html - 删除 Flexbox 时垂直居中失败

Question

我不确定为什么会这样。当我删除时:

.nav-username {
    display: flex;
    align-items: center;
}

元素水平对齐，但是，图像和文本不再垂直对齐，因为我删除了 display: flex 和 align-items: center。

$('.dropdown').on('click', function() {
  $('.navigation-ul li:not(:first-child)').toggleClass('active');
});

*,
*:after,
*:before {
  margin: 0;
  padding: 0;
  -webkit-box-sizing: border-box;
  box-sizing: border-box;
  text-decoration: none;
  color: white;
}

a {
  color: #f1f1f1;
}

html {
  font-size: 16px;
}

body {
  background-color: #fafafa;
  font-family: 'Roboto', sans-serif;
  height: 100%;
  width: 100%;
}

.navigation {
  background-color: #171717;
}

.navigation-ul {
  display: flex;
  align-items: center;
}

.navigation-ul>li:not(.dropdown) {
  padding: 10px 15px 10px 15px;
  font-weight: 500;
  text-align: center;
  font-size: 1em;
  color: white;
  background-color: #151719;
  list-style-type: none;
}

.navigation-ul li:nth-last-child(2) {
  margin-left: auto;
}

.nav-username {
  display: flex;
  align-items: center;
}

.profile-picture {
  display: inline-block;
  border-radius: 50px;
  height: 30px;
  width: 30px;
  margin-right: 10px;
}

@media all and (min-width: 0px) and (max-width: 1200px) {
  .navigation-ul {
    flex-wrap: wrap;
  }
  .navigation-ul>li {
    flex: 1 1 100%;
  }
}

@media screen and (max-width: 1200px) {
  .navigation-ul li:first-child {
    display: block;
  }
  .navigation-ul li {
    display: none;
  }
  .navigation-ul li.active {
    display: block;
  }
  .navigation-ul .dropdown {
    display: block;
    cursor: pointer;
  }
  .home-container {
    columns: 2;
  }
  .dropdown {
    padding: 7px 0 7px 0;
    text-align: center;
  }
  .specific-image-flexbox {
    flex-direction: column;
  }
}

@media screen and (max-width: 600px) {
  .home-container {
    columns: 1;
  }
  .category-container-element {
    width: 100%;
  }
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<nav class='navigation'>
  <div class="wrapper">
    <ul class="navigation-ul">
      <li class='dropdown'>Dropdown</li>
      <li><a href="">Images</a></li>
      <li><a href="">Categories</a></li>
      <li><a href="">Upload</a></li>
      <li>
        <a class='nav-username' href=''>
          <img class='profile-picture' src=''> Username
        </a>
      </li>
      <li><a href="">Logout</a></li>
    </ul>
  </div>
</nav>

Answer 1

您还需要添加属性 justify-content:center;。因此它将在垂直和水平方向上居中对齐。

所以，你需要更新

.nav-username {
    display: flex;
    align-items: center;
}

到

.nav-username {
    display: flex;
    align-items: center;
    justify-content: center;
}