HTML5 界面元素 Canvas 参考手册

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HTML5 界面元素 Canvas 参考手册

来源: 作者: 时间:2016-01-23 10:51
HTML5 界面元素 Canvas 参考手册太阳火神的美丽人生 (http: blog csdn net opengl_es)本文遵循署名-非商业用途-保持一致创作公用协议转载请保留此句:太阳火神的美丽人生 - 本博客专注于 敏捷开

HTML5 界面元素 Canvas 参考手册

太阳火神的美丽人生 (http://blog.csdn.net/opengl_es)

本文遵循“署名-非商业用途-保持一致”创作公用协议

转载请保留此句:太阳火神的美丽人生 - 本博客专注于 敏捷开发及移动和物联设备研究:iOS、Android、Html5、Arduino、pcDuino,否则,出自本博客的文章拒绝转载或再转载,谢谢合作。



HTML5 界面元素 Canvas 参考手册
HTML Canvas Reference



描述
Description


The HTML5 tag is used to draw graphics, on the fly, via scripting (usually JavaScript).

However, the element has no drawing abilities of its own (it is only a container for graphics) - you must use a script to actually draw the graphics.

The getContext() method returns an object that provides methods and properties for drawing on the canvas.

This reference will cover the properties and methods of the getContext("2d") object, which can be used to draw text, lines, boxes, circles, and more - on the canvas.



支持
Browser Support


Internet Explorer 9, Firefox, Opera, Chrome, and Safari support and its properties and methods.

Note: Internet Explorer 8 and earlier versions, do not support the element.



颜色、样式和阴影
Colors, Styles, and Shadows


Property

Description

fillStyle

Sets or returns the color, gradient, or pattern used to fill the drawing

strokeStyle

Sets or returns the color, gradient, or pattern used for strokes

shadowColor

Sets or returns the color to use for shadows

shadowBlur

Sets or returns the blur level for shadows

shadowOffsetX

Sets or returns the horizontal distance of the shadow from the shape

shadowOffsetY

Sets or returns the vertical distance of the shadow from the shape


Method

Description

createLinearGradient()

Creates a linear gradient (to use on canvas content)

createPattern()

Repeats a specified element in the specified direction

createRadialGradient()

Creates a radial/circular gradient (to use on canvas content)

addColorStop()

Specifies the colors and stop positions in a gradient object




线条样式
Line Styles


Property

Description

lineCap

Sets or returns the style of the end caps for a line

lineJoin

Sets or returns the type of corner created, when two lines meet

lineWidth

Sets or returns the current line width

miterLimit

Sets or returns the maximum miter length



矩形
Rectangles


Method

Description

rect()

Creates a rectangle

fillRect()

Draws a "filled" rectangle

strokeRect()

Draws a rectangle (no fill)

clearRect()

Clears the specified pixels within a given rectangle


路径
Paths

Method

Description

fill()

Fills the current drawing (path)

stroke()

Actually draws the path you have defined

beginPath()

Begins a path, or resets the current path

moveTo()

Moves the path to the specified point in the canvas, without creating a line

closePath()

Creates a path from the current point back to the starting point

lineTo()

Adds a new point and creates a line from that point to the last specified point in the canvas

clip()

Clips a region of any shape and size from the original canvas

quadraticCurveTo()

Creates a quadratic Bézier curve

bezierCurveTo()

Creates a cubic Bézier curve

arc()

Creates an arc/curve (used to create circles, or parts of circles)

arcTo()

Creates an arc/curve between two tangents

isPointInPath()

Returns true if the specified point is in the current path, otherwise false




转换
Transformations


Method

Description

scale()

Scales the current drawing bigger or smaller

rotate()

Rotates the current drawing

translate()

Remaps the (0,0) position on the canvas

transform()

Replaces the current transformation matrix for the drawing

setTransform()

Resets the current transform to the identity matrix. Then runs transform()




文本
Text


Property

Description

font

Sets or returns the current font properties for text content

textAlign

Sets or returns the current alignment for text content

textBaseline

Sets or returns the current text baseline used when drawing text


Method

Description

fillText()

Draws "filled" text on the canvas

strokeText()

Draws text on the canvas (no fill)

measureText()

Returns an object that contains the width of the specified text




图像绘制
Image Drawing


Method

Description

drawImage()

Draws an image, canvas, or video onto the canvas




像素操作
Pixel Manipulation

Property

Description

width

Returns the width of an ImageData object

height

Returns the height of an ImageData object

data

Returns an object that contains image data of a specified ImageData object


Method

Description

createImageData()

Creates a new, blank ImageData object

getImageData()

Returns an ImageData object that copies the pixel data for the specified rectangle on a canvas

putImageData()

Puts the image data (from a specified ImageData object) back onto the canvas




混合
Compositing


Property

Description

globalAlpha

Sets or returns the current alpha or transparency value of the drawing

globalCompositeOperation

Sets or returns how a new image are drawn onto an existing image




其它
Other


Method

Description

save()

Saves the state of the current context

restore()

Returns previously saved path state and attributes

createEvent()

getContext()

toDataURL()







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