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• 句法
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

CanvasRenderingContext2D .beginPath() method of the Canvas 2D API starts a new path by emptying the list of sub-paths. Call this method when you want to create a new path.

注意： To create a new sub-path, i.e., one matching the current canvas state, you can use CanvasRenderingContext2D.moveTo() .

句法

void ctx.beginPath();
					

范例

Creating distinct paths

This example creates two paths, each of which contains a single line.

HTML

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

JavaScript

beginPath() method is called before beginning each line, so that they may be drawn with different colors.

const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');
// First path
ctx.beginPath();
ctx.strokeStyle = 'blue';
ctx.moveTo(20, 20);
ctx.lineTo(200, 20);
ctx.stroke();
// Second path
ctx.beginPath();
ctx.strokeStyle = 'green';
ctx.moveTo(20, 20);
ctx.lineTo(120, 120);
ctx.stroke();
					

结果

规范

规范	状态	注释
HTML 实时标准 The definition of 'CanvasRenderingContext2D.beginPath' 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
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

图例

完整支持

完整支持

另请参阅

• The interface defining this method: CanvasRenderingContext2D
• CanvasRenderingContext2D.closePath()

元数据

• 最后修改： Mar 18, 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()