搜索框引导程序 4 无法定位在导航栏中的中间

Question

我试图将我的搜索栏放在导航栏的中间。左边有标志，右边有菜单。我哪里出错了，我该如何解决这个问题。

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css">


<nav class="navbar navbar-expand-lg navbar-light bg-light mb-4">
  <div class="container-fluid">
    <a class="navbar-brand" href="{% url 'home' %}">ATG</a>
    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
            <span class="navbar-toggler-icon"></span>
          </button>

    <div class="collapse navbar-collapse justify-content-end" id="navbarSupportedContent">
      <ul class="navbar-nav">
        <li class="nav-item active">
          <a class="nav-link" href="{% url 'home' %}">Home <span class="sr-only">(current)</span></a>
        </li>
        <li class="nav-item">
          <a class="nav-link" href="#">Link</a>
        </li>
        <li class="nav-item dropdown">
          <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
                  More
                </a>
          <div class="dropdown-menu" aria-labelledby="navbarDropdown">
            {% if not user.is_authenticated %}
            <a class="dropdown-item" href="{% url 'signup' %}">Sign up</a>
            <a class="dropdown-item" href="{% url 'login' %}">Log in</a> {% else %}
            <a class="dropdown-item" href="{% url 'secret' %}">Profile</a>
            <a class="dropdown-item" href="{% url 'password_change' %}">Change password</a>
            <div class="dropdown-divider"></div>
            <a class="dropdown-item" href="{% url 'logout' %}">Log out</a> {% endif %}
          </div>
        </li>
      </ul>
      <form class="navbar-form" id="search" role="search">
        <div class="form-group">
          <input type="text" class="form-control" placeholder="Search">
        </div>
        <!-- <button type="submit" class="btn btn-default">Submit</button> -->
      </form>
      <style>
        #search {
          text-align: center;
        }
      </style>
    </div>
  </div>
</nav>

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.3/umd/popper.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.1.3/js/bootstrap.min.js"></script>

这是fiddle的链接

Answer 1

希望对您有所帮助。

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js"></script>


<nav class="navbar navbar-expand-lg navbar-light bg-light mb-4">
    <div class="container-fluid">
      <a class="navbar-brand" href="{% url 'home' %}">ATG</a>
      <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
        <span class="navbar-toggler-icon"></span>
      </button>

      <div class="collapse navbar-collapse justify-content-end" id="navbarSupportedContent">
          
        <ul class="navbar-nav">
          <li class="nav-item active">
            <a class="nav-link" href="{% url 'home' %}">Home <span class="sr-only">(current)</span></a>
          </li>
          <li class="nav-item">
            <a class="nav-link" href="#">Link</a>
          </li>
          <li class="nav-item dropdown">
            <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
              More
            </a>
            <div class="dropdown-menu" aria-labelledby="navbarDropdown">
              {% if not user.is_authenticated %}
              <a class="dropdown-item" href="{% url 'signup' %}">Sign up</a>
              <a class="dropdown-item" href="{% url 'login' %}">Log in</a>
              {% else %}
                <a class="dropdown-item" href="{% url 'secret' %}">Profile</a>
                <a class="dropdown-item" href="{% url 'password_change' %}">Change password</a>
                <div class="dropdown-divider"></div>
                <a class="dropdown-item" href="{% url 'logout' %}">Log out</a>
              {% endif %}
            </div>
          </li>
        </ul>
      <form class="navbar-form col-lg-4 mx-lg-auto order-lg-first mb-0" id="search" role="search">
                               <div class="form-group mb-0">
                                   <input type="text" class="form-control" placeholder="Search">
                               </div>
                               <!-- <button type="submit" class="btn btn-default">Submit</button> -->
                           </form>
   
      </div>
    </div>
  </nav>

Answer 2

您的表单需要将 mx-auto 类水平居中。

我也添加了form-inline，这样搜索框和按钮就在一行了。您可以查看 full list of Bootstrap 4 classes 了解更多信息。

.navbar-form input[type=text] {
  border-top-right-radius: 0 !important;
  border-bottom-right-radius: 0 !important;
}

.navbar-form button {
  border-top-left-radius: 0 !important;
  border-bottom-left-radius: 0 !important;
}

<link href="https://stackpath.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css" rel="stylesheet" />
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css">

<nav class="navbar navbar-expand-lg navbar-light bg-light mb-4">
  <div class="container-fluid">
    <a class="navbar-brand" href="{% url 'home' %}">ATG</a>

    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
			<span class="navbar-toggler-icon"></span>
		</button>

    <div class="collapse navbar-collapse justify-content-end" id="navbarSupportedContent">

      <form class="navbar-form form-inline mx-auto my-0" id="search" role="search">
        <div class="form-group w-100">
          <input type="text" class="form-control" placeholder="Search">
          <button type="submit" class="btn btn-default"><i class="fa fa-search"></i></button>
        </div>
      </form>

      <ul class="navbar-nav">
        <li class="nav-item active">
          <a class="nav-link" href="{% url 'home' %}">Home <span class="sr-only">(current)</span></a>
        </li>
        <li class="nav-item">
          <a class="nav-link" href="#">Link</a>
        </li>
        <li class="nav-item dropdown">
          <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">More</a>
          <div class="dropdown-menu" aria-labelledby="navbarDropdown">
            {% if not user.is_authenticated %}
            <a class="dropdown-item" href="{% url 'signup' %}">Sign up</a>
            <a class="dropdown-item" href="{% url 'login' %}">Log in</a> {% else %}
            <a class="dropdown-item" href="{% url 'secret' %}">Profile</a>
            <a class="dropdown-item" href="{% url 'password_change' %}">Change password</a>
            <div class="dropdown-divider"></div>
            <a class="dropdown-item" href="{% url 'logout' %}">Log out</a> {% endif %}
          </div>
        </li>
      </ul>
    </div>
  </div>
</nav>

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.3/umd/popper.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.1.3/js/bootstrap.min.js"></script>