引导下拉菜单落后于小屏幕上的内容

Question

我用引导程序做了一个下拉菜单，但是当我将屏幕调整为小尺寸时，它看起来真的很糟糕，它正常工作，但是当下拉菜单很小时，它开始隐藏在其他内容后面

无论如何，它是否可以放在其他内容之上？

相关的html

<div class="container-fluid no-padding">
  <div class="row">
    <div class="col-xs-12">
      <nav class="navbar navbar-inverse nav-row">
        <a class="navbar-brand" href="#">Locket</a>
        <ul class="nav navbar-nav navbar-right">
          <li class="dropdown">
            <a href="#" class="dropdown-toggle dropdown-display" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">{{currentUser}}</a>

            <ul class="dropdown-menu">
              <li><a href="#">Action</a></li>
              <li><a href="#">Another action</a></li>
              <li><a href="#">Something else here</a></li>
              <li role="separator" class="divider"></li>
              <li><a href="#">Separated link</a></li>
              <li role="separator" class="divider"></li>
              <li ng-click="logout()"><a href="#">Log Out</a></li>
            </ul>
          </li>
        </ul>
      </nav>
    </div>
  </div>

  <div class="row">

    <div class="col-xs-4 friendListWindow">
      <p class="windowTitle text-center">Friends List</p>
      <form class='form-control-inline' ng-submit='addFriend(newFriendUsername)' name='addFriendForm'>
        <div class='form-group'>
          <input autocomplete='off' class='form-control input-display' type='text' name='newFriendUsername' ng-model='newFriendUsername' required/>
          <button class='btn btn-default button-display form-control' type='submit' ng-disabled='!addFriendForm.$valid'><span class="glyphicon glyphicon-plus" aria-hidden="true"></span></button>
        </div>
      </form>

      <span ng-if='sentRequest' class="friendReqSent">{{friendReqMsg}}</span>
      <p class="friendHeaders">Friend Requests</p>
      <div class="friendRequests">
        <ul class="friendList">
          <li class="friendRequest" ng-repeat='friend in friendRequests track by $index'>
            <div class='form-control-inline'>
              <span>New friend request from: {{friend}}</span>
              <div class="friendRequestOptions">
                <button class='btn btn-default friendButton'><span class='glyphicon glyphicon-ok vertical-center' aria-hidden='true' ng-click='acceptFriendRequest(friend)'></span></button>
                <button class='btn btn-default friendButton'><span class='glyphicon glyphicon-remove vertical-center' aria-hidden='true' ng-click='ignoreFriendRequest(friend)'></span></button>
              </div>
            </div>
          </li>
        </ul>
        <div class="acceptedfriendRequests">
          <ul class="friendList">
            <li class="friendRequest" ng-repeat='friend in acceptedfriendRequests track by $index'>
              <span>{{friend}} accepted your friend request</span>
              <button class='btn btn-default friendButton'><span class='glyphicon glyphicon-ok vertical-center' aria-hidden='true' ng-click='acknowledgeFriendRequest(friend)'></span></button>
            </li>
          </ul>
        </div>
      </div>

css:

html, body {
  height: 100%;
  font: 300 16px/22px "Roboto", "Open Sans", "Helvetica Neue", Helvetica, Arial, sans-serif;
}

p {
  margin-left: 10px;
}

ul {
  margin: 0;
}

img {
  width: 100%;
}

.icon {
  max-width: 20px;
  margin: 0;
}

.form-group {
  margin-bottom: 0;
}

.messages {
  padding-bottom: 5px;
}

.message-right {
  text-align: right;
}

.message-left {
  text-align: left;
}

.messageText {
  border-color: transparent;
  border-radius: 15px;
  display: inline-block;
  padding: 6px;
}

.wrapMessage {
  width: 300px;
  word-break: break-word;
  text-align: left;
}

.messageTextFrom {
  background-color: aliceblue;
}

.messageTextTo {
  background-color: beige;
}

.chatWindow {
  height: 95vh;
  padding-left: 0;
}

.friendHeaders {
  font-size: 18px;
  padding-top: 10px;
  margin-left: 10px;
}

.friendSearch {
  width: 60%;
  display: inline;
  vertical-align: middle;
  float:right;
  margin: 8px 13px 5px 5px;
  max-height: 26px;
}

