CSS-layout - Float-eksempler

Indholdsfortegnelse

Vis indholdsfortegnelse

Denne side indeholder almindelige float-eksempler.

Grid of Boxes/Equal Width Boxes

Box 1

Box 2

Box 1

Box 2

Box 3

Med egenskaben float er det nemt at flyde kasser med indhold side om side:

Eksempel

 * {
  box-sizing: border-box;
}
.box {
  float: left;
  width: 33.33%; /* three 
  boxes (use 25% for four, and 50% for two, etc) */
  padding: 
  50px; /* if you want space between the images */
}

Prøv det selv →

<!DOCTYPE html>
<html>
<head>
<style>
* {
  box-sizing: border-box;
}

.box {
  float: left;
  width: 33.33%;
  padding: 50px;
}

.clearfix::after {
  content: "";
  clear: both;
  display: table;
}
</style>
</head>
<body>

<h2>Grid of Boxes</h2>
<p>Float boxes side by side:</p>

<div class="clearfix">
  <div class="box" style="background-color:#bbb">
  <p>Some text inside the box.</p>
  </div>
  <div class="box" style="background-color:#ccc">
  <p>Some text inside the box.</p>
  </div>
  <div class="box" style="background-color:#ddd">
  <p>Some text inside the box.</p>
  </div>
</div>

<p><strong>Note:</strong> Here, we use the clearfix hack to take care of the layout flow. 
We also use the box-sizing property to make sure that the box doesn't break due to extra padding. Try to remove this code to see the effect.</p>

</body>
</html>

Hvad er boksstørrelse?

Du kan nemt lave tre flydende kasser side om side. Men når du tilføjer noget, der forstørrer bredden af hver boks (f.eks. polstring eller kanter), vil boksen gå i stykker. Egenskaben box-sizing giver os mulighed for at inkludere polstring og kant i kassens samlede bredde (og højde), og sørg for, at polstringen forbliver inde i kassen, og at den går ikke i stykker.

Du kan læse mere om kassestørrelsesegenskaben i vores CSS Box Sizing-kapitel.

Billeder Side Om Side

Gitteret af kasser kan også bruges til at vise billeder side om side:

Eksempel

 .img-container {
  float: left;
  width: 33.33%; /* three 
  containers (use 25% for four, and 50% for two, etc) */
  padding: 
  5px; /* if you want space between the images */
}

Prøv det selv →

<!DOCTYPE html>
<html>
<head>
<style>
* {
  box-sizing: border-box;
}

.img-container {
  float: left;
  width: 33.33%;
  padding: 5px;
}

.clearfix::after {
  content: "";
  clear: both;
  display: table;
}
</style>
</head>
<body>

<h2>Images Side by Side</h2>
<p>Float images side by side:</p>

<div class="clearfix">
  <div class="img-container">
  <img src="img_5terre.jpg" alt="Italy" style="width:100%">
  </div>
  <div class="img-container">
  <img src="img_forest.jpg" alt="Forest" style="width:100%">
  </div>
  <div class="img-container">
  <img src="img_mountains.jpg" alt="Mountains" style="width:100%">
  </div>
</div>

<p>Note that we also use the clearfix hack to take care of the layout flow, and that we add the box-sizing property to make sure that the image container doesn't break due to extra padding. Try to remove this code to see the effect.</p>

</body>
</html>

Æsker i lige højde

I det forrige eksempel lærte du at flyde kasser side om side med ens bredde. Det er dog ikke nemt at skabe flydende kasser med lige høje. En hurtig løsning er dog at indstille en fast højde, som i eksemplet nedenfor:

Box 1

Some content, some content, some content

Box 2

Some content, some content, some content

Eksempel

 .box {
  height: 500px;
}

Prøv det selv →

<!DOCTYPE html>
<html>
<head>
<style>
* {
  box-sizing: border-box;
}

.box {
  float: left;
  width: 50%;
  padding: 50px;
  height: 300px;
}

.clearfix::after {
  content: "";
  clear: both;
  display: table;
}
</style>
</head>
<body>

