在此页

• 基本范例
• 参考
• Non-standard APIs
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

CanvasRenderingContext2D interface, part of the 画布 API , provides the 2D rendering context for the drawing surface of a <canvas> element. It is used for drawing shapes, text, images, and other objects.

See the interface's properties and methods in the sidebar and below. The Canvas tutorial has more explanation, examples, and resources, as well.

基本范例

To get a CanvasRenderingContext2D instance, you must first have an HTML <canvas> element to work with:

<canvas id="my-house" width="300" height="300"></canvas>
					

To get the canvas' 2D rendering context, call getContext() 在 <canvas> element, supplying '2d' 作为自变量：

const canvas = document.getElementById('my-house');
const ctx = canvas.getContext('2d');
					

With the context in hand, you can draw anything you like. This code draws a house:

// Set line width
ctx.lineWidth = 10;
// Wall
ctx.strokeRect(75, 140, 150, 110);
// Door
ctx.fillRect(130, 190, 40, 60);
// Roof
ctx.beginPath();
ctx.moveTo(50, 140);
ctx.lineTo(150, 60);
ctx.lineTo(250, 140);
ctx.closePath();
ctx.stroke();
					

The resulting drawing looks like this:

参考

Drawing rectangles

There are three methods that immediately draw rectangles to the canvas.

CanvasRenderingContext2D.clearRect()

Sets all pixels in the rectangle defined by starting point (x, y) and size (width, height) to transparent black, erasing any previously drawn content.

CanvasRenderingContext2D.fillRect()

Draws a filled rectangle at (x, y) position whose size is determined by width and height .

CanvasRenderingContext2D.strokeRect()

Paints a rectangle which has a starting point at (x, y) and has a w width and an h height onto the canvas, using the current stroke style.

绘制文本

The following methods draw text. See also the TextMetrics object for text properties.

CanvasRenderingContext2D.fillText()

Draws (fills) a given text at the given (x, y) position.

CanvasRenderingContext2D.strokeText()

Draws (strokes) a given text at the given (x, y) position.

CanvasRenderingContext2D.measureText()

返回 TextMetrics 对象。

Line styles

The following methods and properties control how lines are drawn.

CanvasRenderingContext2D.lineWidth

Width of lines. Default 1.0 .

CanvasRenderingContext2D.lineCap

Type of endings on the end of lines. Possible values: butt (默认)， round , square .

CanvasRenderingContext2D.lineJoin

Defines the type of corners where two lines meet. Possible values: round , bevel , miter (default).

CanvasRenderingContext2D.miterLimit

Miter limit ratio. Default 10 .

CanvasRenderingContext2D.getLineDash()

Returns the current line dash pattern array containing an even number of non-negative numbers.

CanvasRenderingContext2D.setLineDash()

Sets the current line dash pattern.

CanvasRenderingContext2D.lineDashOffset

Specifies where to start a dash array on a line.

文本样式

The following properties control how text is laid out.

CanvasRenderingContext2D.font

Font setting. Default value 10px sans-serif .

CanvasRenderingContext2D.textAlign

Text alignment setting. Possible values: start (默认)， end , left , right , center .

CanvasRenderingContext2D.textBaseline

Baseline alignment setting. Possible values: top , hanging , middle , alphabetic (默认)， ideographic , bottom .

CanvasRenderingContext2D.direction

Directionality. Possible values: ltr , rtl , 继承 (default).

Fill and stroke styles

Fill styling is used for colors and styles inside shapes and stroke styling is used for the lines around shapes.

CanvasRenderingContext2D.fillStyle

Color or style to use inside shapes. Default #000 (黑色)。

CanvasRenderingContext2D.strokeStyle

Color or style to use for the lines around shapes. Default #000 (黑色)。

Gradients and patterns

CanvasRenderingContext2D.createLinearGradient()

Creates a linear gradient along the line given by the coordinates represented by the parameters.

CanvasRenderingContext2D.createRadialGradient()

Creates a radial gradient given by the coordinates of the two circles represented by the parameters.

