Canvas attributes include width, height, getContext(), style, toDataURL(), toBlob(), getContextAttributes(), clientWidth, clientHeight, offsetWidth, offsetHeight attributes, etc. Detailed introduction: 1. Width attribute, set the width of the Canvas element, the default value is 300 pixels; 2. Height attribute, etc.
The operating environment of this tutorial: Windows 10 system, Dell G3 computer.
Canvas is an element in HTML5 used to draw graphics, animations and other visual effects on web pages. It provides an area for drawing via JavaScript and can be used to create charts, games, image editors, and more.
The Canvas element itself does not have many properties, but it has some important properties that can be used to control the behavior and style of drawing. The following are some commonly used Canvas properties:
1. width: Set or return the width of the Canvas element. The default value is 300 pixels.
2. height: Set or return the height of the Canvas element. The default value is 150 pixels.
3. getContext(): Returns a drawing context object for drawing graphics on Canvas. Commonly used context objects are "2d" and "webgl".
4. style: Set or return the style attributes of the Canvas element, such as background color, border, etc.
5. toDataURL(): Convert the image on the Canvas to a data URL, which can be used to save the image or display it elsewhere.
6. toBlob(): Converts the image on Canvas to a Blob object, which can be used to save the image or upload to the server.
7. getContextAttributes(): Returns an object containing the attributes and values of the current drawing context.
8. clientWidth: Returns the visible width of the Canvas element, excluding borders and scroll bars.
9. clientHeight: Returns the visible height of the Canvas element, excluding borders and scroll bars.
10. offsetWidth: Returns the overall width of the Canvas element, including borders and scroll bars.
11. offsetHeight: Returns the overall height of the Canvas element, including borders and scroll bars.
These properties can be obtained and set through JavaScript to control and operate Canvas. For example, you can change the size of the Canvas by setting the width and height properties, obtain the drawing context object through the getContext() method, and then use the methods and properties of the context object to draw graphics.
To summarize, the properties of the Canvas element are mainly used to control the size, style and drawing context acquisition of the Canvas. Through these properties, we can achieve a variety of drawing effects and interactive functions.
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