Question

我正在构建一个下拉菜单，需要向其添加以下功能：

当一个下拉列表打开并且您打开另一个下拉列表时，前一个下拉列表需要在新下拉列表开始打开之前完全关闭，无论下拉速度设置为多快或多慢。

JQuery的

$(document).ready(function() {

$(".click").on("click", function(evt) {
   evt.stopPropagation();
  var th = $(this);

  if (th.hasClass("active")) {
    th.removeClass("active");
   th.parent().find(".showup").slideUp(900);
   $(".main-container").removeClass("black-bg");
  }else{
    $(".active").removeClass("active");
    $(".showup").slideUp(900);
    $(".main-container").removeClass("black-bg");
    setTimeout(function(){
    th.addClass("active");
    th.parent().find(".showup").slideDown(900);
$(".main-container").addClass("black-bg");
    },250);

  }

});
$(".showup").on("click", function(evt) {
    evt.stopPropagation();
});

});

$(document).on("click", function() {
    $(".active").parent().find(".showup").slideUp(900);
    $(".active").toggleClass("active");
    if ($(".main-container").hasClass("black-bg")) {
      $(".main-container").toggleClass("black-bg");
    }
});

感谢您的帮助。

Answer 1

检查是否有.active，如果是，setTimeout()有900毫秒，如果没有，setTimeout()有0毫秒（实际上它是4 miliseconds但它会永远不会100％准确）。

$(document).ready(function() {

  $(".click").on("click", function(evt) {
    evt.stopPropagation();
    var th = $(this);

    if (th.hasClass("active")) {
      th.removeClass("active");
      th.parent().find(".showup").slideUp(900);
      $(".main-container").removeClass("black-bg");
    } else {
      let ms = $(".active").length>0 ? 900:0;
      $(".active").removeClass("active");
      $(".showup").slideUp(900);
      $(".main-container").removeClass("black-bg");
      setTimeout(function() {
        th.addClass("active");
        th.parent().find(".showup").slideDown(900);
        $(".main-container").addClass("black-bg");
      }, ms);

    }

  });
  $(".showup").on("click", function(evt) {
    evt.stopPropagation();
  });

});

$(document).on("click", function() {
  $(".active").parent().find(".showup").slideUp(900);
  $(".active").toggleClass("active");
  if ($(".main-container").hasClass("black-bg")) {
    $(".main-container").toggleClass("black-bg");
  }
});

* {
  box-sizing: border-box;
}

body {
  margin: 0;
}

.nav-wrapper {
  width: 100%;
  overflow: hidden;
  background: #424242;
}

nav {
  /*width: 1024px;*/
  margin: auto;
  overflow: hidden;
  background: #424242;
}

.nav-content {
  width: 100%;
  z-index: 999;
  background: #ccc;
}

.top-bar-section {
  float: right;
}

.top-bar-section a.active {
  background: #f00;
}

.showup {
  display: none;
  background: #ccc;
  position: absolute;
  width: 100%;
  top: 70px;
  left: 0;
  z-index: 99;
  padding: 30px 15px 30px 20px;
}

p {
  font-size: 14px;
  line-height: 1.4;
}

li.nav-item {
  display: inline-block;
  background: #f5f5f5;
}

li.nav-item a {
  display: block;
  text-decoration: none;
  padding: 10px;
}

.main-container {
  width: 80%;
  height: 400px;
  margin: auto;
}

.black-bg {
  background: #000;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="nav-wrapper">
  <nav>
    <div class="top-bar-section">
      <ul>
        <li class="nav-item">
          <a href="#" class="click">Nav item 1</a>
          <div class="showup">
            <div class="nav-content">
              <p>
                Dropdown for Nav Item 1.
              </p>
            </div>
          </div>
        </li>
        <li class="nav-item">
          <a href="#" class="click">Nav item 2</a>
          <div class="showup">
            <div class="nav-content">
              <p>
                Dropdown for Nav Item 2.
              </p>
            </div>
          </div>
        </li>
        <li class="nav-item">
          <a href="#" class="click">Nav item 3</a>
          <div class="showup">
            <div class="nav-content">
              <p>
                Dropdown for Nav Item 3.
              </p>
            </div>
          </div>
        </li>
        <li class="nav-item">
          <a href="#" class="click">Nav item 4</a>
          <div class="showup">
            <div class="nav-content">
              <p>
                Dropdown for Nav Item 4.
              </p>
            </div>
          </div>
        </li>
      </ul>
    </div>
  </nav>
</div>
<div class="main-container">

