Home Web Front-end JS Tutorial How to use JS to determine whether the current page has scroll bars

How to use JS to determine whether the current page has scroll bars

Apr 08, 2018 am 09:23 AM
javascript page

This time I will show you how to use JS to determine whether the current page has scroll bars, and how to use JS to determine whether the current page has scroll bars. What are the precautions?The following is a practical case, let's take a look. .

Preface

Recently in the process of writing a plug-in, I need to use JS to determine whether there is a scroll bar. After searching, the general methods are similar, but they are all a bit verbose. The code is not concise enough. Finally, by referring to different methods, I wrote a relatively simple method. When judging the scroll bar, you also need to calculate the width of the scroll bar. I will share it with you through this article.

Why should we judge the scroll bar

The need to judge the scroll bar is often used in pop-up window plug-ins, because most pop-up windows will add <a href="http://www.php.cn/wiki/923.html" target="_blank">overflow</a>: hidden attribute. If the page is relatively long, the page will shake after adding this attribute.

In order to enhance the user experience, add the <a href="http://www.php.cn/wiki/937.html" target="_blank">margin-left</a> attribute to offset the scroll bar after overflow: hidden by determining whether there is a scroll bar. Location.

How to determine whether there is a scroll bar

In fact, only one line of JS is needed. The test is compatible with IE7

function hasScrollbar() {
  return document.body.scrollHeight > (window.innerHeight || document.documentElement.clientHeight);
}
Copy after login

Generally, use document.body.scrollHeight > window.innerHeight can be judged.

But in IE7 and IE8, window.innerHeight is underfined, so in order to be compatible with IE7 and IE8, you need to use document.documentElement.clientHeight Property calculates window height.

The method of calculating the scroll bar width

still takes the pop-up window as an example, because the scroll bars of IE 10 and above and mobile browsers do not occupy the page width. Transparent style (IE 10 and above browsers can restore the original scroll bar style through CSS properties), so in order to further enhance the user experience, we also need to calculate the width of the scroll bar and add a reasonable margin-left ## according to the situation. #Value.

The method to calculate the width of the scroll bar is relatively simple. Create a new p element with a scroll bar and pass the

offsetWidth and clientWidth of the element. The difference of can be obtained. I will learn from the method in Magnific-popup

function getScrollbarWidth() {
  var scrollp = document.createElement("p");
  scrollp.style.cssText = 'width: 99px; height: 99px; overflow: scroll; position: absolute; top: -9999px;';
  document.body.appendChild(scrollp);
  var scrollbarWidth = scrollp.offsetWidth - scrollp.clientWidth;
  document.body.removeChild(scrollp);
  return scrollbarWidth;
}
Copy after login

I believe you have mastered the method after reading the case in this article. For more exciting content, please pay attention to other related articles on the php Chinese website!

Recommended reading:

Detailed explanation of the steps of interaction between Ajax() and the background

How to use Ajax in Django

The above is the detailed content of How to use JS to determine whether the current page has scroll bars. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
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

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

How to copy a page in Word How to copy a page in Word Feb 20, 2024 am 10:09 AM

Want to copy a page in Microsoft Word and keep the formatting intact? This is a smart idea because duplicating pages in Word can be a useful time-saving technique when you want to create multiple copies of a specific document layout or format. This guide will walk you through the step-by-step process of copying pages in Word, whether you are creating a template or copying a specific page in a document. These simple instructions are designed to help you easily recreate your page without having to start from scratch. Why copy pages in Microsoft Word? There are several reasons why copying pages in Word is very beneficial: When you have a document with a specific layout or format that you want to copy. Unlike recreating the entire page from scratch

How to implement an online speech recognition system using WebSocket and JavaScript How to implement an online speech recognition system using WebSocket and JavaScript Dec 17, 2023 pm 02:54 PM

How to use WebSocket and JavaScript to implement an online speech recognition system Introduction: With the continuous development of technology, speech recognition technology has become an important part of the field of artificial intelligence. The online speech recognition system based on WebSocket and JavaScript has the characteristics of low latency, real-time and cross-platform, and has become a widely used solution. This article will introduce how to use WebSocket and JavaScript to implement an online speech recognition system.

