Implementation of absolute positioning reference method-CSS Tutorial-php.cn

Home

Web Front-end

CSS Tutorial

Implementation of absolute positioning reference method

王林

Jan 23, 2024 am 08:58 AM

accomplishabsolute positioningReference method

Implementation of absolute positioning reference method

The reference method to achieve absolute positioning requires specific code examples

With the continuous development of web development, the requirements for page layout are getting higher and higher. Absolute positioning is a common layout method that accurately specifies the position of an element on the page. This article will introduce how to achieve absolute positioning through CSS and provide specific code examples.

1. Understand the basic concepts of absolute positioning

Before you start writing code, you first need to understand the basic concepts of absolute positioning. In CSS, absolute positioning determines the position of an element relative to the nearest parent element that has a positioning attribute (the position attribute is not static). If no parent element has a positioning attribute, the element's position will be positioned relative to the browser window.

2. Basic absolute positioning code example

The following is a simple HTML structure example:

<!DOCTYPE html>
<html>
<head>
<style>
#container {
  position: relative;
  width: 400px;
  height: 300px;
}

#box {
  position: absolute;
  top: 50px;
  left: 50px;
  width: 200px;
  height: 150px;
  background-color: red;
}
</style>
</head>
<body>

<div id="container">
  <div id="box"></div>
</div>

</body>
</html>

In the above example, we created a parent element container and A child element box. The parent element container uses the position: relative attribute, and the child element box uses the position: absolute attribute. And determine the position and size of the sub-element box through the top, left, width and height attributes.

3. Reference method to achieve absolute positioning

In actual development, it is sometimes necessary to use different reference objects to achieve absolute positioning. Two commonly used methods will be introduced here, one is to use the parent element as the reference object, and the other is to use the page boundary as the reference object.

Use the parent element as a reference to achieve absolute positioning

<!DOCTYPE html>
<html>
<head>
<style>
.parent {
  position: relative;
  width: 500px;
  height: 300px;
  border: 1px solid #000;
}

.child {
  position: absolute;
  top: 50px;
  left: 50px;
  width: 200px;
  height: 100px;
  background-color: red;
}
</style>
</head>
<body>

<div class="parent">
  <div class="child"></div>
</div>

</body>
</html>

In the above code example, we created a parent container parent and a child element child. The parent container parent uses the position: relative attribute, and the child element child uses the position: absolute attribute. Use the top and left attributes to determine the position of the child element relative to the parent container parent.

Use the page boundary as a reference to achieve absolute positioning

<!DOCTYPE html>
<html>
<head>
<style>
.container {
  position: relative;
  width: 500px;
  height: 300px;
  border: 1px solid #000;
}

.box {
  position: absolute;
  top: 50px;
  left: calc(50% - 100px);
  width: 200px;
  height: 100px;
  background-color: red;
}
</style>
</head>
<body>

<div class="container">
  <div class="box"></div>
</div>

</body>
</html>

In the above code example, we created a container container and an element box. The container container uses the position: relative attribute, and the element box uses the position: absolute attribute. Use the top and left attributes to determine the position of the element box relative to the page boundary. In this example, we use the calc() function to achieve horizontal centering, where calc(50% - 100px) means that the distance between the left side of the element box and the left edge of the page is 50% of the page width minus half the box width.

Summary:

Through the examples of the above two methods, we can achieve absolute positioning using the parent element or page boundary as a reference. These methods are very practical in page layout, and can give full play to the advantages of absolute positioning and accurately control the placement of elements. I hope the introduction in this article can help you.

The above is the detailed content of Implementation of absolute positioning reference method. For more information, please follow other related articles on the PHP Chinese website!

Statement

The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Anchor Positioning Just Don't Care About Source OrderApr 29, 2025 am 09:37 AM

The fact that anchor positioning eschews HTML source order is so CSS-y because it's another separation of concerns between content and presentation.

What does margin: 40px 100px 120px 80px signify?Apr 28, 2025 pm 05:31 PM

Article discusses CSS margin property, specifically "margin: 40px 100px 120px 80px", its application, and effects on webpage layout.

What are the different CSS border properties?Apr 28, 2025 pm 05:30 PM

The article discusses CSS border properties, focusing on customization, best practices, and responsiveness. Main argument: border-radius is most effective for responsive designs.

What are CSS backgrounds, list the properties?Apr 28, 2025 pm 05:29 PM

The article discusses CSS background properties, their uses in enhancing website design, and common mistakes to avoid. Key focus is on responsive design using background-size.

What are CSS HSL Colors?Apr 28, 2025 pm 05:28 PM

Article discusses CSS HSL colors, their use in web design, and advantages over RGB. Main focus is on enhancing design and accessibility through intuitive color manipulation.

How can we add comments in CSS?Apr 28, 2025 pm 05:27 PM

The article discusses the use of comments in CSS, detailing single-line and multi-line comment syntaxes. It argues that comments enhance code readability, maintainability, and collaboration, but may impact website performance if not managed properly.

What are CSS Selectors?Apr 28, 2025 pm 05:26 PM

The article discusses CSS Selectors, their types, and usage for styling HTML elements. It compares ID and class selectors and addresses performance issues with complex selectors.

Which type of CSS holds the highest priority?Apr 28, 2025 pm 05:25 PM

The article discusses CSS priority, focusing on inline styles having the highest specificity. It explains specificity levels, overriding methods, and debugging tools for managing CSS conflicts.

See all articles