CanvasRenderingContext2D.createPattern()

Creates a pattern using the specified image (a CanvasImageSource ). It repeats the source in the directions specified by the repetition argument. This method returns a CanvasPattern .

阴影

CanvasRenderingContext2D.shadowBlur

Specifies the blurring effect. Default: 0

CanvasRenderingContext2D.shadowColor

Color of the shadow. Default: fully-transparent black.

CanvasRenderingContext2D.shadowOffsetX

Horizontal distance the shadow will be offset. Default: 0 .

CanvasRenderingContext2D.shadowOffsetY

Vertical distance the shadow will be offset. Default: 0 .

路径

The following methods can be used to manipulate paths of objects.

CanvasRenderingContext2D.beginPath()

Starts a new path by emptying the list of sub-paths. Call this method when you want to create a new path.

CanvasRenderingContext2D.closePath()

Causes the point of the pen to move back to the start of the current sub-path. It tries to draw a straight line from the current point to the start. If the shape has already been closed or has only one point, this function does nothing.

CanvasRenderingContext2D.moveTo()

Moves the starting point of a new sub-path to the (x, y) coordinates.

CanvasRenderingContext2D.lineTo()

Connects the last point in the current sub-path to the specified (x, y) coordinates with a straight line.

CanvasRenderingContext2D.bezierCurveTo()

Adds a cubic Bézier curve to the current path.

CanvasRenderingContext2D.quadraticCurveTo()

Adds a quadratic Bézier curve to the current path.

CanvasRenderingContext2D.arc()

Adds a circular arc to the current path.

CanvasRenderingContext2D.arcTo()

Adds an arc to the current path with the given control points and radius, connected to the previous point by a straight line.

CanvasRenderingContext2D.ellipse()

Adds an elliptical arc to the current path.

CanvasRenderingContext2D.rect()

Creates a path for a rectangle at position (x, y) with a size that is determined by width and height .

Drawing paths

CanvasRenderingContext2D.fill()

Fills the current sub-paths with the current fill style.

CanvasRenderingContext2D.stroke()

Strokes the current sub-paths with the current stroke style.

CanvasRenderingContext2D.drawFocusIfNeeded()

If a given element is focused, this method draws a focus ring around the current path.

CanvasRenderingContext2D.scrollPathIntoView()

Scrolls the current path or a given path into the view.

CanvasRenderingContext2D.clip()

Creates a clipping path from the current sub-paths. Everything drawn after clip() is called appears inside the clipping path only. For an example, see Clipping paths in the Canvas tutorial.

CanvasRenderingContext2D.isPointInPath()

Reports whether or not the specified point is contained in the current path.

CanvasRenderingContext2D.isPointInStroke()

Reports whether or not the specified point is inside the area contained by the stroking of a path.

变换

Objects in the CanvasRenderingContext2D rendering context have a current transformation matrix and methods to manipulate it. The transformation matrix is applied when creating the current default path, painting text, shapes and Path2D objects. The methods listed below remain for historical and compatibility reasons as SVGMatrix objects are used in most parts of the API nowadays and will be used in the future instead.

CanvasRenderingContext2D.currentTransform

Current transformation matrix ( SVGMatrix 对象)。

CanvasRenderingContext2D.getTransform

Retrieves the current transformation matrix being applied to the context.

CanvasRenderingContext2D.rotate()

Adds a rotation to the transformation matrix. The angle argument represents a clockwise rotation angle and is expressed in radians.

CanvasRenderingContext2D.scale()

Adds a scaling transformation to the canvas units by x horizontally and by y vertically.

CanvasRenderingContext2D.translate()

Adds a translation transformation by moving the canvas and its origin x horzontally and y vertically on the grid.

CanvasRenderingContext2D.transform()

Multiplies the current transformation matrix with the matrix described by its arguments.

CanvasRenderingContext2D.setTransform()

Resets the current transform to the identity matrix, and then invokes the transform() method with the same arguments.

CanvasRenderingContext2D.resetTransform()

Resets the current transform by the identity matrix.

合成

CanvasRenderingContext2D.globalAlpha

Alpha value that is applied to shapes and images before they are composited onto the canvas. Default 1.0 (opaque).