.friendRequests {
  border-bottom: 1px solid lightgray;
}

.friendRequest {
  border-top: 1px solid lightgray;
  padding: 10px;
}

.friendRequestOptions {
  display: inline;
}

.friendListWindow {
  height: 95vh;
  border-right: 1px solid lightgray;
  padding-right: 0;
}

.friendList {
  list-style: none;
  padding-left: 0;
}

.friendPanel {
  border-left: 0px;
  border-right: 0px;
  border-radius: 0px;
  padding: 10px 10px 10px 10px;
  margin-bottom: 0px;
}

.activeFriendPanel {
  background-color: #bfd4d9;
}

.friendArrow {
  float: right;
  color: #ddd;
}

.friendReqSent {
  display: inline-block;
  float: right;
  font-size: 16px;
  padding: 10px;
}

.friendButton {
  display: inline;
  padding: 0 10px 0 10px;
  float: right;
}

.messageList {
  height: 82.5vh;
  overflow: auto;
}

.friendScroll {
  height: 70vh;
  overflow: auto;
}

.dropdown-toggle {
  margin-right: 34px;
  color: #bfd4d9 !important;
}

.navbar {
  position:relative;
  z-index: 1000;
}


.navbar-brand {
  font-family: "Roboto", "Open Sans", "Helvetica Neue", Helvetica, Arial, sans-serif;
  font-weight: bold;
  color: #bfd4d9 !important;
  text-transform: uppercase;
  margin-left: 13px !important;
  font-size: 28px;
}

.unreadMessage {
  display: inline-block;
  background-color: lavender;
  border-radius: 10px;
  padding: 5px;
  color: black;
}

.loginFailed {
  float: left;
  color: white;
  margin-top: 3px;
  margin-right: 8px;
}

img {
  margin-top: 30px;
  margin-left: 24px;
}

.no-padding {
  padding: 0 !important;
  margin: 0 !important;
}

.nav-row {
  margin-bottom: 0px;
  height: 5vh;
  background-color: #252839;
  border-color: #252839;
  border-radius: 0;
}

.form-control-inline {
  min-width: 0;
  width: auto;
  display: inline;
  vertical-align: middle;
  position: relative;
}

.input-display {
  width: 90%;
  display: inline;
  vertical-align: middle;
}

.button-display {
  width: 8%;
  display: inline;
  vertical-align: middle;
  text-align: center;
  border: none;
}

.windowTitle {
  border-bottom: 1px solid lightgray;
  padding: 5px 0px 5px 0px;
  font-size: 18px;
  font-weight: bold;
  margin-left: 0;
}

.btn {
  font-family: "Roboto", "Open Sans", "Helvetica Neue", Helvetica, Arial, sans-serif;
}

.navbar-right {
  margin-right: 0;
  position:relative;
}

.dropdown-display {
  margin-right: 13px;
}

.vertical-center {
  vertical-align: middle;
}

.friendButton {
  width: 8%;
  float: right;
  border: none;
  margin-left: 10px;
  padding-bottom: 5px;
}

.encryptionIndicator {
  display: inline-block;
  float: right;
  padding-right: 10px;
  cursor: pointer;
  font-size: 16px;
}

.encryptionOn {
  color: green;
}

.encryptionOff {
  color: red;
}

Answer 1

您的问题是，在 Bootstrap 中，导航栏上使用的默认下拉菜单在 980 像素以下的屏幕上具有 position: static。

您可以使用 CSS 覆盖样式（并将 no-collapse 类添加到您的 .dropdown-menu。

CSS：

.navbar .dropdown-menu.no-collapse:before {
  left: auto;
  right: 12px;
}
.navbar .dropdown-menu.no-collapse:after {
  left: auto;
  right: 13px;
}
@media (max-width: 979px) {
  .navbar .dropdown-menu.no-collapse {
    background-color: #ffffff;
    border-color: rgba(0, 0, 0, 0.2);
    border-radius: 4px;
    border-style: solid;
    border-width: 1px;
    box-shadow: 0 5px 10px rgba(0, 0, 0, 0.2);
    float: left;
    margin: 0;
    padding: 4px 0;
    position: absolute;
    top: 100%;
  }
  .navbar .dropdown-menu.no-collapse:before,
  .navbar .dropdown-menu.no-collapse:after {
    display: block;
  }
  .navbar .dropdown-menu.no-collapse li + li a {
    margin-bottom: 0;
  }
  .navbar .dropdown-menu.no-collapse .divider {
    display: list-item;
  }
  .navbar .dropdown-menu.no-collapse a {
    border-radius: 0;
    color: #333333;
    font-weight: normal;
    padding: 3px 15px;
  }
  .navbar .dropdown-menu.no-collapse a:hover,
  .navbar .dropdown-menu.no-collapse .active a,
  .navbar .dropdown-menu.no-collapse .active a:hover {
    background-color: #0088cc;
    color: #ffffff;
  }
  .btn-group.open .dropdown-menu.no-collapse {
    display: block;
    margin-top: 1px;
    border-radius: 5px;
  }
}

