Community Learn Tools Library Leisure
search
English
Home > Web Front-end > H5 Tutorial > How to draw lines with canvas

How to draw lines with canvas

php中世界最好的语言
Release： 2018-03-14 09:45:17
Original
2362 people have browsed it

This time I will show you how to use canvas to draw lines, and what are the precautions for using canvas to draw lines. The following is a practical case, let's take a look.

Canvas is a new tag in html5. The tag is just a graphics container, and you must use a script to draw graphics.

Next, we use canvas to draw lines.
First, create a new html file and add the canvas tag to the file, as shown below. 

<!DOCTYPE html><html lang="en"><head>
    <meta charset="UTF-8"/>
    <title>Canvas绘图与动画基础</title></head><body><style>
    #canvas{        border: 1px solid #aaa;        text-align: center;
    }</style><canvas id="canvas" width="1024" height="768">
    当用户浏览器不支持Canvas,请更换浏览器重试！</canvas></body></html>
Copy after login

If the browser does not support the canvas tag, the fonts in the canvas tag will be displayed. Under normal circumstances, the paintings in the canvas will be displayed.

Now, let's start drawing a line.
First, get the canvas: 

var canvas = document.getElementById("canvas");
Copy after login

The width and height of the canvas are generally not set in style. They can be set in the same level of canvas and id, as shown in the html above, or set using js. . 


canvas.width=1014;
 canvas.height=768;
Copy after login

Come down and get the context of drawing


var context = canvas.getContext("2d");
Copy after login

We generally use context to operate canvas. Come on, let’s learn more about it in the code: 

        var context = canvas.getContext("2d");//得到绘图的上下文环境
        context.beginPath();//开始绘制线条，若不使用beginPath，则不能绘制多条线条
        context.moveTo(100, 100);//线条开始位置
        context.lineTo(700, 700);//线条经过点
        context.lineTo(100, 700);
        context.lineTo(100, 100);
        context.closePath();//结束绘制线条，不是必须的
       
        context.lineWidth = 5;//设置线条宽度
        context.strokeStyle = "red";//设置线条颜色
        context.stroke();//用于绘制线条
        context.beginPath();
        context.moveTo(200, 100);
        context.lineTo(700, 600);
        context.closePath();
        context.strokeStyle = "black";
        context.stroke();
Copy after login

Run the above code and get a red closed triangle and a black solid line, as shown below:

How to draw lines with canvas

I believe you have seen it You have mastered the method in the case of this article. For more exciting information, please pay attention to php Chinese website

Other related articles!

Recommended reading:

How to use canvas to draw a colorful tangram

What does class="no-js" mean?

The above is the detailed content of How to draw lines with canvas. For more information, please follow other related articles on the PHP Chinese website!

Related labels：
canvas line draw
source：php.cn
Previous article：How to use canvas to draw a colorful tangram Next article：How to draw arcs and circles with canvas
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
Latest Articles by Author
Latest Issues
Can PDF files run HTML5 and Javascript? I have a stupid idea to try and make a program that won't be blocked on any computer since...
From 2024-04-05 12:57:00
0
1
456
Get the *two* height values ​​of the canvas? I'm trying to get two height values ​​of this canvas. <canvaswidth="886"heigh...
From 2024-04-05 09:32:33
0
1
1360
How to export jpg from multiple canvases I have multiple canvases which are used as layers. canvasc1=backgroundimage.canvasc2=chara...
From 2024-04-03 21:02:43
0
1
319
Why does every time I save my Vite React project, a new canvas element is added to the page body instead of replacing the existing canvas element? I'm trying to start learning ThreeJs (I'm also new to Javascript web development). After w...
From 2024-03-30 09:57:49
0
1
396
Related Topics
More>
Popular Recommendations
Popular Tutorials
More>
Related Tutorials
Popular Recommendations
Latest courses
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template