CanvasRenderingContext2D.globalCompositeOperation

采用 globalAlpha applied this sets how shapes and images are drawn onto the existing bitmap.

Drawing images

CanvasRenderingContext2D.drawImage()

Draws the specified image. This method is available in multiple formats, providing a great deal of flexibility in its use.

Pixel manipulation

另请参阅 ImageData 对象。

CanvasRenderingContext2D.createImageData()

Creates a new, blank ImageData object with the specified dimensions. All of the pixels in the new object are transparent black.

CanvasRenderingContext2D.getImageData()

返回 ImageData object representing the underlying pixel data for the area of the canvas denoted by the rectangle which starts at (sx, sy) and has an sw width and sh height.

CanvasRenderingContext2D.putImageData()

Paints data from the given ImageData object onto the bitmap. If a dirty rectangle is provided, only the pixels from that rectangle are painted.

Image smoothing

CanvasRenderingContext2D.imageSmoothingEnabled

Image smoothing mode; if disabled, images will not be smoothed if scaled.

CanvasRenderingContext2D.imageSmoothingQuality

Allows you to set the quality of image smoothing.

The canvas state

CanvasRenderingContext2D rendering context contains a variety of drawing style states (attributes for line styles, fill styles, shadow styles, text styles). The following methods help you to work with that state:

CanvasRenderingContext2D.save()

Saves the current drawing style state using a stack so you can revert any change you make to it using restore() .

CanvasRenderingContext2D.restore()

Restores the drawing style state to the last element on the 'state stack' saved by save() .

CanvasRenderingContext2D.canvas

A read-only back-reference to the HTMLCanvasElement . Might be null if it is not associated with a <canvas> 元素。

Hit regions

CanvasRenderingContext2D.addHitRegion()

Adds a hit region to the canvas.

CanvasRenderingContext2D.removeHitRegion()

Removes the hit region with the specified id from the canvas.

CanvasRenderingContext2D.clearHitRegions()

Removes all hit regions from the canvas.

过滤器

CanvasRenderingContext2D.filter

Applies a CSS or SVG filter to the canvas, e.g., to change its brightness or bluriness.

Non-standard APIs

Blink and WebKit

Most of these APIs are deprecated and were removed shortly after Chrome 36 .

CanvasRenderingContext2D.clearShadow()

Removes all shadow settings like CanvasRenderingContext2D.shadowColor and CanvasRenderingContext2D.shadowBlur .

CanvasRenderingContext2D.drawImageFromRect()

This is redundant with an equivalent overload of drawImage .

CanvasRenderingContext2D.setAlpha()

使用 CanvasRenderingContext2D.globalAlpha 代替。

CanvasRenderingContext2D.setCompositeOperation()

使用 CanvasRenderingContext2D.globalCompositeOperation 代替。

CanvasRenderingContext2D.setLineWidth()

使用 CanvasRenderingContext2D.lineWidth 代替。

CanvasRenderingContext2D.setLineJoin()

使用 CanvasRenderingContext2D.lineJoin 代替。

CanvasRenderingContext2D.setLineCap()

使用 CanvasRenderingContext2D.lineCap 代替。

CanvasRenderingContext2D.setMiterLimit()

使用 CanvasRenderingContext2D.miterLimit 代替。

CanvasRenderingContext2D.setStrokeColor()

使用 CanvasRenderingContext2D.strokeStyle 代替。

CanvasRenderingContext2D.setFillColor()

使用 CanvasRenderingContext2D.fillStyle 代替。

CanvasRenderingContext2D.setShadow()

使用 CanvasRenderingContext2D.shadowColor and CanvasRenderingContext2D.shadowBlur 代替。

CanvasRenderingContext2D.webkitLineDash

使用 CanvasRenderingContext2D.getLineDash() and CanvasRenderingContext2D.setLineDash() 代替。

CanvasRenderingContext2D.webkitLineDashOffset

使用 CanvasRenderingContext2D.lineDashOffset 代替。

CanvasRenderingContext2D.webkitImageSmoothingEnabled

使用 CanvasRenderingContext2D.imageSmoothingEnabled 代替。

Blink only

CanvasRenderingContext2D.isContextLost()

Inspired by the same WebGLRenderingContext method it returns true if the Canvas context has been lost, or false 若不。

WebKit only

CanvasRenderingContext2D.webkitBackingStorePixelRatio

The backing store size in relation to the canvas element. See High DPI Canvas .