CODEPEN

Answer 2

因为如果看起来您想让下拉列表在所有视口中可见，您可以在 navbar-header 类中设置下拉列表/链接，然后使用带有navbar-btn 类的按钮下拉列表，这将处理很多框.

.navbar.navbar-custom .navbar-upper {
    position: absolute;
    right: 0px;
}
.navbar.navbar-custom .navbar-upper .dropdown-menu {
    right: 0;
    left: auto;
}

如果您希望它始终位于右侧，您只需要设置一个位置，这样下拉菜单就会在正确的一侧打开，其他一切都只是样式。

/*NEW CSS RULES*/

.navbar.navbar-custom {
  padding-top: 5px;
  padding-bottom: 0;
}
.navbar.navbar-custom .navbar-upper {
  position: absolute;
  right: 0;
}
.navbar.navbar-custom .navbar-upper .dropdown-menu {
  right: 0;
  left: auto;
}
.navbar.navbar-custom .navbar-upper .navbar-btn.btn-drop {
  background: none;
  border: none;
  color: #bfd4d9;
}
.navbar.navbar-custom .navbar-brand {
  font-family: "Roboto", "Open Sans", "Helvetica Neue", Helvetica, Arial, sans-serif;
  font-weight: bold;
  color: #bfd4d9;
  text-transform: uppercase;
  font-size: 28px;
}
/*Original CSS Starts Here*/

html,
body {
  height: 100%;
  font: 300 16px/22px"Roboto", "Open Sans", "Helvetica Neue", Helvetica, Arial, sans-serif;
}
p {
  margin-left: 10px;
}
ul {
  margin: 0;
}
img {
  width: 100%;
}
.icon {
  max-width: 20px;
  margin: 0;
}
.form-group {
  margin-bottom: 0;
}
.messages {
  padding-bottom: 5px;
}
.message-right {
  text-align: right;
}
.message-left {
  text-align: left;
}
.messageText {
  border-color: transparent;
  border-radius: 15px;
  display: inline-block;
  padding: 6px;
}
.wrapMessage {
  width: 300px;
  word-break: break-word;
  text-align: left;
}
.messageTextFrom {
  background-color: aliceblue;
}
.messageTextTo {
  background-color: beige;
}
.chatWindow {
  height: 95vh;
  padding-left: 0;
}
.friendHeaders {
  font-size: 18px;
  padding-top: 10px;
  margin-left: 10px;
}
.friendSearch {
  width: 60%;
  display: inline;
  vertical-align: middle;
  float: right;
  margin: 8px 13px 5px 5px;
  max-height: 26px;
}
.friendRequests {
  border-bottom: 1px solid lightgray;
}
.friendRequest {
  border-top: 1px solid lightgray;
  padding: 10px;
}
.friendRequestOptions {
  display: inline;
}
.friendListWindow {
  height: 95vh;
  border-right: 1px solid lightgray;
  padding-right: 0;
}
.friendList {
  list-style: none;
  padding-left: 0;
}
.friendPanel {
  border-left: 0px;
  border-right: 0px;
  border-radius: 0px;
  padding: 10px 10px 10px 10px;
  margin-bottom: 0px;
}
.activeFriendPanel {
  background-color: #bfd4d9;
}
.friendArrow {
  float: right;
  color: #ddd;
}
.friendReqSent {
  display: inline-block;
  float: right;
  font-size: 16px;
  padding: 10px;
}
.friendButton {
  display: inline;
  padding: 0 10px 0 10px;
  float: right;
}
.messageList {
  height: 82.5vh;
  overflow: auto;
}
.friendScroll {
  height: 70vh;
  overflow: auto;
}
.unreadMessage {
  display: inline-block;
  background-color: lavender;
  border-radius: 10px;
  padding: 5px;
  color: black;
}
.loginFailed {
  float: left;
  color: white;
  margin-top: 3px;
  margin-right: 8px;
}
img {
  margin-top: 30px;
  margin-left: 24px;
}
.no-padding {
  padding: 0 !important;
  margin: 0 !important;
}
.form-control-inline {
  min-width: 0;
  width: auto;
  display: inline;
  vertical-align: middle;
  position: relative;
}
.input-display {
  width: 90%;
  display: inline;
  vertical-align: middle;
}
.button-display {
  width: 8%;
  display: inline;
  vertical-align: middle;
  text-align: center;
  border: none;
}
.windowTitle {
  border-bottom: 1px solid lightgray;
  padding: 5px 0px 5px 0px;
  font-size: 18px;
  font-weight: bold;
  margin-left: 0;
}
.btn {
  font-family: "Roboto", "Open Sans", "Helvetica Neue", Helvetica, Arial, sans-serif;
}
.vertical-center {
  vertical-align: middle;
}
.friendButton {
  width: 8%;
  float: right;
  border: none;
  margin-left: 10px;
  padding-bottom: 5px;
}
.encryptionIndicator {
  display: inline-block;
  float: right;
  padding-right: 10px;
  cursor: pointer;
  font-size: 16px;
}
.encryptionOn {
  color: green;
}
.encryptionOff {
  color: red;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css" rel="stylesheet" />
<nav class="navbar navbar-inverse navbar-static-top navbar-custom">
  <div class="container-fluid">
    <div class="navbar-header"> <a class="navbar-brand" href="#">Locket</a>

