如何在bootstrap导航栏下拉菜单中添加右上箭头

Question

How do I make the arrow in the middle of dropdown menu go to the right exactly under the gear-icon ?

Screenshot

CSS

.dropdown-menu > li > a {
    /*     border-bottom: 1px solid #DDDDDD; */
    padding: 8px 20px;
    color: #333333;
}
.dropdown-menu > li:first-child > a{
    border-radius: 10px 10px 0 0;
}
.dropdown-menu > li:last-child > a{
    border-bottom: 0 none;
    border-radius: 0 0 10px 10px;
}
.dropdown-menu > li > a:hover, .dropdown-menu > li > a:focus {
    background-color: #F5F5F5;
    color: #333333;
    opacity: 1;
    text-decoration: none;
}
.navbar-toggle{
    margin-top: 19px;
    margin-bottom: 19px;
    border: 0;
}
.navbar-toggle .icon-bar {
    background-color: #FFFFFF;
}
.navbar-collapse, .navbar-form {
    border-color: rgba(0, 0, 0, 0);
}
.navbar-default .navbar-toggle:hover, .navbar-default .navbar-toggle:focus {
    background-color: rgba(0,0,0,0);
}


@media (min-width: 768px){
    .navbar-form {
        margin-top: 21px;
        margin-bottom: 21px;
        padding-left: 5px;
        padding-right: 5px;
    }
    .navbar-search-form{
        display: none;
    }
    .navbar-nav > li > .dropdown-menu, .dropdown-menu{
        display: block;
        margin: 0;
        padding: 0;
        z-index: 9000;
        position: absolute;
        -webkit-border-radius: 10px;
        box-shadow: 1px 2px 3px rgba(0, 0, 0, 0.125);
        border-radius: 10px;
        -webkit-box-sizing: border-box;
        -moz-box-sizing: border-box;
        box-sizing: border-box;
        opacity: 0;
        -ms-filter: "alpha(opacity=0)";
        -webkit-filter: alpha(opacity=0);
        -moz-filter: alpha(opacity=0);
        -ms-filter: alpha(opacity=0);
        -o-filter: alpha(opacity=0);
        filter: alpha(opacity=0);
        -webkit-transform: scale(0);
        -moz-transform: scale(0);
        -o-transform: scale(0);
        -ms-transform: scale(0);
        transform: scale(0);
        -webkit-transition: all 300ms cubic-bezier(0.34, 1.61, 0.7, 1);
        -moz-transition: all 300ms cubic-bezier(0.34, 1.61, 0.7, 1);
        -o-transition: all 300ms cubic-bezier(0.34, 1.61, 0.7, 1);
        -ms-transition: all 300ms cubic-bezier(0.34, 1.61, 0.7, 1);
        transition: all 300ms cubic-bezier(0.34, 1.61, 0.7, 1);

    }
    .navbar-nav > li.open > .dropdown-menu, .open .dropdown-menu{
        -webkit-transform-origin: 29px -50px;
        -moz-transform-origin: 29px -50px;
        -o-transform-origin: 29px -50px;
        -ms-transform-origin: 29px -50px;
        transform-origin: 29px -50px;
        -webkit-transform: scale(1);
        -moz-transform: scale(1);
        -o-transform: scale(1);
        -ms-transform: scale(1);
        transform: scale(1);
        opacity: 1;
        -ms-filter: none;
        -webkit-filter: none;
        -moz-filter: none;
        -ms-filter: none;
        -o-filter: none;
        filter: none;
    }
    .dropdown-menu:before{
        border-bottom: 11px solid rgba(0, 0, 0, 0.2);
        border-left: 11px solid rgba(0, 0, 0, 0);
        border-right: 11px solid rgba(0, 0, 0, 0);
        content: "";
        display: inline-block;
        position: absolute;
        left: 100%;
        margin-left: -60%;
        top: -11px;
    }
    .dropdown-menu:after {
        border-bottom: 11px solid #FFFFFF;
        border-left: 11px solid rgba(0, 0, 0, 0);
        border-right: 11px solid rgba(0, 0, 0, 0);
        content: "";
        display: inline-block;
        position: absolute;
        left: 100%;
        margin-left: -60%;
        top: -10px;
    }
}

HTML

<li ng-if="authCheck">
     <a href="#" data-toggle="dropdown" class="dropdown-toggle" title="Settings"><i class="ionicon ion-gear-b"></i></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 class="divider"></li>

                    <li><a href="#">Separated link</a></li>

                    <li class="divider"></li>

                    <li><a href="#">One more separated link</a></li>

                </ul>
            </li>
        </ul>

  </li>

Answer 1

You have to edit the position of the :before & :after selectors.

.dropdown-menu:before {
  position: absolute;
  top: -7px;
  left: 9px; /* Example: right:10px; */
  display: inline-block;
  border-right: 7px solid transparent;
  border-bottom: 7px solid #ccc;
  border-left: 7px solid transparent;
  border-bottom-color: rgba(0, 0, 0, 0.2);
  content: '';
}

.dropdown-menu:after {
  position: absolute;
  top: -6px;
  left: 10px; /* Example: right:10px; */
  display: inline-block;
  border-right: 6px solid transparent;
  border-bottom: 6px solid #ffffff;
  border-left: 6px solid transparent;
  content: '';
}

In your case you will have to change the left property to right and play with the value in pixels in order to position the arrow right below the icon.

DEMO