Study the "Li Yanhui HTML5 Video Tutorial" video tutorial, which will introduce you to HTML5 in detail. HTML5 is the fifth major revision of Hypertext Markup Language (HTML), that is, the latest version; it adds some new features than the original standard. tags to achieve more functions, be more standardized, and be more suitable for mobile Internet.
Video playback address: http://www.php.cn/course/365.html
Difficulties of this course It lies in the new content in HTML5 and the usage of canvas:
Many drawing effects are achieved using canvas, so learning canvas well is the key to learning HTML5 well.
1. Introduction to canvas
1.1 What is canvas?
is an important element in HTML5. Similar to audio and video elements, it can run without any external plug-ins.
The Chinese translation of Canvas is "canvas". It provides powerful graphics. Processing functions (drawing, transformation, pixel processing...).
But it should be noted that the canvas element itself does not draw graphics, it is just equivalent to an empty canvas.
If developers need to draw graphics on the canvas, they must use JavaScript scripts to draw.
1.2 What can canvas do?
Drawing of basic graphics
Drawing of text
Deformation of graphics and synthesis of pictures
Processing of pictures and videos
Animation Implementation
Production of small games
1.3 Supported browsers
Most modern browsers support Canvas, such as Firefox, safari, chrome, and opera recently Versions and IE9 are supported.
IE8 and below do not support HTML5, but we can prompt users to update to the latest version
1.4 Basic concepts about canvas tags
In Defining the canvas element on an HTML page is no different from defining other ordinary elements. In addition to specifying common attributes such as id, style, class, hidden, etc., it can also set the width and height attributes.
Why do you have to say this specifically?
We will explain in detail in Chapter 2.2.
In addition, after we define the canvas element in the web page, it is just a blank canvas. If you want to draw on the canvas, you must go through the following steps.
Get the DOM object corresponding to the canvas element, which must be a canvas object
Call the getContext() method of the canvas object, which returns a canvasRenderingContext2D object, which can draw graphics.
Call the method of canvasRenderingContext2D object to draw.
Then let’s start our canvas practice and see how canvas can draw graphics.
2. Canvas actual combat
2.1 Check the current browser support for canvas
We also explained above that some of our browsers do not support canvas. What should we do at this time?
At this time we can write content directly between the canvas tags. The advantage of this is that when your browser does not support canvas, we can display the content between the tags, as follows.
<!DOCTYPE html> <html> <head> <meta charset="UTF-8" /> <title>Document</title> <style type="text/css"> html,body{ margin: 0px; } canvas{ background: #ccc; } </style> </head> <body> <canvas> 我们在设置 canvas 之前需要首先监测用户电脑是否支持 canvas </canvas> </body> </html>
Now that the specific content has been created, can we see it now?
Although we have not given the width and height of the canvas, our canvas is actually visible on the page.
It should be noted that the width and height of the canvas default style are 300px * 150px.
Even if we do not set the specific width and height, it can still be displayed.
<!DOCTYPE html> <html> <head> <meta charset="UTF-8" /> <title>Document</title> <style type="text/css"> html,body{ margin: 0px; } canvas{ background: #ccc; } </style> </head> <body> <canvas> 我们在设置 canvas 之前需要首先监测用户电脑是否支持 canvas </canvas> </body> </html>
The above is the detailed content of Li Yanhui HTML5 video data sharing. For more information, please follow other related articles on the PHP Chinese website!

html5的div元素默认一行不可以放两个。div是一个块级元素,一个元素会独占一行,两个div默认无法在同一行显示;但可以通过给div元素添加“display:inline;”样式,将其转为行内元素,就可以实现多个div在同一行显示了。

html5中列表和表格的区别:1、表格主要是用于显示数据的,而列表主要是用于给数据进行布局;2、表格是使用table标签配合tr、td、th等标签进行定义的,列表是利用li标签配合ol、ul等标签进行定义的。

固定方法:1、使用header标签定义文档头部内容,并添加“position:fixed;top:0;”样式让其固定不动;2、使用footer标签定义尾部内容,并添加“position: fixed;bottom: 0;”样式让其固定不动。

HTML5中画布标签是“<canvas>”。canvas标签用于图形的绘制,它只是一个矩形的图形容器,绘制图形必须通过脚本(通常是JavaScript)来完成;开发者可利用多种js方法来在canvas中绘制路径、盒、圆、字符以及添加图像等。

html5中不支持的标签有:1、acronym,用于定义首字母缩写,可用abbr替代;2、basefont,可利用css样式替代;3、applet,可用object替代;4、dir,定义目录列表,可用ul替代;5、big,定义大号文本等等。

html5废弃了dir列表标签。dir标签被用来定义目录列表,一般和li标签配合使用,在dir标签对中通过li标签来设置列表项,语法“<dir><li>列表项值</li>...</dir>”。HTML5已经不支持dir,可使用ul标签取代。

html5是指超文本标记语言(HTML)的第五次重大修改,即第5代HTML。HTML5是Web中核心语言HTML的规范,用户使用任何手段进行网页浏览时看到的内容原本都是HTML格式的,在浏览器中通过一些技术处理将其转换成为了可识别的信息。HTML5由不同的技术构成,其在互联网中得到了非常广泛的应用,提供更多增强网络应用的标准机。

因为html5不基于SGML(标准通用置标语言),不需要对DTD进行引用,但是需要doctype来规范浏览器的行为,也即按照正常的方式来运行,因此html5只需要写doctype即可。“!DOCTYPE”是一种标准通用标记语言的文档类型声明,用于告诉浏览器编写页面所用的标记的版本。


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.

ZendStudio 13.5.1 Mac
Powerful PHP integrated development environment

SublimeText3 English version
Recommended: Win version, supports code prompts!

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools
