Question

我有一个滚动页面功能但由于某种原因，向上滚动页面的第二个功能是针对前一个元素。你可以看出我的意思：

(function(root, $, undefined) {
"use strict";

// Change class of scrollbutton
$(window).scroll(function(){
($(this).scrollTop() > 300) ? ($('#scrollbutton').addClass('scrollup'),$('#scrollbutton').removeClass('scrolldown')) : ($('#scrollbutton').removeClass('scrollup'),$('#scrollbutton').addClass('scrolldown'));
});

// Scroll to block 2 element - Working
$("#scrollbutton.scrolldown").click(function() {
    $('html, body').animate({
        scrollTop: $(".block2").offset().top + -1
   }, 700);
});

// Scroll to block 1 element - Not Working it just scrolls to block 2!
$("#scrollbutton.scrollup").click(function() {
    $('html, body').animate({
        scrollTop: $(".block1").offset().top + -1
    }, 700);
});

}(this, jQuery));

...这里是HTML：

<body>
<main class="main">
<div class="block1">
blah
</div>
<div class="block2">
blah
</div>

</main>
<a id="scrollbutton" class="scrolldown">Top</a>

你可以直接用这个小提琴看到问题：

https://jsfiddle.net/ar0vq1ru/

感谢任何帮助或指导，谢谢。

Answer 1

这不起作用，因为从不调用秒onClick方法。你向听众说明$（＆＃34;＃scrollbutton.scrollup＆＃34;），它在开始时间不存在。如果向下滚动（然后交换类），它就会在那里

Answer 2

＆＃13;

(function(root, $, undefined) {
    "use strict";
    
    // Change class of scrollbutton
    $(window).scroll(function(){
    ($(this).scrollTop() > 300) ? ($('#scrollbutton').addClass('scrollup'),$('#scrollbutton').removeClass('scrolldown')) : ($('#scrollbutton').removeClass('scrollup'),$('#scrollbutton').addClass('scrolldown'));
    });
    
    // Scroll to block 2 element - Working
    $("#scrollbutton").click(function() {
  if($(this).hasClass("scrolldown")){
            $('html, body').animate({
            scrollTop: $(".block2").offset().top + -1
       }, 700);
       } else{
         $('html, body').animate({
            scrollTop: $(".block1").offset().top + -1
        }, 700)
       }      
       
       
    });
    
}(this, jQuery));

＆＃13;

.block1,.block2 {
  width: 90%;
  height:1000px;background:red;
}
.block2{background:green;}

#scrollbutton {
  display: inline-block;
  height: 40px;
  width: 40px;
  position: fixed;
  bottom: 40px;
  right: 10px;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.05);
  /* image replacement properties */
  overflow: hidden;
  text-indent: 100%;
  white-space: nowrap;
  background: rgba(0,0,0, 0.8) url('data:image/svg+xml;charset=US-ASCII,%3C%3Fxml%20version%3D%221.0%22%20encoding%3D%22utf-8%22%3F%3E%0D%0A%3C%21--%20Generator%3A%20Adobe%20Illustrator%2017.1.0%2C%20SVG%20Export%20Plug-In%20.%20SVG%20Version%3A%206.00%20Build%200%29%20%20--%3E%0D%0A%3C%21DOCTYPE%20svg%20PUBLIC%20%22-//W3C//DTD%20SVG%201.1//EN%22%20%22http%3A//www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd%22%3E%0D%0A%3Csvg%20version%3D%221.1%22%20id%3D%22Layer_1%22%20xmlns%3D%22http%3A//www.w3.org/2000/svg%22%20xmlns%3Axlink%3D%22http%3A//www.w3.org/1999/xlink%22%20x%3D%220px%22%20y%3D%220px%22%0D%0A%09%20width%3D%2216px%22%20height%3D%2216px%22%20viewBox%3D%220%200%2016%2016%22%20enable-background%3D%22new%200%200%2016%2016%22%20xml%3Aspace%3D%22preserve%22%3E%0D%0A%3Cpolygon%20fill%3D%22%23FFFFFF%22%20points%3D%228%2C2.8%2016%2C10.7%2013.6%2C13.1%208.1%2C7.6%202.5%2C13.2%200%2C10.7%20%22/%3E%0D%0A%3C/svg%3E%0D%0A') no-repeat center 50%;
  opacity: 1;
  -webkit-transition: opacity .3s 0s, visibility 0s .3s;
  -moz-transition: opacity .3s 0s, visibility 0s .3s;
  transition: opacity .3s 0s, visibility 0s .3s;transform:rotate(180deg);transition:all .5s ease-in-out;-webkit-transition:all .5s ease-in-out;-moz-transition:all .5s ease-in-out;
}

#scrollbutton.scrollup {
  visibility: visible;
  opacity: 1;transform:rotate(360deg);transition:all .5s ease-in-out;-webkit-transition:all .5s ease-in-out;-moz-transition:all .5s ease-in-out;
}

＆＃13;

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>

	<main class="main">
	<div class="block1">
	blah
	</div>
	<div class="block2">
	blah
	</div>
		
	</main>
	<a href="#0" id="scrollbutton" class="scrolldown">Top</a>

＆＃13;

Answer 3

问题是你的滚动点击不会发生（正如@Christian所说）。这是一个很好的解决方案：

替换

$("#scrollbutton.scrolldown").click(function() {

带

$('body').on('click',"#scrollbutton.scrolldown",function(){

并替换

$("#scrollbutton.scrollup").click(function() {

与

$('body').on('click',"#scrollbutton.scrollup",function(){

这会使用委派的事件（请参阅http://api.jquery.com/on/），并避免在您尝试附加活动时在网页上没有正确对象的问题。

jQuery瞄准错误的元素

3 个答案: