我有一个图像滑块。以下是滑块的屏幕截图。
这工作正常..它会在单击下一个或上一个箭头时更改图像..但我想自动更改图像也意味着在某些时间间隔图像应该自动更改。我用谷歌搜索了很多，但我不知道该怎么做..请帮我解决这个问题...
提前致谢...
以下是代码：
<div id="slideshow">
<ul class="slides">
<li class="sl"><img class="ss" src="image/a.png" width="191" height="278" alt="Splash Screen" /></li>
<li class="sl"><img class="ss" src="image/b.png" width="191" height="278" alt="Select Route" /></li>
<li class="sl"><img class="ss" src="image/c.png" width="191" height="278" alt="New Schedule" /></li>
<li class="sl"><img class="ss" src="image/d.png" width="191" height="278" alt="Created Routes" /></li>
<li class="sl"><img class="ss" src="image/e.png" width="191" height="278" alt="CR" /></li>
</ul>
<span class="arrow next"></span>
<span class="arrow previous"></span>
</div>
以下是CSS：
#slideshow{
background:url(res/iphone_small.png) no-repeat;
height:512px;
/*margin:auto 30px;*/
margin:50px 25px auto;
position:relative;
width:257px;
}
#slideshow ul{
height:300px;
left:33px;
list-style:none outside none;
overflow:hidden;
position:absolute;
top:78px;
width:257px;
}
#slideshow li{
position:absolute;
display:none;
z-index:10;
}
#slideshow li:first-child{
display:block;
z-index:1000;
}
#slideshow .slideActive{
z-index:1000;
}
#slideshow canvas{
display:none;
position:absolute;
z-index:100;
}
#slideshow .arrow{
height:64px;
width:45px;
position:absolute;
background:url('res/arrows.png') no-repeat;
top:50%;
margin-top:-55px;
cursor:pointer;
z-index:5000;
margin-left:240px;
margin-right:240px;
}
#slideshow .previous{ background-position:right top;right:0;}
#slideshow .previous:hover{ background-position:right bottom;}
#slideshow .next{ background-position:left top;left:0;}
#slideshow .next:hover{ background-position:left bottom;}
以下是js文件：
$(window).load(function(){
// We are listening to the window.load event, so we can be sure
// that the images in the slideshow are loaded properly.
// Testing wether the current browser supports the canvas element:
var supportCanvas = 'getContext' in document.createElement('canvas');
// The canvas manipulations of the images are CPU intensive,
// this is why we are using setTimeout to make them asynchronous
// and improve the responsiveness of the page.
var slides = $('#slideshow li'),
current = 0,
slideshow = {width:0,height:0};
setTimeout(function(){
window.console && window.console.time && console.time('Generated In');
if(supportCanvas){
$('#slideshow img').each(function(){
if(!slideshow.width){
// Taking the dimensions of the first image:
slideshow.width = this.width;
slideshow.height = this.height;
}
// Rendering the modified versions of the images:
createCanvasOverlay(this);
});
}
window.console && window.console.timeEnd && console.timeEnd('Generated In');
$('#slideshow .arrow').click(function(){
var li = slides.eq(current),
canvas = li.find('canvas'),
nextIndex = 0;
// Depending on whether this is the next or previous
// arrow, calculate the index of the next slide accordingly.
if($(this).hasClass('next')){
nextIndex = current >= slides.length-1 ? 0 : current+1;
}
else {
nextIndex = current <= 0 ? slides.length-1 : current-1;
}
var next = slides.eq(nextIndex);
/*if(supportCanvas){
// This browser supports canvas, fade it into view:
canvas.fadeIn(function(){
// Show the next slide below the current one:
next.show();
current = nextIndex;
// Fade the current slide out of view:
li.fadeOut(function(){
li.removeClass('slideActive');
canvas.hide();
next.addClass('slideActive');
});
});
}
else {*/
// This browser does not support canvas.
// Use the plain version of the slideshow.
current=nextIndex;
next.addClass('slideActive').show();
li.removeClass('slideActive').hide();
//}
});
},100);
// This function takes an image and renders
// a version of it similar to the Overlay blending
// mode in Photoshop.
function createCanvasOverlay(image){
var canvas = document.createElement('canvas'),
canvasContext = canvas.getContext("2d");
// Make it the same size as the image
canvas.width = slideshow.width;
canvas.height = slideshow.height;
// Drawing the default version of the image on the canvas:
canvasContext.drawImage(image,0,0);
// Taking the image data and storing it in the imageData array:
var imageData = canvasContext.getImageData(0,0,canvas.width,canvas.height),
data = imageData.data;
// Loop through all the pixels in the imageData array, and modify
// the red, green, and blue color values.
for(var i = 0,z=data.length;i<z;i++){
// The values for red, green and blue are consecutive elements
// in the imageData array. We modify the three of them at once:
data[i] = ((data[i] < 128) ? (2*data[i]*data[i] / 255) : (255 - 2 * (255 - data[i]) * (255 - data[i]) / 255));
data[++i] = ((data[i] < 128) ? (2*data[i]*data[i] / 255) : (255 - 2 * (255 - data[i]) * (255 - data[i]) / 255));
data[++i] = ((data[i] < 128) ? (2*data[i]*data[i] / 255) : (255 - 2 * (255 - data[i]) * (255 - data[i]) / 255));
// After the RGB elements is the alpha value, but we leave it the same.
++i;
}
// Putting the modified imageData back to the canvas.
canvasContext.putImageData(imageData,0,0);
// Inserting the canvas in the DOM, before the image:
image.parentNode.insertBefore(canvas,image);
}
});