How to use html5

With the popularity of mobile devices and the rapid development of the Internet, HTML5 has recently become an important topic in the Internet world. HTML5 is the fifth version of HTML (Hyper Text Markup Language). Its release triggered the biggest browser change in the past decade. HTML5 not only expands the functionality of web applications, but also reduces numerous security vulnerabilities. So, how is HTML5 specifically used in actual project development? This article will give you a detailed introduction in a concise and easy-to-understand way.

1. Application of HTML5

HTML5's support for browsers and its impact on traditional Web applications have become hot topics discussed by many Web developers. HTML5 provides built-in multimedia support for browsers and adds tags and plug-ins. In this way, applications opened through the browser can also use audio, video, graphics, positioning, etc. At the same time, the functions supported by HTML5 web client technology include verification, programming support, semantic markup, multimedia, offline access, graphics access, preloading, etc., all of which play an active role in Web development.

1. Multimedia support: Through HTML5 tags, developers can easily add video and audio to web pages. And because the H.264 codec is widely supported, HTML5-based video players currently on the market have been able to solve most compatibility issues.

2. Semantic tags: HTML5 introduces new semantic tags, including

,

,

,

,

,

3. Offline access: HTML5 makes offline application development easier to operate. By using application caching, web applications can run offline and the cached content will be updated the next time they are connected to the Internet.

4. Graphics access: HTML5 graphics APIs, such as Canvas and SVG, allow developers to easily create various vector and raster graphics using standard web technologies such as HTML, CSS, and JavaScript.

5. Preloading: HTML5's attribute allows developers to preload resources into memory before users need them, thereby improving page loading speed.

2. The main features of HTML5

1. Semantic tags

HTML5 adds many new tags, most of which have semantic meaning Label. Web pages that use a large number of semantic tags can allow search engines to better understand the meaning of each tag when reading the web page, and are also helpful for the staged presentation of web pages.

2. Embed multimedia content

HTML5 has made many improvements in the use of multimedia, allowing you to embed video, audio and other multimedia content into web pages without the need for third-party plug-ins, such as < video> and

3. Improved form controls

HTML5 introduces many new form controls, such as date pickers, phone numbers, email addresses and other input boxes. In addition, HTML5 also supports custom form controls through JavaScript and jQuery.

4. Geolocation (Geolocation)

HTML5 supports obtaining the user's location information through the JavaScript geolocation API. Using this interface is very convenient in building location-based Web applications.

5. Local Storage

HTML5 allows the use of local storage to store some temporary data of the website, so that the user's data can be maintained without the need for server operation. HTML5 includes some APIs that allow you to store, read, delete, and query data, such as localStorage and sessionStorage.

3. New technologies of HTML5

Some new technologies have been introduced in HTML5. Here is a brief introduction:

1. WebSocket (Web Socket)

WebSocket is a network technology used for two-way communication between a web browser and a web server. In traditional HTML, a web browser can only send requests to a web server and receive responses. Using WebSocket can achieve two-way communication, that is, the web browser can send requests to the web server and receive responses, and the server can also actively push data to the web browser.

2. Web Workers

Web Workers are suitable for tasks that require heavy computation or have long running times. Web Workers provide a way to perform calculations in a background thread, which avoids locking the browser's UI in the same thread, thereby improving the performance and responsiveness of the entire website.

3. Canvas

Canvas is a new drawing API added in HTML5. By using it in conjunction with JavaScript, you can create very cool effects on web pages. Canvas is often used to create image editors, game special effects and animations, etc.

4. Offline Application Cache

HTML5 supports offline caching. This technology can make the website accessible even when there is no network condition, which is the so-called offline storage. This technology is based on the implementation of a part of the browser's local cache, which caches recently visited web pages on the user's computer, allowing normal browsing even when offline.

4. Simple usage of HTML5

The tags or features in HTML5 will also be used in actual development. The following is the simple usage of these tags or features:

1. Audio and video

<head>
    <title>HTML5音频和视频标签</title>
</head>
<body>
    <video width="320" height="240" controls>
        <source src="movie.mp4" type="video/mp4">
        <source src="movie.ogg" type="video/ogg">
        您的浏览器不支持 HTML5 video 标签。
    </video> 
    <audio controls>
        <source src="song.mp3" type="audio/mpeg">
        <source src="song.ogg" type="audio/ogg">
        您的浏览器不支持 HTML5 audio 标签。
    </audio>
</body>

2.Canvas

<head>
    <title>制作简单的Canvas图形</title>
    <script type="text/javascript">
        function draw(){
            var canvas = document.getElementById("myCanvas");
            if(canvas.getContext){
                var ctx = canvas.getContext("2d");
                ctx.fillStyle = "rgb(200,0,0)";
                ctx.fillRect (10, 10, 55, 50);
                ctx.fillStyle = "rgba(0, 0, 200, 0.5)";
                ctx.fillRect (30, 30, 55, 50);
            }
        }
    </script>
</head>
<body onload="draw()">
    <canvas id="myCanvas" width="150" height="150"></canvas>
</body>

3.WebSockets

var socket = new WebSocket('wss://example.com/socketserver');
//Triggered after the connection is established, you can send data to the server
socket.addEventListener('open ', function (event) {

socket.send('Hello WebSocket!');

});
//Receive the message returned by the server
socket.addEventListener('message', function (event) {

console.log('Message from server', event.data);

});
//Triggered after the connection is closed
socket.addEventListener('close', function (event) {

console.log('WebSocket已关闭');

});

In general, Compared with previous HTML languages, HTML5 adds many new features. These features can help us better carry out web development, and are also more convenient and efficient. HTML5 technology can be applied in many fields, including website construction, web applications, video and audio processing, etc. I believe that HTML5 will become more and more popular in the future. It is very important to learn and master HTML5 technology now.

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