使图像自适应地引导至导航栏高度

Question

I would like to know how to make an image fit bootstrap navbar height (proportionally), here's a descriptive image:

Any idea?

I'm using this structure:

<nav class="navbar navbar-default">
  <divclass="container-fluid">
    <div class="navbar-header">
      <a class="navbar-brand" href="#">
        <img alt="Brand" src="...">
      </a>
    </div>
  </div>
</nav> 

Answer 1

If you're simply trying to adjust the size of an image to correspond to the height of a default navbar ( min-height: 50px ), simply use the below CSS as a base depending on how you want the image to fit.

In this example, the image will cover it's part of the navbar completely.

See working Snippet.

 body { padding-top: 70px; } .navbar.navbar-inverse { border: none; } .navbar .navbar-brand { padding-top: 0px; } .navbar .navbar-brand img { height: 50px; } 

 <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-fixed-top"> <div class="container-fluid"> <div class="navbar-header"> <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1" aria-expanded="false"> <span class="sr-only">Toggle navigation</span> <span class="icon-bar"></span> <span class="icon-bar"></span> <span class="icon-bar"></span> </button> <a class="navbar-brand" href="#"> <img src="http://placehold.it/350x150/f00/fff"> </a> </div> <div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1"> <ul class="nav navbar-nav"> <li class="active"><a href="#">Link <span class="sr-only">(current)</span></a> </li> <li><a href="#">Link </a> </li> <li><a href="#">Link </a> </li> <li><a href="#">Link </a> </li> <li><a href="#">Link </a> </li> </ul> </div> </div> </nav> <div class="container text-center"> <img src="http://placehold.it/350x150/f00/fff" /> <h4>The Same Image At Full Scale</h4> </div> 

Answer 2

in a previous project of mine I also encountered some issues with this. Here is how I solved the problem:

HTML:

<nav id="myNavbar" class="navbar navbar-inverse navbar-fixed-top" role="navigation">
    <div class="container">
        <div class="navbar-header">
            <button type="button" class="navbar-toggle" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1">
                <span class="sr-only">Toggle navigation</span>
                <span class="icon-bar"></span>
                <span class="icon-bar"></span>
                <span class="icon-bar"></span>
            </button>

            <a class="navbar-brand" href="index.html" class="smoothScroll"><img src="img/logo.png" ondragstart="return false;" alt="logo"/></a>
        </div>

        <div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
            <ul class="nav navbar-nav" >
                <li>
                    <a>Menu Item1</a>
                </li>
            </ul>
        </div>            <!-- /.navbar-collapse -->
    </div>        <!-- /.container -->
</nav>

And the CSS for it:

.navbar-fixed-top {height: 40px;}
.navbar-brand img {height: 40px;}

So setting the navbar and the logo-image to the same height (and not giving it width, thus it will be automatically adjusted) solved the problem for me with good positioning. Two possible cases:

1. you want a fixed navbar:

   .navbar-brand img {position:fixed;right:0;top:0}

2. you want a header on top:

   .navbar-brand img {position:absolute;right:0;top:0}

In both cases I set it to top-right corner of the site, but you can adjust that easily. So the key is: same height navbar and image, with the image positioned well . (Then margin-padding or exact position of the image can easily be set in CSS)

Hope it helped, Andrew

EDIT: Regarding fixed navbar please check the Bootstrap documentation (it has built-in class like navbar-fixed-top and such).