CanvasRenderingContext2D.webkitGetImageDataHD

Intended for HD backing stores, but removed from canvas specifications.

CanvasRenderingContext2D.webkitPutImageDataHD

Intended for HD backing stores, but removed from canvas specifications.

Gecko only

Prefixed APIs

CanvasRenderingContext2D.mozCurrentTransform

Sets or gets the current transformation matrix, see CanvasRenderingContext2D.currentTransform .

CanvasRenderingContext2D.mozCurrentTransformInverse

Sets or gets the current inversed transformation matrix.

CanvasRenderingContext2D.mozImageSmoothingEnabled

见 CanvasRenderingContext2D.imageSmoothingEnabled .

CanvasRenderingContext2D.mozTextStyle

Introduced in in Gecko 1.9, deprecated in favor of the CanvasRenderingContext2D.font 特性。

CanvasRenderingContext2D.mozDrawText()

This method was introduced in Gecko 1.9 and is removed starting with Gecko 7.0. Use CanvasRenderingContext2D.strokeText() or CanvasRenderingContext2D.fillText() 代替。

CanvasRenderingContext2D.mozMeasureText()

This method was introduced in Gecko 1.9 and is unimplemented starting with Gecko 7.0. Use CanvasRenderingContext2D.measureText() 代替。

CanvasRenderingContext2D.mozPathText()

This method was introduced in Gecko 1.9 and is removed starting with Gecko 7.0.

CanvasRenderingContext2D.mozTextAlongPath()

This method was introduced in Gecko 1.9 and is removed starting with Gecko 7.0.

Internal APIs (chrome-context only)

CanvasRenderingContext2D.drawWindow()

Renders a region of a window into the canvas . The contents of the window's viewport are rendered, ignoring viewport clipping and scrolling.

CanvasRenderingContext2D.demote()

This causes a context that is currently using a hardware-accelerated backend to fallback to a software one. All state should be preserved.

Internet Explorer

CanvasRenderingContext2D.msFillRule

fill rule to use. This must be one of evenodd or nonzero (default).

规范

规范	状态	注释
HTML 实时标准 The definition of 'CanvasRenderingContext2D' in that specification.	实时标准

