javascript - 当我重新加载页面时，JQuery 的 Action 开始

Question

我想为我的菜单制作一个 slider 。它应该在实际事件的菜单项之上。 我无法在 codepen 中真正显示我的问题。但我可以显示我的 jquery:

https://codepen.io/Ayalann/pen/xrrjgg

我从 codepen 得到了这段代码

$("ul li").click(function(e) {

  // make sure we cannot click the slider
  if ($(this).hasClass('slider')) {
    return;
  }

  /* Add the slider movement */

  // what tab was pressed
  var whatTab = $(this).index();

  // Work out how far the slider needs to go
  var howFar = 160 * whatTab;

  $(".slider").css({
    left: howFar + "px"
  });

  /* Add the ripple */

  // Remove olds ones
  $(".ripple").remove();

  // Setup
  var posX = $(this).offset().left,
      posY = $(this).offset().top,
      buttonWidth = $(this).width(),
      buttonHeight = $(this).height();

  // Add the element
  $(this).prepend("<span class='ripple'></span>");

  // Make it round!
  if (buttonWidth >= buttonHeight) {
    buttonHeight = buttonWidth;
  } else {
    buttonWidth = buttonHeight;
  }

  // Get the center of the element
  var x = e.pageX - posX - buttonWidth / 2;
  var y = e.pageY - posY - buttonHeight / 2;

  // Add the ripples CSS and start the animation
  $(".ripple").css({
    width: buttonWidth,
    height: buttonHeight,
    top: y + 'px',
    left: x + 'px'
  }).addClass("rippleEffect");
});

@import url(https://fonts.googleapis.com/css?family=Lato:100,300,400,700);
* {
  box-sizing: border-box;
}

body {
  font-family: 'Lato', sans-serif;
  background: #222;
}

ul {
  font-size: 0;
  position: relative;
  padding: 0;
  width: 480px;
  margin: 40px auto;
  user-select: none;
}

li {
  display: inline-block;
  width: 160px;
  height: 60px;
  background: #39CCCC;
  font-size: 16px;
  text-align: center;
  line-height: 60px;
  color: #fff;
  text-transform: uppercase;
  position: relative;
  overflow: hidden;
  cursor: pointer;
}

.slider {
  display: block;
  position: absolute;
  bottom: 0;
  left: 0;
  height: 4px;
  background: yellow;
  transition: all 0.5s;
}
/*  Ripple */

.ripple {
  width: 0;
  height: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.4);
  transform: scale(0);
  position: absolute;
  opacity: 1;
}

.rippleEffect {
  animation: rippleDrop .6s linear;
}

@keyframes rippleDrop {
  100% {
    transform: scale(2);
    opacity: 0;
  }
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<ul>
  <li>Item One</li>
  <li>Item Two</li>
  <li>Item Three</li>
  <li class="slider"></li>
</ul>

我的问题是，当我单击页面中的菜单项时， slider 会移动，但当下载新页面时， slider 会转到开始位置。它不会停留在事件菜单项上方。

这就是我尝试这样做的原因:

  if ($(".sf-main-menu li").hasClass("active-trail")) {
  $(".slider").css({
    left: howFar + "px"
  });

但它不起作用。

我该如何解决这个问题？

Answer 1

创建一个函数并在其中传递事件 li 以定位 slider 并在您单击列表时调用相同的函数，例如，

$(function() {
  function menuChange(ths) {
    // make sure we cannot click the slider
    /* if ($(this).hasClass('slider')) {
       return;
     }*/
    /* Add the slider movement */

    // what tab was pressed
    var whatTab = $(ths).index();

    // Work out how far the slider needs to go
    var howFar = 100 * whatTab;

    /* $(".slider").css({
       left: howFar + "px"
     });*/

    if ($(".sf-main-menu li").hasClass("active-trail")) {
      $(".slider").css({
        left: howFar + "px"
      });

    }

  }
  $(".sf-main-menu li").click(function() {
    menuChange(this);
  });
  menuChange($(".sf-main-menu li.active-trail"));
  $('a').on('click',function(e){
    e.preventDefault();
  });
});

.slider {
  border-top: 3px solid green;
  height: 10px;
  width: 100px;
  opacity: .8;
  display: inline-block;
  left: 50px;
  transition: all 0.5s;
  position: absolute;
}

.sf-main-menu li {
  position: relative;
}

.sf-menu .active {
  color: green;
}

.sf-menu li {
  list-style-type: none;
  width: 100px;
  float: left;
  padding-top: 10px;
}

.sf-menu a {
  padding: 0 .5em;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<ul id="superfish-1" class="menu sf-menu sf-main-menu sf-horizontal sf-style-none sf-total-items-4 sf-parent-items-0 sf-single-items-4 superfish-processed sf-js-enabled">
  <li id="menu-2025-1" class="first odd sf-item-1 sf-depth-1 sf-no-children"><a href="/fooldal" title="" class="sf-depth-1">Főoldal</a></li>
  <li id="menu-396-1" class="active-trail middle even sf-item-2 sf-depth-1 sf-no-children"><a href="/hirek" class="sf-depth-1 active">Hírek</a></li>
  <li id="menu-399-1" class="middle odd sf-item-3 sf-depth-1 sf-no-children"><a href="/magunkrol" class="sf-depth-1">Magunkról</a></li>
  <li id="menu-400-1" class="last even sf-item-4 sf-depth-1 sf-no-children"><a href="/kapcsolat" class="sf-depth-1">Kapcsolat</a></li>
</ul>
<div class="slider"></div>