WebSocket and JavaScript: key technologies for implementing real-time monitoring systems WebSocket and JavaScript: key technologies for implementing real-time monitoring systems Dec 17, 2023 pm 05:30 PM

WebSocket and JavaScript: Key technologies for realizing real-time monitoring systems Introduction: With the rapid development of Internet technology, real-time monitoring systems have been widely used in various fields. One of the key technologies to achieve real-time monitoring is the combination of WebSocket and JavaScript. This article will introduce the application of WebSocket and JavaScript in real-time monitoring systems, give code examples, and explain their implementation principles in detail. 1. WebSocket technology

How to use JavaScript and WebSocket to implement a real-time online ordering system How to use JavaScript and WebSocket to implement a real-time online ordering system Dec 17, 2023 pm 12:09 PM

Introduction to how to use JavaScript and WebSocket to implement a real-time online ordering system: With the popularity of the Internet and the advancement of technology, more and more restaurants have begun to provide online ordering services. In order to implement a real-time online ordering system, we can use JavaScript and WebSocket technology. WebSocket is a full-duplex communication protocol based on the TCP protocol, which can realize real-time two-way communication between the client and the server. In the real-time online ordering system, when the user selects dishes and places an order

How to quickly refresh a web page? How to quickly refresh a web page? Feb 18, 2024 pm 01:14 PM

Page refresh is very common in our daily network use. When we visit a web page, we sometimes encounter some problems, such as the web page not loading or displaying abnormally, etc. At this time, we usually choose to refresh the page to solve the problem, so how to refresh the page quickly? Let’s discuss the shortcut keys for page refresh. The page refresh shortcut key is a method to quickly refresh the current web page through keyboard operations. In different operating systems and browsers, the shortcut keys for page refresh may be different. Below we use the common W

How to implement an online reservation system using WebSocket and JavaScript How to implement an online reservation system using WebSocket and JavaScript Dec 17, 2023 am 09:39 AM

How to use WebSocket and JavaScript to implement an online reservation system. In today's digital era, more and more businesses and services need to provide online reservation functions. It is crucial to implement an efficient and real-time online reservation system. This article will introduce how to use WebSocket and JavaScript to implement an online reservation system, and provide specific code examples. 1. What is WebSocket? WebSocket is a full-duplex method on a single TCP connection.

How to Rearrange, Disable, and Delete iPhone Home Screen Pages How to Rearrange, Disable, and Delete iPhone Home Screen Pages Nov 29, 2023 am 08:22 AM

In iOS, Apple allows you to disable individual home screen pages on your iPhone. It's also possible to rearrange the order of home screen pages and delete pages directly instead of just disabling them. Here's how it works. How to Rearrange Home Screen Pages Touch and hold Space on the Home screen to enter jitter mode. Tap the row of dots that represent Home screen pages. In the Home screen grid that appears, touch and drag a page to rearrange it relative to other pages. Others move in response to your dragging. When you're happy with your new arrangement, tap "Done" in the upper right corner of the screen, then tap "Done" again to exit dither mode. How to Disable or Remove Home Screen Pages Touch and hold Space on the Home screen to enter dither mode. Tap to represent home screen

How to implement page jump in 3 seconds: PHP Programming Guide How to implement page jump in 3 seconds: PHP Programming Guide Mar 25, 2024 am 10:42 AM

Title: Implementation method of page jump in 3 seconds: PHP Programming Guide In web development, page jump is a common operation. Generally, we use meta tags in HTML or JavaScript methods to jump to pages. However, in some specific cases, we need to perform page jumps on the server side. This article will introduce how to use PHP programming to implement a function that automatically jumps to a specified page within 3 seconds, and will also give specific code examples. The basic principle of page jump using PHP. PHP is a kind of

See all articles