在此页

• 句法
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

CanvasRenderingContext2D .globalCompositeOperation property of the Canvas 2D API sets the type of compositing operation to apply when drawing new shapes.

另请参阅 Compositing and clipping 在 Canvas Tutorial .

句法

ctx.globalCompositeOperation = type;
					

type 是 字符串 identifying which of the compositing or blending mode operations to use.

类型

范例

Changing the composite operation

此范例使用 globalCompositeOperation property to draw two rectangles that exclude themselves where they overlap.

HTML

<canvas id="canvas"></canvas>
					

JavaScript

const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');
ctx.globalCompositeOperation = 'xor';
ctx.fillStyle = 'blue';
ctx.fillRect(10, 10, 100, 100);
ctx.fillStyle = 'red';
ctx.fillRect(50, 50, 100, 100);
					

结果

规范

规范	状态	注释
HTML 实时标准 The definition of 'CanvasRenderingContext2D.globalCompositeOperation' in that specification.	实时标准
Compositing and Blending Level 1	候选推荐

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
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

图例

完整支持

完整支持

WebKit/Blink-specific notes

• In WebKit- and Blink-based Browsers, a non-standard and deprecated method ctx.setCompositeOperation() is implemented besides this property.
• 支持 "plus-darker" and "darker" were removed in Chrome 48. Developers looking for a replacement should use "darken" .

Gecko-specific notes

• An early Canvas specification draft specified the value "darker" . However, Firefox removed support for "darker" in version 4 ( bug 571532 )。另请参阅 this blog post that suggests using "difference" as a way to achieve a similar affect to "darker" .

另请参阅

• The interface defining this property: CanvasRenderingContext2D
• CanvasRenderingContext2D.globalAlpha

元数据

• 最后修改： Sep 5, 2019

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()