<h2>Equal Height Boxes</h2>
<p>Floating boxes with equal heights:</p>

<div class="clearfix">
  <div class="box" style="background-color:#bbb">
  <h2>Box 1</h2>
  <p>Some content, some content, some content</p>
  </div>
  <div class="box" style="background-color:#ccc">
  <h2>Box 2</h2>
  <p>Some content, some content, some content</p>
  <p>Some content, some content, some content</p>
  <p>Some content, some content, some content</p>
  </div>
</div>

<p>This example not very flexible. It is ok to use CSS height if you can guarantee that the boxes will always have the same amount of content in them, but that's not always the case. If you try the example above on a mobile phone (or resize the browser window), you will see that the second box's content will be displayed outside of the box.</p>
<p>Go back to the tutorial and find another solution, if this is not what you want.</p>

</body>
</html>

Men er dette ikke særlig fleksibelt. Det er ok, hvis du kan garantere, at kasserne altid vil have den samme mængde indhold i sig. Men mange gange er indholdet ikke det samme. Hvis du prøver eksemplet ovenfor på en mobiltelefon, vil du se, at det andet boksens indhold vil blive vist uden for boksen. Det er her, CSS3 Flexbox kommer til nytte - da den automatisk kan strække sig kasser skal være lige så lange som den længste kasse:

Eksempel

Brug Flexbox til at oprette fleksible bokse:

Box 1 - This is some text to make sure that the content gets really tall. This is some text to make sure that the content gets really tall. This is some text to make sure that the content gets really tall.

Box 2 - My height will follow Box 1.

Prøv det selv →

<!DOCTYPE html>
<html>
<head>
<style>
.flex-container {
  display: flex;
  flex-wrap: nowrap;
  background-color: DodgerBlue;
}

.flex-container .box {
  background-color: #f1f1f1;
  width: 50%;
  margin: 10px;
  text-align: center;
  line-height: 75px;
  font-size: 30px;
}
</style>
</head>
<body>

<h1>Flexible Boxes</h1>

<div class="flex-container">
  <div class="box">Box 1 - This is some text to make sure that the content gets really tall. This is some text to make sure that the content gets really tall.</div>
  <div class="box">Box 2 - My height will follow Box 1.</div>
</div>

<p>Try to resize the browser window to see the flexible layout.</p>
<p><strong>Note:</strong> Flexbox is not supported in Internet Explorer 10 or earlier versions.</p>

</body>
</html>

Tip: Du kan læse mere om Flexbox-layoutmodulet i vores CSS Flexbox-kapitel.

Navigationsmenu

Du kan også bruge float med en liste over hyperlinks til at oprette en vandret menu:

Eksempel

Prøv det selv →

<!DOCTYPE html>
<html>
<head>
<style>
ul {
  list-style-type: none;
  margin: 0;
  padding: 0;
  overflow: hidden;
  background-color: #333;
}

li {
  float: left;
}

li a {
  display: inline-block;
  color: white;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
}

li a:hover {
  background-color: #111;
}

.active {
  background-color: red;
}
</style>
</head>
<body>

<ul>
  <li><a href="#home" class="active">Home</a></li>
  <li><a href="#news">News</a></li>
  <li><a href="#contact">Contact</a></li>
  <li><a href="#about">About</a></li>
</ul>

</body>
</html>

Eksempel på weblayout

Det er også almindeligt at lave hele weblayouts ved hjælp af egenskaben float:

Eksempel

 .header, .footer {
  background-color: grey;
  color: white;
    padding: 15px;
}
.column {
  float: left;
  
  padding: 15px;
}
.clearfix::after {
  content: 
  "";
  clear: both;
  display: table;
  }
.menu {
  
  width: 25%;
}
.content {
  width: 75%;
}

Prøv det selv →

<!DOCTYPE html>
<html>
<head>
<style>
* {
  box-sizing: border-box;
}
body {
  background-color: white;
}

