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HTML Canvas 教程


Your browser does not support the <canvas> element.

The HTML <canvas> element is used to draw graphics on a web page.

The graphic above is created with <canvas>.

It shows four elements: a red rectangle, a gradient rectangle, a multicolor rectangle, and a multicolor text.


什么是 HTML Canvas?

The HTML <canvas> element is used to draw graphics, on the fly, via scripting (usually JavaScript).

The <canvas> element is only a container for graphics. You must use a script to actually draw the graphics.

Canvas has several methods for drawing paths, boxes, circles, text, and adding images.


浏览器支持

The numbers in the table specify the first browser version that fully supports the <canvas> element.

元素
<canvas> 4.0 9.0 2.0 3.1 9.0

HTML Canvas Can Draw Text

Canvas can draw colorful text, with or without animation.


HTML Canvas Can Draw Graphics

Canvas has great features for graphical data presentation with an imagery of graphs and charts.



HTML Canvas Can be Animated

Canvas objects can move. Everything is possible: from simple bouncing balls to complex animations.


HTML Canvas Can be Interactive

Canvas can respond to JavaScript events.

Canvas can respond to any user action (key clicks, mouse clicks, button clicks, finger movement).


HTML Canvas Can be Used in Games

Canvas' methods for animations, offer a lot of possibilities for HTML gaming applications.


Canvas 实例

In HTML, a <canvas> element looks like this:

<canvas id="myCanvas" width="200" height="100"></canvas>

The <canvas> element must have an id attribute so it can be referred to by JavaScript.

The width and height attribute is necessary to define the size of the canvas.

提示: You can have multiple <canvas> elements on one HTML page.

By default, the <canvas> element has no border and no content.

To add a border, use a style attribute:

实例

<canvas id="myCanvas" width="200" height="100" style="border:1px solid #000000;"></canvas>
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The next chapters show how to draw on the canvas.