浏览器兼容性

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据

	桌面						移动
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
CanvasRenderingContext2D	Chrome 1	Edge 12	Firefox 1.5	IE 9	Opera 9	Safari 2	WebView Android 1	Chrome Android 18	Firefox Android 4	Opera Android 10.1	Safari iOS 1	Samsung Internet Android 1.0
addHitRegion	Chrome Yes Disabled Yes Disabled Disabled This feature is behind the Experimental Web Platform Features preference. To change preferences in Chrome, visit chrome://flags.	Edge ≤79 Disabled ≤79 Disabled Disabled From version ≤79: this feature is behind the Experimental Web Platform Features preference.	Firefox 30 Disabled 30 Disabled Disabled From version 30: this feature is behind the canvas.hitregions.enabled preference. To change preferences in Firefox, visit about:config.	IE 不支持 No	Opera 不支持 No	Safari 不支持 No	WebView Android 不支持 No	Chrome Android 不支持 No	Firefox Android 30 Disabled 30 Disabled Disabled From version 30: this feature is behind the canvas.hitregions.enabled preference. To change preferences in Firefox, visit about:config.	Opera Android 不支持 No	Safari iOS 不支持 No	Samsung Internet Android 不支持 No
arc	Chrome 1	Edge 12	Firefox 1.5	IE 9	Opera 11.6	Safari 3	WebView Android 1	Chrome Android 18	Firefox Android 4	Opera Android 12	Safari iOS 1	Samsung Internet Android 1.0
arcTo	Chrome 1	Edge 12	Firefox 1.5	IE 9	Opera 11.6	Safari 2	WebView Android 1	Chrome Android 18	Firefox Android 4	Opera Android 12	Safari iOS 1	Samsung Internet Android 1.0
beginPath	Chrome Yes	Edge 12	Firefox 1.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
bezierCurveTo	Chrome 1	Edge 12	Firefox 1.5	IE 9	Opera 11.6	Safari 2	WebView Android 1	Chrome Android 18	Firefox Android 4	Opera Android 12	Safari iOS 1	Samsung Internet Android 1.0
canvas	Chrome Yes	Edge 12	Firefox 1.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
clearHitRegions 弃用 非标	Chrome Yes Disabled Yes Disabled Disabled This feature is behind the Experimental Web Platform Features preference. To change preferences in Chrome, visit chrome://flags.	Edge ≤79 Disabled ≤79 Disabled Disabled From version ≤79: this feature is behind the Experimental Web Platform Features preference.	Firefox 38 Disabled 38 Disabled Disabled From version 38: this feature is behind the canvas.hitregions.enabled preference. To change preferences in Firefox, visit about:config.	IE 不支持 No	Opera 不支持 No	Safari 不支持 No	WebView Android 不支持 No	Chrome Android 不支持 No	Firefox Android 38 Disabled 38 Disabled Disabled From version 38: this feature is behind the canvas.hitregions.enabled preference. To change preferences in Firefox, visit about:config.	Opera Android 不支持 No	Safari iOS 不支持 No	Samsung Internet Android 不支持 No
clearRect	Chrome Yes	Edge 12	Firefox 1.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
clip	Chrome Yes	Edge 12	Firefox 1.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
closePath	Chrome 1	Edge 12	Firefox 1.5	IE 9	Opera 11.6	Safari 2	WebView Android 1	Chrome Android 18	Firefox Android 4	Opera Android 12	Safari iOS 1	Samsung Internet Android 1.0
createImageData	Chrome Yes	Edge 12	Firefox 2	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
createLinearGradient	Chrome Yes	Edge 12	Firefox 1.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
createPattern	Chrome Yes	Edge 12	Firefox 1.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
createRadialGradient	Chrome Yes	Edge 12	Firefox 1.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
currentTransform	Chrome Yes Disabled Yes Disabled Disabled This feature is behind the Experimental Web Platform Features preference. To change preferences in Chrome, visit chrome://flags.	Edge ≤18	Firefox 不支持 No 注意事项 No 注意事项 见 bug 928150 . Firefox also supports the experimental and prefixed properties mozCurrentTransform and mozCurrentTransformInverse which set or get the current (inverse) transformation matrix.	IE 不支持 No	Opera 不支持 No	Safari 不支持 No 注意事项 No 注意事项 见 webkitbug(174278) .	WebView Android 不支持 No	Chrome Android 不支持 No	Firefox Android 不支持 No	Opera Android 不支持 No	Safari iOS 不支持 No	Samsung Internet Android 不支持 No
direction	Chrome Yes Disabled Yes Disabled Disabled This feature is behind the Experimental Web Platform Features preference. To change preferences in Chrome, visit chrome://flags.	Edge ≤79 Disabled ≤79 Disabled Disabled From version ≤79: this feature is behind the Experimental Web Platform Features preference.	Firefox 不支持 No	IE 不支持 No	Opera 不支持 No	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 不支持 No	Opera Android 不支持 No	Safari iOS Yes	Samsung Internet Android Yes
