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• 句法
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

getLineDash() method of the Canvas 2D API's CanvasRenderingContext2D interface gets the current line dash pattern.

句法

ctx.getLineDash();
					

返回值

数组 of numbers that specify distances to alternately draw a line and a gap (in coordinate space units). If the number, when setting the elements, is odd, the elements of the array get copied and concatenated. For example, setting the line dash to [5, 15, 25] will result in getting back [5, 15, 25, 5, 15, 25] .

范例

Getting the current line dash setting

此范例演示 getLineDash() 方法。

HTML

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

JavaScript

As set by setLineDash() , strokes consist of lines that are 10 units wide, with spaces of 20 units in between each line.

const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');
ctx.setLineDash([10, 20]);
console.log(ctx.getLineDash());  // [10, 20]
// Draw a dashed line
ctx.beginPath();
ctx.moveTo(0, 50);
ctx.lineTo(300, 50);
ctx.stroke();
					

结果

规范

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

图例

完整支持

完整支持

另请参阅

• The interface defining this method: CanvasRenderingContext2D
• CanvasRenderingContext2D.setLineDash()
• CanvasRenderingContext2D.lineDashOffset

元数据

• 最后修改： Apr 3, 2020

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()