Problem with degradable JavaScript slideshow
UPDATE: I've edited the code below to show what I was using when I tried to work with CSS visibility. I'm still stuck with this problem. I've also tried to remove the preloader() function from the body onLoad, but I can't use getElementById because the element hasn't loaded. My final thought was to just call rand(5) from within the HTML itself so that it adds a number to the end of the image filename if Javascript is enabled, but I'm not even sure how to incorporate that directly into the HTML. Any help would be greatly appreciated!
I created a slideshow with Javascript. The HTML calls a static image to display in the event Javascript is not enabled in the browser. If Javascript is enabled in the browser, it is supposed to load a random image in the place of the static image.
The problem I'm encountering is when Javascript is enabled, you see the static image load with the page and then, if the random image is different, you see it quickly load right after that. So it looks like two images cycling quickly on page load.
Here is the Javascript code I'm using:
// Define images used in slideshow
imgArray = new Array(
"header_img1.jpg",
"header_img2.jpg",
"header_img3.jpg",
"header_img4.jpg",
"header_img5.jpg"
);
baseURL = "images/";
// Preload slideshow images
function preloader() {
domElement = document.getElementById('gallery-image');
domElement.style.visibility = "hidden";
// counter
var i = 0;
// create object
imageObj = new Image();
// start preloading imgArray
for (i=0; i<3; i++) {
imageObj.src=imgAr开发者_运维百科ray[i];
}
}
// Select random image to display for slideshow
function random_img() {
domElement.style.visibility = "visible";
rand = Math.round(Math.random()*(imgArray.length - 1));
document["faces"].src = baseURL + imgArray[rand];
rand += 1;
}
Here is the accompanying HTML:
<body onLoad="preloader();random_img();">
.
.
.
<a href="#" onclick="f_slideshow(-1);return false;">
<img src="images/header_img1.png" alt="" width="26" height="207" /></a>
<img src="images/header_img1.jpg" alt="" width="529" height="197" class="img-1" name="faces" />
<a href="#" onclick="f_slideshow(1);return false;">
<img src="images/header_img2.png" alt="" width="27" height="207" /></a>
How do I change what I have so when Javascript is enabled, you don't see the two cycling images?
In your preLoader() manipulate the style to hide the elements you wish to hide if javascript is enabled.
This way, if it is enabled the elements will hide, if it is not, the clearly the javascript to hide them will not run.
example
var domElement = document.getElementById('id-of-element');
domElement.style.display = 'none';
This is the JavaScript code that solved my problem:
// Define images used in slideshow
imgArray = new Array(
"header_img1.jpg",
"header_img2.jpg",
"header_img3.jpg",
"header_img4.jpg",
"header_img5.jpg"
);
baseURL = "images/";
// Hide static image and preload slideshow images
function preloader() {
// counter
var i = 0;
// create object
imageObj = new Image();
// start preloading imgArray
for (i=0; i<3; i++) {
imageObj.src=imgArray[i];
}
}
// Control previous/next functions of slideshow
numImages = imgArray.length;
function f_slideshow( xflip ) {
// grab source of current image
var curImage = document["faces"].src;
// get image number from string and convert to int
curImage = parseInt(curImage.substring(curImage.length-5, curImage.length));
// create source for next/previous link
curImage = curImage + xflip;
if (curImage > numImages)
{ curImage = 1 ; }
if (curImage == 0)
{ curImage = numImages ; }
document["faces"].src = baseURL + imgArray[curImage - 1];
}
加载中,请稍侯......
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