      <div class="navbar-upper">
        <div class="btn-group">
          <button type="button" class="btn navbar-btn btn-drop dropdown-toggle" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">{{currentUser}}</button>
          <ul class="dropdown-menu">
            <li><a href="#">Action</a>

            </li>
            <li><a href="#">Another action</a>

            </li>
            <li><a href="#">Something else here</a>

            </li>
            <li role="separator" class="divider"></li>
            <li><a href="#">Separated link</a>

            </li>
            <li role="separator" class="divider"></li>
            <li ng-click="logout()"><a href="#">Log Out</a>

            </li>
          </ul>
        </div>
      </div>
    </div>
  </div>
</nav>
<div class="container">
  <div class="row">
    <div class="col-sm-12 friendListWindow">
      <p class="windowTitle text-center">Friends List</p>
      <form class='form-control-inline' ng-submit='addFriend(newFriendUsername)' name='addFriendForm'>
        <div class='form-group'>
          <input autocomplete='off' class='form-control input-display' type='text' name='newFriendUsername' ng-model='newFriendUsername' required/>
          <button class='btn btn-default button-display form-control' type='submit' ng-disabled='!addFriendForm.$valid'><span class="glyphicon glyphicon-plus" aria-hidden="true"></span>

          </button>
        </div>
      </form> <span ng-if='sentRequest' class="friendReqSent">{{friendReqMsg}}</span>

      <p class="friendHeaders">Friend Requests</p>
      <div class="friendRequests">
        <ul class="friendList">
          <li class="friendRequest" ng-repeat='friend in friendRequests track by $index'>
            <div class='form-control-inline'> <span>New friend request from: {{friend}}</span>

              <div class="friendRequestOptions">
                <button class='btn btn-default friendButton'><span class='glyphicon glyphicon-ok vertical-center' aria-hidden='true' ng-click='acceptFriendRequest(friend)'></span>

                </button>
                <button class='btn btn-default friendButton'><span class='glyphicon glyphicon-remove vertical-center' aria-hidden='true' ng-click='ignoreFriendRequest(friend)'></span>

                </button>
              </div>
            </div>
          </li>
        </ul>
        <div class="acceptedfriendRequests">
          <ul class="friendList">
            <li class="friendRequest" ng-repeat='friend in acceptedfriendRequests track by $index'> <span>{{friend}} accepted your friend request</span>

              <button class='btn btn-default friendButton'><span class='glyphicon glyphicon-ok vertical-center' aria-hidden='true' ng-click='acknowledgeFriendRequest(friend)'></span>

              </button>
            </li>
          </ul>
        </div>
      </div>
    </div>
  </div>
</div>