</div> 
 
</div> 
 

 
</div> 
 
    <!-- Main jumbotron for a primary marketing message or call to action --> 
 

 
<!--<div id="banner-alatt">--> 
 
    <div class="container"> 
 
     <!-- Example row of columns --> 
 
     <div class="row"> 
 
     <div class="col-md-4"> 
 
      <h2>Heading</h2> 
 
      <p>Donec id elit non mi porta gravida at eget metus. Fusce dapibus, tellus ac cursus commodo, tortor mauris condimentum nibh, ut fermentum massa justo sit amet risus. Etiam porta sem malesuada magna mollis euismod. Donec sed odio dui. </p> 
 
      <p><a class="btn btn-default" href="#" role="button">View details &raquo;</a></p> 
 
     </div> 
 
     <div class="col-md-4"> 
 
      <h2>Heading</h2> 
 
      <p>Donec id elit non mi porta gravida at eget metus. Fusce dapibus, tellus ac cursus commodo, tortor mauris condimentum nibh, ut fermentum massa justo sit amet risus. Etiam porta sem malesuada magna mollis euismod. Donec sed odio dui. </p> 
 
      <p><a class="btn btn-default" href="#" role="button">View details &raquo;</a></p> 
 
     </div> 
 
     <div class="col-md-4"> 
 
      <h2>Heading</h2> 
 
      <p>Donec sed odio dui. Cras justo odio, dapibus ac facilisis in, egestas eget quam. Vestibulum id ligula porta felis euismod semper. Fusce dapibus, tellus ac cursus commodo, tortor mauris condimentum nibh, ut fermentum massa justo sit amet risus.</p> 
 
      <p><a class="btn btn-default" href="#" role="button">View details &raquo;</a></p> 
 
     </div> 
 
     </div> 
 

 
     <hr> 
 

 
     <footer> 
 
     <p>&copy; 2015 Company, Inc.</p> 
 
     </footer> 
 
    </div> <!-- /container --> 
 
<!-- </div> --> 
 

 
    <!-- <script>window.jQuery || document.write('<script src="../../assets/js/vendor/jquery.min.js"><\/script>')</script> --> 
 
    <script src="js/bootstrap.min.js"></script> 
 
    <!-- IE10 viewport hack for Surface/desktop Windows 8 bug --> 
 
    <script src="js/ie10-viewport-bug-workaround.js"></script> 
 
    </body> 
 
</html>

编辑2016年7月23日： 我忘了提到那个我只想将图像的1920px部分居中。

Answer 1

解决的办法是：包装图像在父类和广告孩子类图像，

<span class="parent"><img class="child"...> 

，并给他们的中心，就像这样：

.parent { 
    position: relative; 
    overflow: hidden; 
} 

.child { 
    position: absolute; 
    left: -9999px; 
    right: -9999px; 
    margin: auto; 
} 

然后加入overflow:hidden;到.banner ul li以使div不会相互重叠。

Answer 2

我更喜欢另一个技巧。我不知道您的特定滑块是否可以为div生成动画，但是您可以将该图像作为背景图像提供给该div。比使用background-size: cover;和浏览器将始终为您选择合适的大小。