页面加载GIF - 有人可以解释下面的答案吗？

Question

I found what I was looking for on this link How to show ajax loading gif animation while the page is loading? but I dont know how to implement this on my website.

I want a loading GIF to appear while the page loads and disappears by itself once the page is completely loaded with PHP results.

On the website I use one page template (index.php) and I have all data loaded in that page dynamically according to the user's query.

Thank you in advance.

Answer 1

Well, this is my solution.

1) CSS part

#loadgif {
    padding-top:2px;
    font: 10px #000;
    text-align:center;
    vertical-align:text-top;

    height: 80px;
    width: 130px;

    /* Centering the div to fit any screen resolution */
    top: 50%;
    left: 50%;
    margin-top: -41px; /* Div height divided by 2 including top padding */
    margin-left: -65px; /* Div width divided by 2 */
    position: absolute;
    display:    none; /* JS will change it to block display */
    position:   fixed;
    z-index:    1000;

    /* Loading GIF set as background of the div */
    background: #FFF url('../img/loader.gif') 50% 75% no-repeat;

    /* Misc decoration */
    -webkit-border-radius: 15px;
    -moz-border-radius: 15px;
    border-radius: 15px;
    border:#7580a8 solid 1px;
}

2) HTML part

Place div tag within body tag anywhere.

<!-- With or without text -->
<div id="loadgif">Loading...</div>

3) Javascript part

I made two functions, one to show and another to hide the div.

<script type="text/javascript">

// Hide function by changing <div> style display attribute back to none
function hideloadgif() {
    document.getElementById('loadgif').style.display = 'none';
}

// Show function by changing <div> style display attribute from none to block.
function showloadgif() {
    document.getElementById('loadgif').style.display = 'block';
}

// Making sure that any other event running in the background isn't affected
if (window.addEventListener) { // Mozilla, Netscape, Firefox
    window.addEventListener('load', WindowLoad, false);
} else if (window.attachEvent) { // IE
    window.attachEvent('onload', WindowLoad);
}

// Call the hideloadgif() function on click event,
// with interval time set to 3 seconds to hide the <div>
function WindowLoad(click) {
    setInterval("hideloadgif()",3000)
}
</script>

4) Showing the div. Call function showloadgif() using onlick="" event anywhere.

For example

<img src="abc/def.jpg" onlick="showloadgif()">

Once the image is clicked, the div will appear and at the same time, hideloadgif() will trigger and hides the div within 3 seconds.

function WindowLoad(click) {
    setInterval("hideloadgif()",3000)
}