drawFocusIfNeeded	Chrome Yes	Edge 14	Firefox 32 32 29 Disabled Disabled From version 29: this feature is behind the canvas.focusring.enabled preference. To change preferences in Firefox, visit about:config. 28 Alternate Name Alternate Name Uses the non-standard name: drawSystemFocusRing	IE 不支持 No	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 32 32 29 Disabled Disabled From version 29: this feature is behind the canvas.focusring.enabled preference. To change preferences in Firefox, visit about:config. 28 Alternate Name Alternate Name Uses the non-standard name: drawSystemFocusRing	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
drawImage	Chrome 1	Edge 12	Firefox 1.5	IE 9	Opera 9	Safari 2	WebView Android 1	Chrome Android 18	Firefox Android 4	Opera Android 10.1	Safari iOS 1	Samsung Internet Android 1.0
drawWidgetAsOnScreen 非标	Chrome 不支持 No	Edge 不支持 No	Firefox 41	IE 不支持 No	Opera 不支持 No	Safari 不支持 No	WebView Android 不支持 No	Chrome Android 不支持 No	Firefox Android 41	Opera Android 不支持 No	Safari iOS 不支持 No	Samsung Internet Android 不支持 No
drawWindow 非标	Chrome 不支持 No	Edge 不支持 No	Firefox 1.5	IE 不支持 No	Opera 不支持 No	Safari 不支持 No	WebView Android 不支持 No	Chrome Android 不支持 No	Firefox Android 4	Opera Android 不支持 No	Safari iOS 不支持 No	Samsung Internet Android 不支持 No
ellipse	Chrome 31	Edge 13	Firefox 48	IE 不支持 No	Opera 18	Safari 9	WebView Android 4.4.3	Chrome Android 31	Firefox Android 48	Opera Android 18	Safari iOS 9	Samsung Internet Android 2.0
fill	Chrome Yes	Edge 12	Firefox 1.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
fillRect	Chrome 1	Edge 12	Firefox 1.5	IE 9	Opera 9	Safari 2	WebView Android 1	Chrome Android 18	Firefox Android 4	Opera Android 10.1	Safari iOS 1	Samsung Internet Android 1.0
fillStyle	Chrome Yes	Edge 12	Firefox 1.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
fillText	Chrome Yes	Edge 12	Firefox 3.5	IE 9	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
filter	Chrome 52	Edge 79	Firefox 49	IE 不支持 No	Opera 不支持 No	Safari 不支持 No	WebView Android 52	Chrome Android 52	Firefox Android 49	Opera Android 不支持 No	Safari iOS 不支持 No	Samsung Internet Android 6.0
font	Chrome Yes	Edge 12	Firefox 3.5	IE 9	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
getImageData	Chrome 1	Edge 12	Firefox 2 注意事项 2 注意事项 Since Firefox 5, getImageData now correctly accepts rectangles that extend beyond the bounds of the canvas; pixels outside the canvas are returned as transparent black and now also returns at least one pixel's worth of image data if a rectangle smaller than one pixel is specified.	IE 9	Opera 9.5	Safari 4	WebView Android 1	Chrome Android 18	Firefox Android 4 注意事项 4 注意事项 Since Firefox 5, getImageData now correctly accepts rectangles that extend beyond the bounds of the canvas; pixels outside the canvas are returned as transparent black and now also returns at least one pixel's worth of image data if a rectangle smaller than one pixel is specified.	Opera Android 10.1	Safari iOS 3.2	Samsung Internet Android 1.0
getLineDash	Chrome Yes	Edge 12	Firefox 27	IE 11	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 27	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
getTransform	Chrome 68	Edge 79	Firefox 70	IE 不支持 No	Opera 55	Safari 11	WebView Android 68	Chrome Android 68	Firefox Android 不支持 No	Opera Android 48	Safari iOS 11	Samsung Internet Android 10.0
globalAlpha	Chrome Yes	Edge 12	Firefox 1.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
globalCompositeOperation	Chrome 1	Edge 12	Firefox 1.5	IE 9	Opera 9	Safari 2	WebView Android 1	Chrome Android 18	Firefox Android 4	Opera Android 10.1	Safari iOS 1	Samsung Internet Android 1.0
imageSmoothingEnabled	Chrome 30 30 ? — 30 Prefixed Prefixed Implemented with the vendor prefix: webkit	Edge 15	Firefox 51 51 ? — 51 Prefixed Prefixed Implemented with the vendor prefix: moz	IE Yes Prefixed Yes Prefixed Prefixed Implemented with the vendor prefix: ms	Opera Yes	Safari Yes	WebView Android 4.4	Chrome Android Yes	Firefox Android 51 51 ? — 51 Prefixed Prefixed Implemented with the vendor prefix: moz	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
imageSmoothingQuality	Chrome 54	Edge ≤79	Firefox 不支持 No	IE ?	Opera 41	Safari Yes	WebView Android 54	Chrome Android 54	Firefox Android 不支持 No	Opera Android 41	Safari iOS Yes	Samsung Internet Android 6.0
isPointInPath	Chrome Yes	Edge 12	Firefox 2	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
isPointInStroke	Chrome Yes	Edge 79	Firefox 20 20 19 — 20 Prefixed Prefixed Implemented with the vendor prefix: moz	IE 不支持 No	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 20 20 19 — 20 Prefixed Prefixed Implemented with the vendor prefix: moz	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
lineCap	Chrome Yes	Edge 12	Firefox 1.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