</div>

Answer 2

动画完成后，您需要使用.stop(clearQueue,jumpToEnd)以及slideUp()和slideDown()即complete回调函数的第二个参数来调用，每次匹配时调用一次元件。

你应该首先隐藏所有打开，然后在slideDown的完整回调中调用slideUp，这样一旦打开的菜单完全关闭，就应该打开新的下拉列表。

注意传递给stop()的2个参数，这样当您同时点击时，动画不应继续播放而是跳到显示或隐藏的最后状态

请参阅下面的演示。

＆＃13;

$(document).ready(function() {
  $(".click").on("click", function(e) {
    var menu = $(this);
    toggleDropDown(menu);
  });

  $(document).on('mouseup',function(e) {
    var container = $("nav");

    // if the target of the click isn't the container nor a descendant of the container
    if (!container.is(e.target) && container.has(e.target).length === 0) {
      $('a.active').parent().find('.showup').stop(true, true).slideUp(500, function() {
        $(".main-container").removeClass("black-bg");
        if ($('a.active').hasClass('active')) {
          $('a.active').removeClass('active');
        }
      });
    }
  });

});


function toggleDropDown(menu) {
  var isActive = $('a.active').length;
  $('a.active').parent().find('.showup').stop(true, true).slideUp(500, function() {
    $(".main-container").removeClass("black-bg");
    if (menu.hasClass('active')) {
      menu.removeClass('active');
    } else {
      $('a.active').removeClass('active');
      menu.addClass('active');
      menu.parent().find('.showup').stop(true, true).slideDown(500, function() {
        $(".main-container").addClass("black-bg");
      });
    }
  });
  if (!isActive) {
    menu.addClass('active');
    menu.parent().find('.showup').stop(true, true).slideDown(500, function() {
      $(".main-container").addClass("black-bg");
    });
  }

}

＆＃13;

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-size: 12px;
  font-family: Arial;
}

.nav-wrapper {
  width: 100%;
  overflow: hidden;
  background: #424242;
}

nav {
  width: 100%;
  margin: auto;
  overflow: hidden;
  background: #424242;
}

.nav-content {
  width: 100%;
  z-index: 999;
  background: #ccc;
}

.top-bar-section {
  float: right;
}

.top-bar-section a.active {
  background: #c8c8c8;
  color: #000;
}

.showup {
  display: none;
  background: #ccc;
  position: absolute;
  width: 100%;
  top: 50px;
  left: 0;
  z-index: 99;
  padding: 30px 15px 30px 20px;
}

p {
  font-size: 14px;
  line-height: 1.4;
}

li.nav-item {
  display: inline-block;
  background: #f5f5f5;
}

li.nav-item a {
  display: block;
  text-decoration: none;
  padding: 10px;
}

.main-container {
  width: 80%;
  height: 400px;
  margin: auto;
}

.black-bg {
  background: #000;
}

＆＃13;

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="nav-wrapper">
  <nav>
    <div class="top-bar-section">
      <ul>
        <li class="nav-item">
          <a href="#" class="click">Nav item 1</a>
          <div class="showup">
            <div class="nav-content">
              <p>
                Dropdown for Nav Item 1.
              </p>
            </div>
          </div>
        </li>
        <li class="nav-item">
          <a href="#" class="click">Nav item 2</a>
          <div class="showup">
            <div class="nav-content">
              <p>
                Dropdown for Nav Item 2.
              </p>
            </div>
          </div>
        </li>
        <li class="nav-item">
          <a href="#" class="click">Nav item 3</a>
          <div class="showup">
            <div class="nav-content">
              <p>
                Dropdown for Nav Item 3.
              </p>
            </div>
          </div>
        </li>
        <li class="nav-item">
          <a href="#" class="click">Nav item 4</a>
          <div class="showup">
            <div class="nav-content">
              <p>
                Dropdown for Nav Item 4.
              </p>
            </div>
          </div>
        </li>
      </ul>
    </div>
  </nav>
</div>
<div class="main-container">

</div>

＆＃13;

在打开另一个之前完全关闭下拉列表

2 个答案: