HTML5 study notes: canvas
1.What is canvas?
Labels that can draw graphics. Generally drawn with javascript.
2.Create a canvas
<span style="color: #008080;">1</span> <span style="color: #0000ff;"><!</span><span style="color: #ff00ff;">DOCTYPE html</span><span style="color: #0000ff;">></span> <span style="color: #008080;">2</span> <span style="color: #0000ff;"><</span><span style="color: #800000;">html</span><span style="color: #0000ff;">></span> <span style="color: #008080;">3</span> <span style="color: #0000ff;"><</span><span style="color: #800000;">head</span><span style="color: #0000ff;">></span> <span style="color: #008080;">4</span> <span style="color: #0000ff;"><</span><span style="color: #800000;">title</span><span style="color: #0000ff;">></</span><span style="color: #800000;">title</span><span style="color: #0000ff;">></span> <span style="color: #008080;">5</span> <span style="color: #0000ff;"></</span><span style="color: #800000;">head</span><span style="color: #0000ff;">></span> <span style="color: #008080;">6</span> <span style="color: #0000ff;"><</span><span style="color: #800000;">body</span><span style="color: #0000ff;">></span> <span style="color: #008080;">7</span> <span style="color: #0000ff;"><</span><span style="color: #800000;">canvas </span><span style="color: #ff0000;">id</span><span style="color: #0000ff;">="mycanvas"</span><span style="color: #ff0000;"> width</span><span style="color: #0000ff;">="100"</span><span style="color: #ff0000;"> height</span><span style="color: #0000ff;">="100"</span><span style="color: #0000ff;">></</span><span style="color: #800000;">canvas</span><span style="color: #0000ff;">> //创建画布用canvas标签</span> <span style="color: #008080;">8</span> <span style="color: #0000ff;"></</span><span style="color: #800000;">body</span><span style="color: #0000ff;">></span> <span style="color: #008080;">9</span> <span style="color: #0000ff;"></</span><span style="color: #800000;">html</span><span style="color: #0000ff;">></span>
Copy after login
3. Draw on the canvas.
<span style="color: #008080;"> 1</span> <span style="color: #0000ff;"><</span><span style="color: #800000;">script </span><span style="color: #ff0000;">type</span><span style="color: #0000ff;">="text/javascript"</span><span style="color: #0000ff;">></span> <span style="color: #008080;"> 2</span> <span style="background-color: #f5f5f5; color: #008000;">//</span><span style="background-color: #f5f5f5; color: #008000;">用javascript来绘制图像</span> <span style="color: #008080;"> 3</span> <span style="background-color: #f5f5f5; color: #008000;">//</span><span style="background-color: #f5f5f5; color: #008000;">获取到canvas元素</span> <span style="color: #008080;"> 4</span> <span style="background-color: #f5f5f5; color: #0000ff;">var</span><span style="background-color: #f5f5f5; color: #000000;"> can</span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #000000;">document.getElementById(</span><span style="background-color: #f5f5f5; color: #000000;">"</span><span style="background-color: #f5f5f5; color: #000000;">mycanvas</span><span style="background-color: #f5f5f5; color: #000000;">"</span><span style="background-color: #f5f5f5; color: #000000;">); </span><span style="color: #008080;"> 5</span> <span style="background-color: #f5f5f5; color: #008000;">//</span><span style="background-color: #f5f5f5; color: #008000;">创建html5的内置对象，拥有多种绘制路径、矩形、圆形、字符以及添加图像的方法。</span> <span style="color: #008080;"> 6</span> <span style="background-color: #f5f5f5; color: #0000ff;">var</span><span style="background-color: #f5f5f5; color: #000000;"> draw</span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #000000;">can.getContext(</span><span style="background-color: #f5f5f5; color: #000000;">"</span><span style="background-color: #f5f5f5; color: #000000;">2d</span><span style="background-color: #f5f5f5; color: #000000;">"</span><span style="background-color: #f5f5f5; color: #000000;">); </span><span style="color: #008080;"> 7</span> <span style="background-color: #f5f5f5; color: #008000;">//</span><span style="background-color: #f5f5f5; color: #008000;">fillStyle();可以是css的颜色，渐变，图案</span> <span style="color: #008080;"> 8</span> <span style="background-color: #f5f5f5; color: #000000;"> draw.fillStyle</span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #000000;">"</span><span style="background-color: #f5f5f5; color: #000000;">red</span><span style="background-color: #f5f5f5; color: #000000;">"</span><span style="background-color: #f5f5f5; color: #000000;">; </span><span style="color: #008080;"> 9</span> <span style="background-color: #f5f5f5; color: #008000;">//</span><span style="background-color: #f5f5f5; color: #008000;">fillRect(x,y,width,height) 定义填充方式</span> <span style="color: #008080;">10</span> <span style="background-color: #f5f5f5; color: #000000;"> draw.fillRect(</span><span style="background-color: #f5f5f5; color: #000000;">0</span><span style="background-color: #f5f5f5; color: #000000;">,</span><span style="background-color: #f5f5f5; color: #000000;">0</span><span style="background-color: #f5f5f5; color: #000000;">,</span><span style="background-color: #f5f5f5; color: #000000;">125</span><span style="background-color: #f5f5f5; color: #000000;">,</span><span style="background-color: #f5f5f5; color: #000000;">12</span><span style="background-color: #f5f5f5; color: #000000;">);</span> <span style="color: #008080;">12</span> <span style="color: #0000ff;"></</span><span style="color: #800000;">script</span><span style="color: #0000ff;">></span>
Copy after login
