Comment ajouter un fondu ou un effet de transition d'image en utilisant JQuery?

Question

J'ai juste un élément de <img> sur ma page. Je change l'attribut src de cette image toutes les 7 secondes.

Je vois les nouvelles images toutes les 7 secs, mais ce serait mieux si je peux ajouter un effet ou la décoloration des transitions lors du chargement de la nouvelle image.

Est-ce que certains ont simple script pour cela?

Je ne pas besoin de plug-in. Juste besoin des indices ou quelques lignes d'échantillon pour le faire.

Answer 1

Despite what KaiQing mentioned, you can use the callbacks ability of jQuery to fade in/out the image while you're changing it. This can be done like so: http://www.jsfiddle.net/bradchristie/HsKpq/1/

$('img').fadeOut('slow',function(){
    $(this).attr('src','/path/to/new_image.png').fadeIn('slow');
});

Answer 2

You'll want to use two images:

<img id="backImg" />
<img id="frontImg" />

Set #backImg to be behind #frontImg like so:

#backImg
{
    position: absolute;
}

Then, in your code that fires every 7 seconds, fadeOut the front image... this will automatically do your crossfade effect because the back image is already loaded behind it. When the fade is done, set the source of the front image to the back image's src, show it, and pre-load the next image into the back image:

function transitionImages(preloadImgUrl)
{
    $("#frontImg").fadeOut("slow", function()
    {
        $("#frontImg").attr("src", $("#backImg").attr("src")).show();
        $("#backImg").attr("src", preloadImgUrl);
    }
}

This all assumes your images are identically sized. If not, you'll want to be just a little more elaborate with the css and wrap the images in divs that fade out.

Answer 3

You can't do this with just one image.

Check this out:

    <div id="main_over"></div> 
    <div id="main_img"></div> 
    <div id="himg" style="display:none; clear:both; margin-top:40px;"> 

            <img id="si_15" src="http://website.com/media/uploaded/home_slideshow/53/dummy_image_large_1__large.jpg" alt="dummy_image_large_1" /> 

            <img id="si_16" src="http://website.com/media/uploaded/home_slideshow/53/dummy_image_large_2__large.jpg" alt="dummy_image_large_2" /> 

            <img id="si_17" src="http://website.com/media/uploaded/home_slideshow/53/dummy_image_large_3__large.jpg" alt="dummy_image_large_3" /> 

            <img id="si_18" src="http://website.com/media/uploaded/home_slideshow/53/dummy_image_large_4__large.jpg" alt="dummy_image_large_4" /> 

    </div> 
<style> 
#main_over{position:absolute; z-index:10; width:800px; height:600px; background:#fff; display:block;}
</style> 
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script> 
<script type="text/javascript"> 
$(document).ready(function(){
    var i = 0;
    $('#himg img').each(function(){
        if(i == 0)
        {
            $('#main_over').html('<img src="' + $(this).attr('src') + '" alt="" />');

        }
        if(i == 1)
        {
            $('#main_img').html('<img src="' + $(this).attr('src') + '" alt="" />');
        }
        i ++;

        slide.arr.push($(this).attr('src')); 
    });

    setTimeout(function(){
        if(slide.arr.length < 2)
            slide.fade(0);
        else
            slide.fade(2);
    }, 3000);
});

var slide = {
    arr: Array(),
    fade: function(i)
    {
        $('#main_over').fadeOut("medium");
        setTimeout(function(){slide.next(i);}, 1000);
    },
    next: function(i)
    {
        $('#main_over').html($('#main_img').html());
        $('#main_over').css('display', 'block');

        $('#main_img').html('<img src="' + slide.arr[i] + '" alt="" />');

        i++;
        if(i >= slide.arr.length)
            i = 0;

        setTimeout(function(){slide.fade(i);}, 3000);
    }
}

</script>