Bootstrap 4折叠导航栏背景颜色

Question

我想在 bootstrap 4 alpha v6 中更改折叠导航栏的背景颜色。当然我想改变整个导航栏的背景颜色。

所以问题是任何负责导航栏崩溃的类？到目前为止我发现的唯一div是#navbarSupportedContent，但它只是导航栏中ul的内容（所以它不会改变整个导航栏的颜色）。我可以检查jquery是否折叠导航栏然后更改背景颜色，但我想知道我是否可以在css中完成它。

除此之外，我想说导航栏的默认颜色是透明的，这就是为什么我要在它崩溃时更改它的颜色。

我接下来还要问一下BS4中负责导航栏切换器图标的类是什么？我问，因为我想改变图标的​​颜色。我已经找到并尝试了以下内容：

.navbar-toggler-icon {
  color:white !important;
}

Answer 1

也适用于v4。

这里有一个 Bootstrap 4 alpha6 CSS演练，涵盖.navbar本身，内部链接和汉堡按钮的修改（所有这些都应该使用!important 仅作为最后覆盖度假村）：

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/* change navbar background */
nav.navbar {
  background: transparent;
}
/* change navbar-brand color */
.navbar a.navbar-brand {
  color: white;
}
/* change navbar-brand color on hover */
.navbar a.navbar-brand:hover {
  color: green;
}
/*  change navbar li colors, also active one but not disabled one */
.navbar ul.navbar-nav li.nav-item a.nav-link {
  color: white;
}
/* change navbar-toggler inside lines color (stroke) */
.navbar-light span.navbar-toggler-icon {
  background-image: url("data:image/svg+xml;charset=utf8,%3Csvg viewBox='0 0 32 32' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath stroke='yellow' stroke-width='2' stroke-linecap='round' stroke-miterlimit='10' d='M4 8h24M4 16h24M4 24h24'/%3E%3C/svg%3E");
  color: white;
}
/* change hamburger button border color */
button.navbar-toggler.navbar-toggler-right {
  border-color: yellow;
}
/* change navbar background on collapse */
@media (max-width: 768px) {
  nav.navbar {
    background: lightgray;
  }
}

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<link href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/css/bootstrap.min.css" rel="stylesheet" />
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/tether/1.3.7/js/tether.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/js/bootstrap.min.js" integrity="sha384-vBWWzlZJ8ea9aCX4pEW3rVHjgjt7zpkNpZk+02D9phzyeVkE+jo0ieGizqPLForn" crossorigin="anonymous"></script>
<nav class="navbar navbar-toggleable-md navbar-light">
  <button class="navbar-toggler navbar-toggler-right" type="button" data-toggle="collapse" data-target="#navbarTogglerDemo02" aria-controls="navbarTogglerDemo02" aria-expanded="false" aria-label="Toggle navigation">
    <span class="navbar-toggler-icon"></span>
  </button>
  <a class="navbar-brand" href="#">Navbar</a>
  <div class="collapse navbar-collapse" id="navbarTogglerDemo02">
    <ul class="navbar-nav mr-auto mt-2 mt-md-0">
      <li class="nav-item active">
        <a class="nav-link" href="#">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">
        <a class="nav-link disabled" href="#">Disabled</a>
      </li>
    </ul>
    <form class="form-inline my-2 my-lg-0">
      <input class="form-control mr-sm-2" type="text" placeholder="Search">
      <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
    </form>
  </div>
</nav>

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Answer 2

  

” ...但是情况是，我开头的背景色是   透明的，然后如果有人将其折叠，则背景   颜色应该改变。”

我确实这样：

<style>
.navbar { 
    background-color: transparent;
}
.navbar.collapse {
    display:flex;
}
.navbar.collapsing,
.navbar.show {
    background:white !important;
}
</style>



<nav class="navbar navbar-light navbarSupportedContent">
    <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 navbarSupportedContent">
   </div>
</nav>

Answer 3

这是我的工作方式：

    .navbar-collapse {
    background-color: white;
}