.header, .footer {
  background-color: grey;
  color: white;
  padding: 15px;
}

.column {
  float: left;
  padding: 15px;
}

.clearfix::after {
  content: "";
  clear: both;
  display: table;
}

.menu {
  width: 25%;
}

.content {
  width: 75%;
}

.menu ul {
  list-style-type: none;
  margin: 0;
  padding: 0;
}

.menu li {
  padding: 8px;
  margin-bottom: 8px;
  background-color: #33b5e5;
  color: #ffffff;
}

.menu li:hover {
  background-color: #0099cc;
}
</style>
</head>
<body>

<div class="header">
  <h1>Chania</h1>
</div>

<div class="clearfix">
  <div class="column menu">
    <ul>
      <li>The Flight</li>
      <li>The City</li>
      <li>The Island</li>
      <li>The Food</li>
    </ul>
  </div>

  <div class="column content">
    <h1>The City</h1>
    <p>Chania is the capital of the Chania region on the island of Crete. The city can be divided in two parts, the old town and the modern city.</p>
    <p>You will learn more about web layout and responsive web pages in a later chapter.</p>
  </div>
</div>

<div class="footer">
  <p>Footer Text</p>
</div>

</body>
</html>

Flere eksempler

Lad et billede svæve til højre i et afsnit. Tilføj kant og margener til billedet.

Et billede med kant og marginer, der svæver til højre i et afsnit

<!DOCTYPE html>
<html>
<head>
<style>
img {
  float: right;
  border: 1px dotted black;
  margin: 0px 0px 15px 20px;
}
</style>
</head>
<body>

<h2>Let an image float to the right in a paragraph</h2>

<p>In the paragraph below, the image will float to the right. A dotted black border is added to the image. 
We have also added margins to the image to push the text away from the image:
0 px margin on the top and right side, 15 px margin on the bottom, and 20 px margin on the left side of the image.
</p>

<p><img src="w3css.gif" width="100" height="140">
This is some text. This is some text. This is some text.
This is some text. This is some text. This is some text.
This is some text. This is some text. This is some text.
This is some text. This is some text. This is some text.
This is some text. This is some text. This is some text.
This is some text. This is some text. This is some text.
This is some text. This is some text. This is some text.
This is some text. This is some text. This is some text.
This is some text. This is some text. This is some text.
This is some text. This is some text. This is some text.
This is some text. This is some text. This is some text.
This is some text. This is some text. This is some text.
This is some text. This is some text. This is some text.
</p>

</body>
</html>

Lad et billede med en billedtekst flyde til højre.

Et billede med en billedtekst, der svæver til højre

<!DOCTYPE html>
<html>
<head>
<style>
div {
  float: right;
  width: 120px;
  margin: 0 0 15px 20px;
  padding: 15px;
  border: 1px solid black;
  text-align: center;
}
</style>
</head>
<body>

<h2>Let an image with a caption float to the right</h2>

<p>In the paragraph below, the div element is 120 pixels wide and it contains the image. The div element will float to the right. Margins are added to the div to push the text away from the div. Borders and padding are added to the div to frame in the picture and the caption.</p>

<div>
<img src="w3css.gif" width="100" height="140"><br>CSS is fun!
</div>

<p>
This is some text. This is some text. This is some text.
This is some text. This is some text. This is some text.
This is some text. This is some text. This is some text.
This is some text. This is some text. This is some text.
This is some text. This is some text. This is some text.
This is some text. This is some text. This is some text.
This is some text. This is some text. This is some text.
This is some text. This is some text. This is some text.
This is some text. This is some text. This is some text.
This is some text. This is some text. This is some text.
This is some text. This is some text. This is some text.
This is some text. This is some text. This is some text.
This is some text. This is some text. This is some text.
</p>

</body>
</html>

Lad det første bogstav i et afsnit flyde til venstre og stil bogstavet.