4.canvas-path
<span style="color: #008080;"> 1</span> <span style="color: #0000ff;">var</span> can=document.getElementById("mycanvas"<span style="color: #000000;">);
</span><span style="color: #008080;"> 2</span> <span style="color: #0000ff;">var</span> draw=can.getContext("2d"<span style="color: #000000;">);
</span><span style="color: #008080;"> 3</span> <span style="color: #008000;">//</span><span style="color: #008000;"> 开始一个路径</span>
<span style="color: #008080;"> 4</span> <span style="color: #000000;"> draw.beginPath();
</span><span style="color: #008080;"> 5</span> <span style="color: #008000;">//</span><span style="color: #008000;"> 设置线的粗细</span>
<span style="color: #008080;"> 6</span> draw.lineWidth="5"<span style="color: #000000;">;
</span><span style="color: #008080;"> 7</span> <span style="color: #008000;">//</span><span style="color: #008000;">设置线的颜色</span>
<span style="color: #008080;"> 8</span> draw.strokeStyle="green"<span style="color: #000000;">;
</span><span style="color: #008080;"> 9</span> <span style="color: #008000;">//</span><span style="color: #008000;"> 线的起点</span>
<span style="color: #008080;">10</span> draw.moveTo(0,75<span style="color: #000000;">);
</span><span style="color: #008080;">11</span> <span style="color: #008000;">//</span><span style="color: #008000;">线的终点 </span>
<span style="color: #008080;">12</span> draw.lineTo(250,75<span style="color: #000000;">);
</span><span style="color: #008080;">13</span> <span style="color: #008000;">//</span><span style="color: #008000;"> 开始绘制路径</span>
<span style="color: #008080;">14</span> <span style="color: #000000;"> draw.stroke();
</span><span style="color: #008080;">15</span> <span style="color: #008000;">//</span><span style="color: #008000;">开始另一个路径</span>
<span style="color: #008080;">16</span> <span style="color: #000000;"> draw.beginPath();
</span><span style="color: #008080;">17</span> <span style="color: #008000;">//</span><span style="color: #008000;"> 设置线的粗细</span>
<span style="color: #008080;">18</span> draw.lineWidth="5"<span style="color: #000000;">;
</span><span style="color: #008080;">19</span> draw.strokeStyle="purple"<span style="color: #000000;">;
</span><span style="color: #008080;">20</span> draw.moveTo(25,05<span style="color: #000000;">);
</span><span style="color: #008080;">21</span> draw.lineTo(35,25<span style="color: #000000;">);
</span><span style="color: #008080;">22</span> draw.stroke();Copy after login
Effect:
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
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
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Assassin's Creed Shadows: Seashell Riddle Solution
3 weeks ago
By DDD
What's New in Windows 11 KB5054979 & How to Fix Update Issues
2 weeks ago
By DDD
Where to find the Crane Control Keycard in Atomfall
3 weeks ago
By DDD
Assassin's Creed Shadows - How To Find The Blacksmith And Unlock Weapon And Armour Customisation
1 months ago
By DDD
Roblox: Dead Rails - How To Complete Every Challenge
3 weeks ago
By DDD
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
CakePHP Tutorial
1390
52
1390
52
Is HTML easy to learn for beginners?
Apr 07, 2025 am 12:11 AM
HTML is suitable for beginners because it is simple and easy to learn and can quickly see results. 1) The learning curve of HTML is smooth and easy to get started. 2) Just master the basic tags to start creating web pages. 3) High flexibility and can be used in combination with CSS and JavaScript. 4) Rich learning resources and modern tools support the learning process.
The Roles of HTML, CSS, and JavaScript: Core Responsibilities
Apr 08, 2025 pm 07:05 PM
HTML defines the web structure, CSS is responsible for style and layout, and JavaScript gives dynamic interaction. The three perform their duties in web development and jointly build a colorful website.
What is an example of a starting tag in HTML?
Apr 06, 2025 am 12:04 AM
AnexampleofastartingtaginHTMLis,whichbeginsaparagraph.StartingtagsareessentialinHTMLastheyinitiateelements,definetheirtypes,andarecrucialforstructuringwebpagesandconstructingtheDOM.
Understanding HTML, CSS, and JavaScript: A Beginner's Guide
Apr 12, 2025 am 12:02 AM
WebdevelopmentreliesonHTML,CSS,andJavaScript:1)HTMLstructurescontent,2)CSSstylesit,and3)JavaScriptaddsinteractivity,formingthebasisofmodernwebexperiences.
Gitee Pages static website deployment failed: How to troubleshoot and resolve single file 404 errors?
Apr 04, 2025 pm 11:54 PM
GiteePages static website deployment failed: 404 error troubleshooting and resolution when using Gitee...
How to implement adaptive layout of Y-axis position in web annotation?
Apr 04, 2025 pm 11:30 PM
The Y-axis position adaptive algorithm for web annotation function This article will explore how to implement annotation functions similar to Word documents, especially how to deal with the interval between annotations...
How to use CSS3 and JavaScript to achieve the effect of scattering and enlarging the surrounding pictures after clicking?
Apr 05, 2025 am 06:15 AM
To achieve the effect of scattering and enlarging the surrounding images after clicking on the image, many web designs need to achieve an interactive effect: click on a certain image to make the surrounding...
Why do you need to call Vue.use(VueRouter) in the index.js file under the router folder?
Apr 05, 2025 pm 01:03 PM
The necessity of registering VueRouter in the index.js file under the router folder When developing Vue applications, you often encounter problems with routing configuration. Special...
