Scrolling down to next element via keypress & scrollTo plugin - jQuery

问题

I am using jQuery's scrollTo plugin to scroll up and down my page, using UP arrow and DOWN arrow.

i have a bunch of div with class "screen", as so: <div class="screen-wrapper">...</div>

What I am trying to do is, when i press UP or DOWN, the window scrolls to the next, or previous div with class of "screen".

I have the keypresses taken care of. According to the plugin docs, to scroll a window, you use $.scrollTo(...);

Here's the code I have:

$(document).keypress(function(e){
    switch (e.keyCode) {
        case 40:    // down
            n = $('.screen-wrapper').next()
            $.scrollTo( n, 800 );
          break;
        case 38:    // up

          break;
        case 37:    // left

          break;
        case 39:    // right

          break;

    }      
});

And if it helps, here's the HTML div. I have a few of these on the page, and essentially, am trying to scroll to next one by pressing down arrow:

<div class='screen-wrapper'>
<div class='screen'>
    <div class="sections">
        <ul>
            <li><img src="images/portfolio/sushii-1.png " /></li>
            <li><img src="images/portfolio/sushii-2.png" /></li>
            <li><img src="images/portfolio/sushii-3.png" /></li>
        </ul>
    </div>

    <div class="next"></div>
    <div class="prev"></div>
</div>

And also if it needed, I can provide a link where this is being used if it'll help someone get a better idea.

edit And, i forgot to mention what the real question here is. The question/problem is that it won't scroll down past the first element, as seth mentioned.

回答1:

There's no real question here but I'm going to guess the problem is that your page doesn't scroll past the first one. It's because you call this on every keypress:

            n = $('.screen-wrapper').next()

It's probably returning the same one every single time you call it. Try moving the instantiation outside of the keypress.

          var s = $('.screen');
          var curr=-1, node;

          $(document).keypress(function(e){
             switch( e.keyCode ) {
               case 40:
                  node = s[++curr];
                  if (node) {
                    $.scrollTo( node,800);
                  }
                  else {
                    curr = s.length-1;
                  }
                  break;
                case 38:
                   node = s[--curr];
                   if (node) {
                     $.scrollTo( node ,800);
                   }
                   else {
                      curr = 0;
                    }
                   break;
                }
          });

回答2:

I just implemented something similar and I used id attributes for each element.

Why not do something like

window.location.href = '#section-' + curr;

instead of using scrollTo?

来源：https://stackoverflow.com/questions/1146748/scrolling-down-to-next-element-via-keypress-scrollto-plugin-jquery

标签

javascript

jquery

scrollto