Change image in HTML page every few seconds

2020-01-26 05:18发布

问题:

I want to change images every few seconds, this is my code:

<?xml version = "1.0" encoding = "utf-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
   "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<html xmlns = "http://www.w3.org/1999/xhtml">
   <head>
      <title>change picture</title>
      <script type = "text/javascript">

    function changeImage()
    {
    var img = document.getElementById("img");
    img.src = images[x];
    x++;

    if(x >= images.length){
        x = 0;
    } 
   var timerid = setInterval(changeImage(), 1000);
}   }
var images = [], x = 0;
images[0] = "image1.jpg";
images[1] = "image2.jpg";
images[2] = "image3.jpg";

      </script>
   </head>
   <body onload = "changeImage()">
 <img id="img" src="startpicture.jpg">
   </body>
</html>

My problem is its stuck on the first picture!

I also wanted to try flipping through the pictures with previous and next buttons but I have no idea how to do that.

回答1:

As I posted in the comment you don't need to use both setTimeout() and setInterval(), moreover you have a syntax error too (the one extra }). Correct your code like this:

(edited to add two functions to force the next/previous image to be shown)

<!DOCTYPE html>

<html>
   <head>
      <title>change picture</title>
      <script type = "text/javascript">
          function displayNextImage() {
              x = (x === images.length - 1) ? 0 : x + 1;
              document.getElementById("img").src = images[x];
          }

          function displayPreviousImage() {
              x = (x <= 0) ? images.length - 1 : x - 1;
              document.getElementById("img").src = images[x];
          }

          function startTimer() {
              setInterval(displayNextImage, 3000);
          }

          var images = [], x = -1;
          images[0] = "image1.jpg";
          images[1] = "image2.jpg";
          images[2] = "image3.jpg";
      </script>
   </head>

   <body onload = "startTimer()">
       <img id="img" src="startpicture.jpg"/>
       <button type="button" onclick="displayPreviousImage()">Previous</button>
       <button type="button" onclick="displayNextImage()">Next</button>
   </body>
</html>


回答2:

below will change link and banner every 10 seconds

   <script>
        var links = ["http://www.abc.com","http://www.def.com","http://www.ghi.com"];
        var images = ["http://www.abc.com/1.gif","http://www.def.com/2.gif","http://www.ghi.com/3gif"];
        var i = 0;
        var renew = setInterval(function(){
            if(links.length == i){
                i = 0;
            }
            else {
            document.getElementById("bannerImage").src = images[i]; 
            document.getElementById("bannerLink").href = links[i]; 
            i++;

        }
        },10000);
        </script>



<a id="bannerLink" href="http://www.abc.com" onclick="void window.open(this.href); return false;">
<img id="bannerImage" src="http://www.abc.com/1.gif" width="694" height="83" alt="some text">
</a>


回答3:

Change setTimeout("changeImage()", 30000); to setInterval("changeImage()", 30000); and remove var timerid = setInterval(changeImage, 30000);.



回答4:

As of current edited version of the post, you call setInterval at each change's end, adding a new "changer" with each new iterration. That means after first run, there's one of them ticking in memory, after 100 runs, 100 different changers change image 100 times every second, completely destroying performance and producing confusing results.

You only need to "prime" setInterval once. Remove it from function and place it inside onload instead of direct function call.



回答5:

You can load the images at the beginning and change the css attributes to show every image.

var images = array();
for( url in your_urls_array ){
   var img = document.createElement( "img" );
   //here the image attributes ( width, height, position, etc )
   images.push( img );
}

function player( position )
{
  images[position-1].style.display = "none" //be careful working with the first position
  images[position].style.display = "block";
  //reset position if needed
  timer = setTimeOut( "player( position )", time );
}


回答6:

Best way to swap images with javascript with left vertical clickable thumbnails

SCRIPT FILE: function swapImages() {

    window.onload = function () {
        var img = document.getElementById("img_wrap");
        var imgall = img.getElementsByTagName("img");
        var firstimg = imgall[0]; //first image
        for (var a = 0; a <= imgall.length; a++) {
            setInterval(function () {
                var rand = Math.floor(Math.random() * imgall.length);
                firstimg.src = imgall[rand].src;
            }, 3000);



            imgall[1].onmouseover = function () {
                 //alert("what");
                clearInterval();
                firstimg.src = imgall[1].src;


            }
            imgall[2].onmouseover = function () {
                clearInterval();
                firstimg.src = imgall[2].src;
            }
            imgall[3].onmouseover = function () {
                clearInterval();
                firstimg.src = imgall[3].src;
            }
            imgall[4].onmouseover = function () {
                clearInterval();
                firstimg.src = imgall[4].src;
            }
            imgall[5].onmouseover = function () {
                clearInterval();
                firstimg.src = imgall[5].src;
            }
        }

    }


}