Lad det første bogstav i et afsnit flyde til venstre

<!DOCTYPE html>
<html>
<head>
<style>
span {
  float: left;
  width: 0.7em;
  font-size: 400%;
  font-family: algerian, courier;
  line-height: 80%;
}
</style>
</head>
<body>

<h2>Style the first letter of a paragraph and let it float left</h2>

<p>
<span>H</span>ere, the first letter of this text is embedded in a span element. The span element has a width that is 0.7 times the size of the current font. The font-size of the span element is 400% (quite large) and the line-height is 80%. The font of the letter in the span will be in "Algerian".
</p>

</body>
</html>

Brug float til at oprette en hjemmeside med en navbar, sidehoved, sidefod, venstre indhold og hovedindhold.

Oprettelse af en hjemmeside med float

<!DOCTYPE html>
<html>
<head>
<style>
* {
  box-sizing: border-box;
}

body {
  margin: 0;
}

.header {
  background-color: #2196F3;
  color: white;
  text-align: center;
  padding: 15px;
}

.footer {
  background-color: #444;
  color: white;
  padding: 15px;
}

.topmenu {
  list-style-type: none;
  margin: 0;
  padding: 0;
  overflow: hidden;
  background-color: #777;
}

.topmenu li {
  float: left;
}

.topmenu li a {
  display: inline-block;
  color: white;
  text-align: center;
  padding: 16px;
  text-decoration: none;
}

.topmenu li a:hover {
  background-color: #222;
}

.topmenu li a.active {
  color: white;
  background-color: #4CAF50;
}

.column {
  float: left;
  padding: 15px;
}

.clearfix::after {
  content: "";
  clear: both;
  display: table;
}

.sidemenu {
  width: 25%;
}

.content {
  width: 75%;
}

.sidemenu ul {
  list-style-type: none;
  margin: 0;
  padding: 0;
}

.sidemenu li a {
  margin-bottom: 4px;
  display: block;
  padding: 8px;
  background-color: #eee;
  text-decoration: none;
  color: #666;
}

.sidemenu li a:hover {
  background-color: #555;
  color: white;
}

.sidemenu li a.active {
  background-color: #008CBA;
  color: white;
}
</style>
</head>
<body>

<ul class="topmenu">
  <li><a href="#home" class="active">Home</a></li>
  <li><a href="#news">News</a></li>
  <li><a href="#contact">Contact</a></li>
  <li><a href="#about">About</a></li>
</ul>

<div class="clearfix">
  <div class="column sidemenu">
    <ul>
      <li><a href="#flight">The Flight</a></li>
      <li><a href="#city" class="active">The City</a></li>
      <li><a href="#island">The Island</a></li>
      <li><a href="#food">The Food</a></li>
      <li><a href="#people">The People</a></li>
      <li><a href="#history">The History</a></li>
      <li><a href="#oceans">The Oceans</a></li>
    </ul>
  </div>

  <div class="column content">
    <div class="header">
      <h1>The City</h1>
    </div>
    <h1>Chania</h1>
    <p>Chania is the capital of the Chania region on the island of Crete. The city can be divided in two parts, the old town and the modern city.</p>
    <p>You will learn more about responsive web pages in a later chapter.</p>
  </div>
</div>

<div class="footer">
  <p>Footer Text</p>
</div>

</body>
</html>

Alle CSS Float-egenskaber

box-sizing: Definerer, hvordan bredden og højden af et element beregnes: skal de inkludere polstring og kanter, eller ej
clear: Angiver, hvad der skal ske med elementet, der er ved siden af en flydende element
float: Angiver, om et element skal flyde til venstre, højre eller ej alle
overflow: Angiver, hvad der sker, hvis indholdet flyder over et elements boks
overflow-x: Angiver, hvad der skal gøres med venstre/højre kanter af indholdet, hvis det flyder over elementets indholdsområde
overflow-y: Angiver, hvad der skal gøres med de øverste/nederste kanter af indholdet, hvis det flyder over elementets indholdsområde