lineDashOffset	Chrome Yes	Edge 12	Firefox 27 27 7 Alternate Name Alternate Name Uses the non-standard name: mozDashOffset	IE 11	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 27 27 7 Alternate Name Alternate Name Uses the non-standard name: mozDashOffset	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
lineJoin	Chrome Yes	Edge 12	Firefox 1.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
lineTo	Chrome 1	Edge 12	Firefox 1.5	IE 9	Opera 11.6	Safari 2	WebView Android 1	Chrome Android 18	Firefox Android 4	Opera Android 12	Safari iOS 1	Samsung Internet Android 1.0
lineWidth	Chrome Yes	Edge 12	Firefox 1.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
measureText	Chrome Yes	Edge 12	Firefox 2	IE 9	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
miterLimit	Chrome Yes	Edge 12	Firefox 1.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
moveTo	Chrome 1	Edge 12	Firefox 1.5	IE 9	Opera 11.6	Safari 2	WebView Android 1	Chrome Android 18	Firefox Android 4	Opera Android 12	Safari iOS 1	Samsung Internet Android 1.0
putImageData	Chrome Yes	Edge 12	Firefox 2	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
quadraticCurveTo	Chrome 1	Edge 12	Firefox 1.5	IE 9	Opera 11.6	Safari 3	WebView Android 1	Chrome Android 18	Firefox Android 4	Opera Android 12	Safari iOS 1	Samsung Internet Android 1.0
rect	Chrome 1	Edge 12	Firefox 1.5	IE 9	Opera 11.6	Safari 2	WebView Android 1	Chrome Android 18	Firefox Android 4	Opera Android 12	Safari iOS 1	Samsung Internet Android 1.0
removeHitRegion 弃用 非标	Chrome Yes Disabled Yes Disabled Disabled This feature is behind the Experimental Web Platform Features preference. To change preferences in Chrome, visit chrome://flags.	Edge 79 Disabled 79 Disabled Disabled From version 79: this feature is behind the Experimental Web Platform Features preference. 12 — 79	Firefox 30 Disabled 30 Disabled Disabled From version 30: this feature is behind the canvas.hitregions.enabled preference. To change preferences in Firefox, visit about:config.	IE Yes	Opera Yes	Safari Yes	WebView Android 不支持 No	Chrome Android 不支持 No	Firefox Android 30 Disabled 30 Disabled Disabled From version 30: this feature is behind the canvas.hitregions.enabled preference. To change preferences in Firefox, visit about:config.	Opera Android Yes	Safari iOS Yes	Samsung Internet Android 不支持 No
resetTransform	Chrome 31	Edge 79	Firefox 36	IE 不支持 No	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 36	Opera Android 不支持 No	Safari iOS Yes	Samsung Internet Android Yes
restore	Chrome Yes	Edge 12	Firefox 1.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
rotate	Chrome Yes	Edge 12	Firefox 1.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
save	Chrome Yes	Edge 12	Firefox 1.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
scale	Chrome Yes	Edge 12	Firefox 1.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
scrollPathIntoView	Chrome Yes Disabled Yes Disabled Disabled This feature is behind the Experimental Web Platform Features preference. To change preferences in Chrome, visit chrome://flags.	Edge ≤79 Disabled ≤79 Disabled Disabled From version ≤79: this feature is behind the Experimental Web Platform Features preference.	Firefox 不支持 No	IE 不支持 No	Opera Yes	Safari 不支持 No	WebView Android Yes	Chrome Android Yes	Firefox Android 不支持 No	Opera Android 不支持 No	Safari iOS 不支持 No	Samsung Internet Android Yes
setLineDash	Chrome 23	Edge 12	Firefox 27	IE 11	Opera 15	Safari 6.1	WebView Android ≤37	Chrome Android 25	Firefox Android 27	Opera Android 14	Safari iOS 7	Samsung Internet Android 1.5
setTransform	Chrome Yes	Edge 12	Firefox 3	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
shadowBlur	Chrome Yes	Edge 12	Firefox 1.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
shadowColor	Chrome Yes	Edge 12	Firefox 1.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
shadowOffsetX	Chrome Yes	Edge 12	Firefox 1.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
shadowOffsetY	Chrome Yes	Edge 12	Firefox 1.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
stroke	Chrome Yes	Edge 12	Firefox 1.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
strokeRect	Chrome Yes	Edge 12	Firefox 1.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
strokeStyle	Chrome Yes	Edge 12	Firefox 1.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
strokeText	Chrome Yes	Edge 12	Firefox 3.5	IE 9	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android Yes	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
textAlign	Chrome Yes	Edge 12	Firefox 3.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
textBaseline	Chrome Yes	Edge 12	Firefox 3.5	IE 9	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
transform	Chrome Yes	Edge 12	Firefox 3	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes
translate	Chrome Yes	Edge 12	Firefox 1.5	IE Yes	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes

图例

完整支持

完整支持

不支持

不支持

兼容性未知 ?

兼容性未知

实验。期望将来行为有所改变。

实验。期望将来行为有所改变。

非标。预期跨浏览器支持较差。

弃用。不要用于新网站。

弃用。不要用于新网站。

见实现注意事项。

用户必须明确启用此特征。

用户必须明确启用此特征。

使用非标名称。

使用非标名称。

要求使用供应商前缀或不同名称。

要求使用供应商前缀或不同名称。

另请参阅

• HTMLCanvasElement
• <canvas>

元数据

• 最后修改： 2020 年 3 月 9 日

相关话题

1. CanvasRenderingContext2D
2. 特性

   1. canvas
   2. currentTransform
   3. direction
   4. fillStyle
   5. filter
   6. font
   7. globalAlpha
   8. globalCompositeOperation
   9. imageSmoothingEnabled
   10. imageSmoothingQuality
   11. lineCap
   12. lineDashOffset
   13. lineJoin
   14. lineWidth
   15. miterLimit
   16. shadowBlur
   17. shadowColor
   18. shadowOffsetX
   19. shadowOffsetY
   20. strokeStyle
   21. textAlign
   22. textBaseline
3. 方法

   1. addHitRegion()
   2. arc()
   3. arcTo()
   4. beginPath()
   5. bezierCurveTo()
   6. clearHitRegions()
   7. clearRect()
   8. clip()
   9. closePath()
   10. createImageData()
   11. createLinearGradient()
   12. createPattern()
   13. createRadialGradient()
   14. drawFocusIfNeeded()
   15. drawImage()
   16. drawWidgetAsOnScreen()
   17. drawWindow()
   18. ellipse()
   19. fill()
   20. fillRect()
   21. fillText()
   22. getImageData()
   23. getLineDash()
   24. getTransform()
   25. isPointInPath()
   26. isPointInStroke()
   27. lineTo()
   28. measureText()
   29. moveTo()
   30. putImageData()
   31. quadraticCurveTo()
   32. rect()
   33. removeHitRegion()
   34. resetTransform()
   35. restore()
   36. rotate()
   37. save()
   38. scale()
   39. scrollPathIntoView()
   40. setLineDash()
   41. setTransform()
   42. stroke()
   43. strokeRect()
   44. strokeText()
   45. transform()
   46. translate()