将背景图像居中对齐

Question

Here's the html:

<div class="gallerybox">
<a href="/CustomContentRetrieve.aspx?ID=398791">
<img alt="" src="/Utilities/image.jpg" width="400" height="400" />
</a>
</div>

Here's the css:

.gallerybox {width:200px;height:200px;overflow:hidden;}

Can anyone tell me a way to align the linked image inside div.gallerybox middle (vertically) and center (horizontaly)? Maybe using javascript, jQuery or just plain css?

Answer 1

Maybe something like the following:

<div class="gallerybox"> 
  <a href="/CustomContentRetrieve.aspx?ID=398791"> 
    <img id="imgUtility" class="galleryImage" alt="" src="/Utilities/ShowThumbnail.aspx?USM=1&amp;W=400&amp;H=400&amp;R=1&amp;Img={tag_image_value}" />"  /> 
  </a> 
</div> 

.gallerybox {
  width:200px;
  height:200px;
  overflow:hidden;
}

<!-- Edit Again -->
<script language="javascript">
window.onload = fixImage;

function fixImage() {
  var img = document.getElementById('imgUtility');
  var x = img.offsetWidth;
  var y = img.offsetHeight;

  img.style.left = -(x / 2);
  img.style.top = -(y / 2);
}
</script>

Answer 2

Jackson. I'm going to recommend a bit of an HTML rewrite, which I understand may not be possible, but I think this might be the most effective solution to your problem.

Create a hidden image with that database encoded <img> :

img#imgUtility {
   display: none;
}

(CSS and HTML)

<img id="imgUtility" class="galleryImage" alt=""
src="/Utilities/ShowThumbnail.aspx?USM=1&amp;W=350&amp;H=350&amp;
R=1&amp;Img={tag_image_value}" />

Then after the page has loaded and image has resolved to an actual URL, you can replace the <img> with a <span> in your posted HTML, set the hidden tag src to the background image of the <span> using it's inline style attribute via JavaScript:

// galleryBoxLinkTarget should be a reference to the <a> in a div.galleryBox
function imgReplacement(galleryBoxLinkTarget) {
   var span = document.createElement("span");
   var img = document.getElementById("imgUtility");
   span.style.backgroundImage = "url('" + img.getAttribute("src") + "')";
   span.className = "imgReplacement";
   galleryBoxLinkTarget.appendChild(span);
}

(JavaScript and HTML)

<div class="gallerybox">
   <a href="/CustomContentRetrieve.aspx?ID=398791">
      <!-- <span> goes here -->
   </a>
</div>

And then do a bit of clever CSS'ing:

span.imgReplacement {
   display: block;
   background-position: 50% 50%;
   background-repeat: no-repeat;
   width: 200px;
   height: 200px;
}

This should center the picture regardless of dimension, as well as allow you to remove the inline width and height attributes. Hope this works out for you!

Answer 3

Try this:

<style type="text/css">
  .gallerybox {text-align:center;vertical-align:middle;height:400px;line-height:400px;}
  .gallerbox img {display:inline; vertical-align:middle;}
</style>

<div class="gallerybox">
   <a href="/CustomContentRetrieve.aspx?ID=398791">
   <img alt="" src="/Utilities/image.jpg" />
</a>

Answer 4

Use a simple JQuery fn called center ( Usage: $(element).center() ):

     jQuery.fn.center = function() {
        this.css("position","absolute");
        this.css("top", (($(window).height() - this.outerHeight()) / 2) + $(window).scrollTop() + "px");
        this.css("left", (($(window).width() - this.outerWidth()) / 2) + $(window).scrollLeft() + "px");
        this.css("bottom", (($(window).width() - this.outerWidth()) / 2) + $(window).scrollLeft() + "px");
        return this;
      }
    $(document).ready(function(){
$(#imgUtility).center();
)};

With the HTML:

<div class="gallerybox"> 
  <a href="/CustomContentRetrieve.aspx?ID=398791"> 
    <img id="imgUtility" class="galleryImage" alt="" src="/Utilities/ShowThumbnail.aspx?USM=1&amp;W=400&amp;H=400&amp;R=1&amp;Img={tag_image_value}" />"  />  
  </a> 
</div>